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Trabalhando com preços na biblioteca DoEasy (Parte 62): atualização em tempo real da série de ticks, preparação para trabalhar com o livro de ofertas

Trabalhando com preços na biblioteca DoEasy (Parte 62): atualização em tempo real da série de ticks, preparação para trabalhar com o livro de ofertas

MetaTrader 5Exemplos | 16 abril 2021, 12:31
833 0
Artyom Trishkin
Artyom Trishkin

Sumário


Ideia

Nós criamos uma coleção de dados de ticks de todos os símbolos usados no programa. A biblioteca é capaz de obter a quantidade necessária de dados de ticks para cada um dos símbolos usados pelo programa e os armazena na coleção de dados de ticks. A coleção de dados de ticks nos permite encontrar qualquer objeto-tick e obter seus dados, podemos filtrar e classificar as listas para pesquisa estatística, mas quando surgem novos ticks de símbolos, esses novos não são inseridos no banco de dados de ticks. Hoje vamos criar esse recurso.

Além disso, cada novo tick aumentará o número de objetos armazenados na coleção. Para limitá-lo e reduzir a quantidade de memória usada, vamos introduzir uma constante com a qual podemos definir o número máximo possível de ticks armazenados no banco de dados da biblioteca para um instrumento. Isso nos protegerá de ficar sem memória. Se o programa usar muitos instrumentos e se já houver um número suficiente de ticks acumulado no banco de dados, a biblioteca apagará automaticamente o número necessário de ticks mais antigos. Assim, sempre teremos o número especificado de ticks para o instrumento. Por padrão, é de 200 000. Esse valor deve ser suficiente para usar estatística com base nos últimos dois dias. Em qualquer caso, o tamanho máximo do número de ticks armazenados na coleção para um instrumento pode sempre ser alterado para atender às nossas necessidades.

Além disso, hoje começaremos a nos preparar para trabalhar com o livro de ofertas. Na classe do objeto-símbolo, criaremos um recurso para acompanhar os dados transmitidos pelo livro de ofertas. Depois, nos próximos artigos começaremos a criar funcionalidades para trabalhar com o livro de ofertas.


Aprimorando as classes da biblioteca

Como tem sido tradição, vamos começar adicionando novas mensagens de texto da biblioteca.
No arquivo \MQL5\Include\DoEasy\Data.mqh escrevemos os índices das novas mensagens:

   MSG_SYM_EVENT_SYMBOL_ADD,                          // Added symbol to Market Watch window
   MSG_SYM_EVENT_SYMBOL_DEL,                          // Symbol removed from Market Watch window
   MSG_SYM_EVENT_SYMBOL_SORT,                         // Changed location of symbols in Market Watch window
   MSG_SYM_SYMBOLS_MODE_CURRENT,                      // Work with current symbol only
   MSG_SYM_SYMBOLS_MODE_DEFINES,                      // Work with predefined symbol list
   MSG_SYM_SYMBOLS_MODE_MARKET_WATCH,                 // Work with Market Watch window symbols
   MSG_SYM_SYMBOLS_MODE_ALL,                          // Work with full list of all available symbols
   MSG_SYM_SYMBOLS_BOOK_ADD,                          // Subscribed to Depth of Market 
   MSG_SYM_SYMBOLS_BOOK_DEL,                          // Unsubscribed from Depth of Market 
   MSG_SYM_SYMBOLS_MODE_BOOK,                         // Subscription to Depth of Market
   
//--- CAccount

e as mensagens de texto correspondentes aos índices adicionados recentemente:

   {"В окно \"Обзор рынка\" добавлен символ","Added symbol to \"Market Watch\" window"},
   {"Из окна \"Обзор рынка\" удалён символ","Removed from \"Market Watch\" window"},
   {"Изменено расположение символов в окне \"Обзор рынка\"","Changed arrangement of symbols in \"Market Watch\" window"},
   {"Работа только с текущим символом","Work only with the current symbol"},
   {"Работа с предопределённым списком символов","Work with predefined list of symbols"},
   {"Работа с символами из окна \"Обзор рынка\"","Working with symbols from \"Market Watch\" window"},
   {"Работа с полным списком всех доступных символов","Work with full list of all available symbols"},
   {"Осуществлена подписка на стакан цен ","Subscribed to Depth of Market"},
   {"Осуществлена отписка от стакан цен ","Unsubscribed from Depth of Market"},
   {"Подписка на стакан цен","Subscription to Depth of Market"},
   
//--- CAccount


Como hoje estaremos fazendo uma atualização em tempo real da coleção de dados de ticks, vamos esclarecer como isso será realizado: quando surge um novo tick entrante (para o símbolo atual), precisamos colocá-lo na estrutura MqlTick para, assim, criar um novo objeto-tick e acrescentá-lo à lista da série de ticks, que é armazenada na coleção junto com as listas de outros símbolos. Mas não podemos obter ticks para outros símbolos no manipulador OnTick() do programa, porque esse manipulador é acionado quando um novo tick do símbolo atual é recebido. Por isso, para obter novos ticks para outros símbolos, precisamos controlá-los no temporizador da biblioteca usando o objeto criado anteriormente da classe "Novo Tick". Para fazer isso, na biblioteca precisamos de mais um temporizador que rastreará os ticks de todos os instrumentos, exceto o atual, para atualizar as listas de dados de tikcs para esses instrumentos.

No arquivo \MQL5\Include\DoEasy\Defines.mqh adicionamos parâmetros do temporizador da coleção de dados de ticks e a constante para especificar o número máximo possível de objetos-ticks para um símbolo:

//--- Parameters of the timer of indicator data timeseries collection
#define COLLECTION_IND_TS_PAUSE        (64)                       // Pause of the timer of indicator data timeseries collection in milliseconds
#define COLLECTION_IND_TS_COUNTER_STEP (16)                       // Increment of indicator data timeseries timer counter
#define COLLECTION_IND_TS_COUNTER_ID   (7)                        // ID of indicator data timeseries timer counter
//--- Parameters of the tick series collection timer
#define COLLECTION_TICKS_PAUSE         (64)                       // Tick series collection timer pause in milliseconds
#define COLLECTION_TICKS_COUNTER_STEP  (16)                       // Tick series timer counter increment step
#define COLLECTION_TICKS_COUNTER_ID    (8)                        // Tick series timer counter ID
//--- Collection list IDs
#define COLLECTION_HISTORY_ID          (0x777A)                   // Historical collection list ID
#define COLLECTION_MARKET_ID           (0x777B)                   // Market collection list ID
#define COLLECTION_EVENTS_ID           (0x777C)                   // Event collection list ID
#define COLLECTION_ACCOUNT_ID          (0x777D)                   // Account collection list ID
#define COLLECTION_SYMBOLS_ID          (0x777E)                   // Symbol collection list ID
#define COLLECTION_SERIES_ID           (0x777F)                   // Timeseries collection list ID
#define COLLECTION_BUFFERS_ID          (0x7780)                   // Indicator buffer collection list ID
#define COLLECTION_INDICATORS_ID       (0x7781)                   // Indicator collection list ID
#define COLLECTION_INDICATORS_DATA_ID  (0x7782)                   // Indicator data collection list ID
#define COLLECTION_TICKSERIES_ID       (0x7783)                   // Tick series collection list ID
//--- Data parameters for file operations
#define DIRECTORY                      ("DoEasy\\")               // Library directory for storing object folders
#define RESOURCE_DIR                   ("DoEasy\\Resource\\")     // Library directory for storing resource folders
//--- Symbol parameters
#define CLR_DEFAULT                    (0xFF000000)               // Default symbol background color in the navigator
#ifdef __MQL5__
   #define SYMBOLS_COMMON_TOTAL        (TerminalInfoInteger(TERMINAL_BUILD)<2430 ? 1000 : 5000)   // Total number of MQL5 working symbols
#else 
   #define SYMBOLS_COMMON_TOTAL        (1000)                     // Total number of MQL4 working symbols
#endif 
//--- Pending request type IDs
#define PENDING_REQUEST_ID_TYPE_ERR    (1)                        // Type of a pending request created based on the server return code
#define PENDING_REQUEST_ID_TYPE_REQ    (2)                        // Type of a pending request created by request
//--- Timeseries parameters
#define SERIES_DEFAULT_BARS_COUNT      (1000)                     // Required default amount of timeseries data
#define PAUSE_FOR_SYNC_ATTEMPTS        (16)                       // Amount of pause milliseconds between synchronization attempts
#define ATTEMPTS_FOR_SYNC              (5)                        // Number of attempts to receive synchronization with the server
//--- Tick series parameters
#define TICKSERIES_DEFAULT_DAYS_COUNT  (1)                        // Required number of days for tick data in default series
#define TICKSERIES_MAX_DATA_TOTAL      (200000)                   // Maximum number of stored tick data of a single symbol
//+------------------------------------------------------------------+

Para poder entender se estamos acompanhando a transmissão de dados do livro de ofertas para determinado símbolo, precisamos adicionar às propriedades do símbolo um parâmetro indicando o status desse acompanhamento. Para fazer isso, adicionamos às propriedades inteiras do símbolo outro parâmetro e aumentamos o número de propriedades inteiras de 36 para 37:

//+------------------------------------------------------------------+
//| Symbol integer properties                                        |
//+------------------------------------------------------------------+
enum ENUM_SYMBOL_PROP_INTEGER
  {
   SYMBOL_PROP_STATUS = 0,                                  // Symbol status
   SYMBOL_PROP_INDEX_MW,                                    // Symbol index in the Market Watch window
   SYMBOL_PROP_CUSTOM,                                      // Custom symbol flag
   SYMBOL_PROP_CHART_MODE,                                  // The price type used for generating bars – Bid or Last (from the ENUM_SYMBOL_CHART_MODE enumeration)
   SYMBOL_PROP_EXIST,                                       // Flag indicating that the symbol under this name exists
   SYMBOL_PROP_SELECT,                                      // The indication that the symbol is selected in Market Watch
   SYMBOL_PROP_VISIBLE,                                     // The indication that the symbol is displayed in Market Watch
   SYMBOL_PROP_SESSION_DEALS,                               // The number of deals in the current session 
   SYMBOL_PROP_SESSION_BUY_ORDERS,                          // The total number of Buy orders at the moment
   SYMBOL_PROP_SESSION_SELL_ORDERS,                         // The total number of Sell orders at the moment
   SYMBOL_PROP_VOLUME,                                      // Last deal volume
   SYMBOL_PROP_VOLUMEHIGH,                                  // Maximum volume within a day
   SYMBOL_PROP_VOLUMELOW,                                   // Minimum volume within a day
   SYMBOL_PROP_TIME,                                        // Latest quote time
   SYMBOL_PROP_DIGITS,                                      // Number of decimal places
   SYMBOL_PROP_DIGITS_LOTS,                                 // Number of decimal places for a lot
   SYMBOL_PROP_SPREAD,                                      // Spread in points
   SYMBOL_PROP_SPREAD_FLOAT,                                // Floating spread flag
   SYMBOL_PROP_TICKS_BOOKDEPTH,                             // Maximum number of orders displayed in the Depth of Market
   SYMBOL_PROP_BOOKDEPTH_STATE,                             // Flag of subscription to DOM
   SYMBOL_PROP_TRADE_CALC_MODE,                             // Contract price calculation method (from the ENUM_SYMBOL_CALC_MODE enumeration)
   SYMBOL_PROP_TRADE_MODE,                                  // Order execution type (from the ENUM_SYMBOL_TRADE_MODE enumeration)
   SYMBOL_PROP_START_TIME,                                  // Symbol trading start date (usually used for futures)
   SYMBOL_PROP_EXPIRATION_TIME,                             // Symbol trading end date (usually used for futures)
   SYMBOL_PROP_TRADE_STOPS_LEVEL,                           // Minimum distance in points from the current close price for setting Stop orders
   SYMBOL_PROP_TRADE_FREEZE_LEVEL,                          // Freeze distance for trading operations (in points)
   SYMBOL_PROP_TRADE_EXEMODE,                               // Deal execution mode (from the ENUM_SYMBOL_TRADE_EXECUTION enumeration)
   SYMBOL_PROP_SWAP_MODE,                                   // Swap calculation model (from the ENUM_SYMBOL_SWAP_MODE enumeration)
   SYMBOL_PROP_SWAP_ROLLOVER3DAYS,                          // Triple-day swap (from the ENUM_DAY_OF_WEEK enumeration)
   SYMBOL_PROP_MARGIN_HEDGED_USE_LEG,                       // Calculating hedging margin using the larger leg (Buy or Sell)
   SYMBOL_PROP_EXPIRATION_MODE,                             // Flags of allowed order expiration modes
   SYMBOL_PROP_FILLING_MODE,                                // Flags of allowed order filling modes
   SYMBOL_PROP_ORDER_MODE,                                  // Flags of allowed order types
   SYMBOL_PROP_ORDER_GTC_MODE,                              // Expiration of Stop Loss and Take Profit orders if SYMBOL_EXPIRATION_MODE=SYMBOL_EXPIRATION_GTC (from the ENUM_SYMBOL_ORDER_GTC_MODE enumeration)
   SYMBOL_PROP_OPTION_MODE,                                 // Option type (from the ENUM_SYMBOL_OPTION_MODE enumeration)
   SYMBOL_PROP_OPTION_RIGHT,                                // Option right (Call/Put) (from the ENUM_SYMBOL_OPTION_RIGHT enumeration)
   //--- skip the property
   SYMBOL_PROP_BACKGROUND_COLOR                             // The color of the background used for the symbol in Market Watch
  }; 
#define SYMBOL_PROP_INTEGER_TOTAL    (37)                   // Total number of integer properties
#define SYMBOL_PROP_INTEGER_SKIP     (1)                    // Number of symbol integer properties not used in sorting
//+------------------------------------------------------------------+

Em enumerações de possíveis critérios para classificar objetos-símbolos, adicionamos a classificação por nova propriedade inteira:

//+------------------------------------------------------------------+
//| Possible symbol sorting criteria                                 |
//+------------------------------------------------------------------+
#define FIRST_SYM_DBL_PROP          (SYMBOL_PROP_INTEGER_TOTAL-SYMBOL_PROP_INTEGER_SKIP)
#define FIRST_SYM_STR_PROP          (SYMBOL_PROP_INTEGER_TOTAL-SYMBOL_PROP_INTEGER_SKIP+SYMBOL_PROP_DOUBLE_TOTAL-SYMBOL_PROP_DOUBLE_SKIP)
enum ENUM_SORT_SYMBOLS_MODE
  {
//--- Sort by integer properties
   SORT_BY_SYMBOL_STATUS = 0,                               // Sort by symbol status
   SORT_BY_SYMBOL_INDEX_MW,                                 // Sort by index in the Market Watch window
   SORT_BY_SYMBOL_CUSTOM,                                   // Sort by custom symbol property
   SORT_BY_SYMBOL_CHART_MODE,                               // Sort by price type for constructing bars – Bid or Last (from the ENUM_SYMBOL_CHART_MODE enumeration)
   SORT_BY_SYMBOL_EXIST,                                    // Sort by the flag that a symbol with such a name exists
   SORT_BY_SYMBOL_SELECT,                                   // Sort by the flag indicating that a symbol is selected in Market Watch
   SORT_BY_SYMBOL_VISIBLE,                                  // Sort by the flag indicating that a selected symbol is displayed in Market Watch
   SORT_BY_SYMBOL_SESSION_DEALS,                            // Sort by the number of deals in the current session 
   SORT_BY_SYMBOL_SESSION_BUY_ORDERS,                       // Sort by the total number of current buy orders
   SORT_BY_SYMBOL_SESSION_SELL_ORDERS,                      // Sort by the total number of current sell orders
   SORT_BY_SYMBOL_VOLUME,                                   // Sort by last deal volume
   SORT_BY_SYMBOL_VOLUMEHIGH,                               // Sort by maximum volume for a day
   SORT_BY_SYMBOL_VOLUMELOW,                                // Sort by minimum volume for a day
   SORT_BY_SYMBOL_TIME,                                     // Sort by the last quote time
   SORT_BY_SYMBOL_DIGITS,                                   // Sort by a number of decimal places
   SORT_BY_SYMBOL_DIGITS_LOT,                               // Sort by a number of decimal places in a lot
   SORT_BY_SYMBOL_SPREAD,                                   // Sort by spread in points
   SORT_BY_SYMBOL_SPREAD_FLOAT,                             // Sort by floating spread
   SORT_BY_SYMBOL_TICKS_BOOKDEPTH,                          // Sort by a maximum number of requests displayed in the market depth
   SORT_BY_SYMBOL_BOOKDEPTH_STATE,                          // Sort by the DOM subscription flag
   SORT_BY_SYMBOL_TRADE_CALC_MODE,                          // Sort by contract price calculation method (from the ENUM_SYMBOL_CALC_MODE enumeration)
   SORT_BY_SYMBOL_TRADE_MODE,                               // Sort by order execution type (from the ENUM_SYMBOL_TRADE_MODE enumeration)
   SORT_BY_SYMBOL_START_TIME,                               // Sort by an instrument trading start date (usually used for futures)
   SORT_BY_SYMBOL_EXPIRATION_TIME,                          // Sort by an instrument trading end date (usually used for futures)
   SORT_BY_SYMBOL_TRADE_STOPS_LEVEL,                        // Sort by the minimum indent from the current close price (in points) for setting Stop orders
   SORT_BY_SYMBOL_TRADE_FREEZE_LEVEL,                       // Sort by trade operation freeze distance (in points)
   SORT_BY_SYMBOL_TRADE_EXEMODE,                            // Sort by trade execution mode (from the ENUM_SYMBOL_TRADE_EXECUTION enumeration)
   SORT_BY_SYMBOL_SWAP_MODE,                                // Sort by swap calculation model (from the ENUM_SYMBOL_SWAP_MODE enumeration)
   SORT_BY_SYMBOL_SWAP_ROLLOVER3DAYS,                       // Sort by week day for accruing a triple swap (from the ENUM_DAY_OF_WEEK enumeration)
   SORT_BY_SYMBOL_MARGIN_HEDGED_USE_LEG,                    // Sort by the calculation mode of a hedged margin using the larger leg (Buy or Sell)
   SORT_BY_SYMBOL_EXPIRATION_MODE,                          // Sort by flags of allowed order expiration modes
   SORT_BY_SYMBOL_FILLING_MODE,                             // Sort by flags of allowed order filling modes
   SORT_BY_SYMBOL_ORDER_MODE,                               // Sort by flags of allowed order types
   SORT_BY_SYMBOL_ORDER_GTC_MODE,                           // Sort by StopLoss and TakeProfit orders lifetime
   SORT_BY_SYMBOL_OPTION_MODE,                              // Sort by option type (from the ENUM_SYMBOL_OPTION_MODE enumeration)
   SORT_BY_SYMBOL_OPTION_RIGHT,                             // Sort by option right (Call/Put) (from the ENUM_SYMBOL_OPTION_RIGHT enumeration)
//--- Sort by real properties



Atualizando série de ticks

Uma vez que os ticks podem vir simultaneamente num pacote de uma vez, não podemos adicioná-los um por um, tick a tick, à lista de séries de ticks. Para salvar todos os ticks recebidos num lote, precisamos controlar o tempo em milissegundos do último tick recebido e copiar os ticks desde esse momento até o final dos dados históricos. Após copiar todos os ticks recém-chegados (e isso pode ser um tick ou vários de uma vez num pacote), precisamos salvar a hora do último deles. Para, na próximo ativação de OnTick(), começar a copiar os ticks deste momento + 1 milissegundo (para que o último tick não seja copiado novamente) até o final dos dados do histórico - até a hora atual. Assim, a cada noca ativação de OnTick(), sempre poderemos receber todos os dados necessários que surgiram com a chegada de um novo tick, e ao finalizar a cópia, saber a nova hora do último tick para a posterior cópia.

Ao criar um método para atualizar uma série de ticks, ficamos a saber que criar um novo objeto de dados de ticks e adicioná-lo à lista de séries de tick é como criar um novo objeto de dados de tick e adicioná-lo à lista no método de geração de série de ticks já criado. Por isso, este bloco de código foi movido para um novo método que retorna um ponteiro para o objeto recém-criado e adicionado à lista, ou NULL. Abaixo discutiremos este novo método, um método modificado para criar uma lista e um novo método para atualizar uma lista.

Na seção privada do arquivo \MQL5\Include\DoEasy\Objects\Ticks\TickSeries.mqh declaramos uma variável-membro de classe para armazenar o tempo em milissegundos do último ticks e o método para criar um novo objeto-tick e adicioná-lo à lista de séries de ticks:

//+------------------------------------------------------------------+
//| "Tick data series" class                                         |
//+------------------------------------------------------------------+
class CTickSeries : public CBaseObj
  {
private:
   string            m_symbol;                                          // Symbol
   ulong             m_last_time;                                       // Last tick time
   uint              m_amount;                                          // Amount of applied tick series data
   uint              m_required;                                        // Required number of days for tick series data
   CArrayObj         m_list_ticks;                                      // List of tick data
   CNewTickObj       m_new_tick_obj;                                    // "New tick" object
//--- Create a new tick data object
   CDataTick        *CreateNewTickObj(const MqlTick &tick);

public:

Na seção pública da classe declaramos um método que retorna um ponteiro para o último objeto de dados de ticks na lista:

//--- Return the object of tick data by (1) index in the list, (2) time,
//--- (3) time in milliseconds, (4) the last one in the list and (5) the list size
   CDataTick        *GetTickByListIndex(const uint index);
   CDataTick        *GetTick(const datetime time); 
   CDataTick        *GetTick(const ulong time_msc); 
   CDataTick        *GetLastTick(void); 
   int               DataTotal(void)                              const { return this.m_list_ticks.Total();       }

//--- The comparison method for searching identical tick series objects by a symbol

Como precisamos usar o objeto "Novo Ticks", para seu correto funcionamento precisamos especificar o símbolo de trabalho.
Vamos fazer isso no construtor de classe:

//+------------------------------------------------------------------+
//| Parametric constructor                                           |
//+------------------------------------------------------------------+
CTickSeries::CTickSeries(const string symbol,const uint required=0) : m_symbol(symbol),m_last_time(0)
  {
   this.m_list_ticks.Clear();
   this.m_list_ticks.Sort(SORT_BY_TICK_TIME_MSC);
   this.SetRequiredUsedDays(required);
   this.m_new_tick_obj.SetSymbol(this.m_symbol);
   this.m_new_tick_obj.Refresh();
  }
//+------------------------------------------------------------------+

Após definir o símbolo imediatamente uma vez atualizamos os dados no objeto "Novo Tick" para saber a hora do último tick neste objeto.

Método que cria um novo objeto de dados tick e o coloca na lista:

//+------------------------------------------------------------------+
//| Create a new tick data object                                    |
//+------------------------------------------------------------------+
CDataTick *CTickSeries::CreateNewTickObj(const MqlTick &tick)
  {
   //--- create a new object of tick data out of the MqlTick structure passed to the method
   int err=ERR_SUCCESS;
   ::ResetLastError();
   //--- If failed to create an object, inform of that and return NULL
   CDataTick* tick_obj=new CDataTick(this.m_symbol,tick);
   if(tick_obj==NULL)
     {
      ::Print
        (
         DFUN,CMessage::Text(MSG_TICKSERIES_FAILED_CREATE_TICK_DATA_OBJ)," ",this.Header()," ",::TimeMSCtoString(tick.time_msc),". ",
         CMessage::Text(MSG_LIB_SYS_ERROR),": ",CMessage::Text(::GetLastError())
        );
      return NULL;
     }
   //--- If failed to add a new tick data object to the list,
   //--- display the appropriate message with the error description in the journal,
   //--- remove the newly created object and return NULL
   this.m_list_ticks.Sort();
   if(!this.m_list_ticks.InsertSort(tick_obj))
     {
      err=::GetLastError();
      ::Print(DFUN,CMessage::Text(MSG_TICKSERIES_FAILED_ADD_TO_LIST)," ",tick_obj.Header()," ",
                   CMessage::Text(MSG_LIB_SYS_ERROR),": ",CMessage::Text(err),CMessage::Retcode(err));
      delete tick_obj;
      return NULL;
     }
   //--- Return the pointer to the tick data object that was created and added to the list
   return tick_obj;
  }
//+------------------------------------------------------------------+

No método, toda a sua lógica é descrita nos comentários. Foi este bloco de código que foi transferido para este novo método a partir do método de criação de uma lista de séries de ticks, feita por nós no último artigo. Agora para este método é transferida a estrutura do tick cujos dados permitirão criar um novo objeto de dados de ticks. Após concluída sua criação e adicioná-la à lista, um ponteiro para este objeto é retornado, ou NULL caso o objeto não possa ser criado ou adicionado à lista.

Método que cria uma lista-série de dados de ticks:

//+------------------------------------------------------------------+
//| Create the series list of tick data                              |
//+------------------------------------------------------------------+
int CTickSeries::Create(const uint required=0)
  {
//--- If the tick series is not used, inform of that and exit
   if(!this.m_available)
     {
      ::Print(DFUN,this.m_symbol,": ",CMessage::Text(MSG_TICKSERIES_TEXT_IS_NOT_USE));
      return false;
     }
//--- Declare the ticks[] array we are to receive historical data to,
//--- clear the list of tick data objects and set the flag of sorting by time in milliseconds
   MqlTick ticks_array[];
   this.m_list_ticks.Clear();
   this.m_list_ticks.Sort(SORT_BY_TICK_TIME_MSC);
   this.m_last_time=0;
   ::ResetLastError();
   int err=ERR_SUCCESS;
//--- Calculate the day start time in milliseconds the ticks should be copied from
   MqlDateTime date_str={0};
   datetime date=::iTime(m_symbol,PERIOD_D1,this.m_required);
   ::TimeToStruct(date,date_str);
   date_str.hour=date_str.min=date_str.sec=0;
   date=::StructToTime(date_str);
   long date_from=(long)date*1000;
   if(date_from<1) date_from=1;
//--- Get historical data of the MqlTick structure to the tick[] array
//--- from the calculated date to the current time and save the obtained number in m_amount.
//--- If failed to get data, display the appropriate message and return zero
   this.m_amount=::CopyTicksRange(m_symbol,ticks_array,COPY_TICKS_ALL,date_from);
   if(this.m_amount<1)
     {
      err=::GetLastError();
      ::Print(DFUN,CMessage::Text(MSG_TICKSERIES_ERR_GET_TICK_DATA),": ",CMessage::Text(err),CMessage::Retcode(err));
      return 0;
     }
//--- Historical data is received in the rates[] array
//--- In the ticks[] array loop
   for(int i=0; i<(int)this.m_amount; i++)
     {
      //--- Create the tick object and add it to the list
      CDataTick *tick_obj=this.CreateNewTickObj(ticks_array[i]);
      if(tick_obj==NULL)
         continue;
      //--- If the tick time exceeds the previous one, write the new tick time to m_last_time as the starting one
      //--- to copy the newly arrived ticks in the tick series update method
      if(this.m_last_time<(ulong)tick_obj.TimeMSC())
         this.m_last_time=tick_obj.TimeMSC();
     }
//--- Return the size of the created tick object list
   return this.m_list_ticks.Total();
  }
//+------------------------------------------------------------------+

O método foi escrito por nós no artigo dedicado à criação de séries de ticks, mas aqui vamos modificá-lo para criar e adicionar um novo objeto de dados de ticks usando o novo método discutido acima. Após adicionar com sucesso o objeto à lista salvamos o tempo do último tick para seu uso posterior no método de atualização da série de ticks.

Método para atualizar uma série de ticks:

//+------------------------------------------------------------------+
//| Update the tick series list                                      |
//+------------------------------------------------------------------+
void CTickSeries::Refresh(void)
  {
   MqlTick ticks_array[];
   if(IsNewTick())
     {
      //--- Copy ticks from m_last_time time+1 ms to the end of history
      int err=ERR_SUCCESS;
      int total=::CopyTicksRange(this.Symbol(),ticks_array,COPY_TICKS_ALL,this.m_last_time+1,0);
      //--- If the ticks have been copied, create new tick data objects and add them to the list in the loop by their number
      if(total>0)
        {
         for(int i=0;i<total;i++)
           {
            //--- Create the tick object and add it to the list
            CDataTick *tick_obj=this.CreateNewTickObj(ticks_array[i]);
            if(tick_obj==NULL)
               break;
            //--- Write the last tick time for subsequent copying of newly arrived ticks
            long end_time=ticks_array[::ArraySize(ticks_array)-1].time_msc;
            if(this.Symbol()=="AUDUSD")
               Comment(DFUN,this.Symbol(),", copied=",total,", m_last_time=",TimeMSCtoString(m_last_time),", end_time=",TimeMSCtoString(end_time),", total=",DataTotal());
            this.m_last_time=end_time;
           }
         //--- If the number of ticks in the list exceeds the default maximum number,
         //--- remove the calculated number of tick objects from the end of the list
         if(this.DataTotal()>TICKSERIES_MAX_DATA_TOTAL)
           {
            int total_del=m_list_ticks.Total()-TICKSERIES_MAX_DATA_TOTAL;
            for(int j=0;j<total_del;j++)
               this.m_list_ticks.Delete(j);
           }
        }
     }
  }
//+------------------------------------------------------------------+

Aqui tudo é simples, basta termos a hora do último tick, fixada na última ativação de OnTick(), armazenada na variável m_last_time. Agora, para começar a copiar novos ticks, precisamos adicionar um milissegundo a este tempo, uma vez que a função CopyTicksRange() cópias a partir da hora especificada, Incluindo este tempo. Precisamente para não termos que incluir na lista-série o objeto-tick que foi copiado nos ticks copiados após uma nova ativação de OnTick(), nós começamos a copiar não a partir do tempo fixado no último tick, mas a partir do tempo com uma diferença de um milissegundo. Se, apóscopiar novos ticks e adicioná-los à lista, seu número total exceder o valor máximo definido, calcularemos o número de objetos desnecessários na lista e os removeremos da lista - são os objetos-ticks mais antigos da lista.

Ao método foram adicionadas propositalmente linhas de código que exibiam dados sobre o número de ticks copiados, hora passada e atual e a quantidade total de dados de ticks na lista de série de ticks - para verificar sua cópia (AUDUSD).
Removeremos essas linhas de teste nos próximos artigos. Agora, essas linhas serão capazes de nos mostrar que os ticks de um símbolo "não nativo" são copiados no temporizador da biblioteca e os objetos de dados de ticks são adicionados à lista de séries de ticks.

Método que retorna o objeto de dados de ticks mais recente da lista:

//+------------------------------------------------------------------+
//| Return the most recent tick data object from the list            |
//+------------------------------------------------------------------+
CDataTick *CTickSeries::GetLastTick(void)
  {
   return this.m_list_ticks.At(this.m_list_ticks.Total()-1);
  }
//+------------------------------------------------------------------+

O método simplesmente retorna um ponteiro para o objeto mais recente da lista.

Agora vamos modificar um pouco a classe-coleção da série de ticks no arquivo \MQL5\Include\DoEasy\Collections\TickSeriesCollection.mqh.

Uma vez que precisamos atualizar separadamente as séries de ticks do símbolo atual e as dos outros - vamos atualizar a série do símbolo atual no manipulador OnTick() da biblioteca, e os dados de ticks restantes de outros símbolos - no temporizador da biblioteca, criaremos um método que atualiza todas as séries de ticks da coleção, exceto para a série do símbolo atual. Na seção pública da classe, declaramos o método:

//--- Update (1) a tick series of a specified symbol, (2) all symbols and (3) all symbols except the current one
   void                    Refresh(const string symbol);
   void                    Refresh(void);
   void                    RefreshExpectCurrent(void);

//--- Display (1) the complete and (2) short collection description in the journal

e fora do corpo da classe, escrevemos sua implementação:

//+------------------------------------------------------------------+
//| Update tick series of all symbols except the current one         |
//+------------------------------------------------------------------+
void CTickSeriesCollection::RefreshExpectCurrent(void)
  {
   for(int i=0;i<this.m_list.Total();i++)
     {
      CTickSeries *tickseries=this.m_list.At(i);
      if(tickseries==NULL || tickseries.Symbol()==::Symbol())
         continue;
      tickseries.Refresh();
     }
  }
//+------------------------------------------------------------------+

Num loop sobre o número total de séries de ticks na coleção, obtemos o próximo objeto da série de ticks a partir da lista e, se seu símbolo for igual ao símbolo do gráfico no qual o programa está sendo executado, pulamos esta série. Atualizamos todas as outras séries de ticks.

Ao objeto principal da biblioteca CEngine no arquivo \MQL5\Include\DoEasy\Engine.mqh adicionamos três métodos: um para atualizar a série de ticks do símbolo especificado, um para atualizar todas as séries de ticks e outro para atualizar todas as séries de ticks da coleção, exceto para a série do símbolo atual:

//--- Return (1) the tick series collection, (2) the list of tick series from the tick series collection
   CTickSeriesCollection *GetTickSeriesCollection(void)                                { return &this.m_tick_series;                         }
   CArrayObj           *GetListTickSeries(void)                                        { return this.m_tick_series.GetList();                }

//--- Update (1) a tick series of a specified symbol, (2) all symbols and (3) all symbols except the current one
   void                 TickSeriesRefresh(const string symbol)                         { this.m_tick_series.Refresh(symbol);                 }
   void                 TickSeriesRefreshAll(void)                                     { this.m_tick_series.Refresh();                       }
   void                 TickSeriesRefreshAllExceptCurrent(void)                        { this.m_tick_series.RefreshExpectCurrent();          }

//--- Return (1) the buffer collection and (2) the buffer list from the collection 

Os métodos simplesmente chamam os métodos da classe-coleção da série de ticks.

No construtor da classe adicionamos a criação de um temporizador para a coleção de dados de ticks:

//+------------------------------------------------------------------+
//| CEngine constructor                                              |
//+------------------------------------------------------------------+
CEngine::CEngine() : m_first_start(true),
                     m_last_trade_event(TRADE_EVENT_NO_EVENT),
                     m_last_account_event(WRONG_VALUE),
                     m_last_symbol_event(WRONG_VALUE),
                     m_global_error(ERR_SUCCESS)
  {
   this.m_is_hedge=#ifdef __MQL4__ true #else bool(::AccountInfoInteger(ACCOUNT_MARGIN_MODE)==ACCOUNT_MARGIN_MODE_RETAIL_HEDGING) #endif;
   this.m_is_tester=::MQLInfoInteger(MQL_TESTER);
   this.m_program=(ENUM_PROGRAM_TYPE)::MQLInfoInteger(MQL_PROGRAM_TYPE);
   this.m_name=::MQLInfoString(MQL_PROGRAM_NAME);
   
   this.m_list_counters.Sort();
   this.m_list_counters.Clear();
   this.CreateCounter(COLLECTION_ORD_COUNTER_ID,COLLECTION_ORD_COUNTER_STEP,COLLECTION_ORD_PAUSE);
   this.CreateCounter(COLLECTION_ACC_COUNTER_ID,COLLECTION_ACC_COUNTER_STEP,COLLECTION_ACC_PAUSE);
   this.CreateCounter(COLLECTION_SYM_COUNTER_ID1,COLLECTION_SYM_COUNTER_STEP1,COLLECTION_SYM_PAUSE1);
   this.CreateCounter(COLLECTION_SYM_COUNTER_ID2,COLLECTION_SYM_COUNTER_STEP2,COLLECTION_SYM_PAUSE2);
   this.CreateCounter(COLLECTION_REQ_COUNTER_ID,COLLECTION_REQ_COUNTER_STEP,COLLECTION_REQ_PAUSE);
   this.CreateCounter(COLLECTION_TS_COUNTER_ID,COLLECTION_TS_COUNTER_STEP,COLLECTION_TS_PAUSE);
   this.CreateCounter(COLLECTION_IND_TS_COUNTER_ID,COLLECTION_IND_TS_COUNTER_STEP,COLLECTION_IND_TS_PAUSE);
   this.CreateCounter(COLLECTION_TICKS_COUNTER_ID,COLLECTION_TICKS_COUNTER_STEP,COLLECTION_TICKS_PAUSE);
   
   ::ResetLastError();
   #ifdef __MQL5__
      if(!::EventSetMillisecondTimer(TIMER_FREQUENCY))
        {
         ::Print(DFUN_ERR_LINE,CMessage::Text(MSG_LIB_SYS_FAILED_CREATE_TIMER),(string)::GetLastError());
         this.m_global_error=::GetLastError();
        }
   //---__MQL4__
   #else 
      if(!this.IsTester() && !::EventSetMillisecondTimer(TIMER_FREQUENCY))
        {
         ::Print(DFUN_ERR_LINE,CMessage::Text(MSG_LIB_SYS_FAILED_CREATE_TIMER),(string)::GetLastError());
         this.m_global_error=::GetLastError();
        }
   #endif 
   //---
  }
//+------------------------------------------------------------------+

Agora o temporizador da coleção de séries de ticks foi criado, e precisamos especificar no temporizador da classe o bloco de trabalho com este temporizador:

//+------------------------------------------------------------------+
//| CEngine timer                                                    |
//+------------------------------------------------------------------+
void CEngine::OnTimer(SDataCalculate &data_calculate)
  {
//--- If this is not a tester, work with collection events by timer
   if(!this.IsTester())
     {
   //--- Timer of the collections of historical orders and deals, as well as of market orders and positions
      int index=this.CounterIndex(COLLECTION_ORD_COUNTER_ID);
      CTimerCounter* cnt1=this.m_list_counters.At(index);
      if(cnt1!=NULL)
        {
         //--- If unpaused, work with the order, deal and position collections events
         if(cnt1.IsTimeDone())
            this.TradeEventsControl();
        }
   //--- Account collection timer
      index=this.CounterIndex(COLLECTION_ACC_COUNTER_ID);
      CTimerCounter* cnt2=this.m_list_counters.At(index);
      if(cnt2!=NULL)
        {
         //--- If unpaused, work with the account collection events
         if(cnt2.IsTimeDone())
            this.AccountEventsControl();
        }
   //--- Timer 1 of the symbol collection (updating symbol quote data in the collection)
      index=this.CounterIndex(COLLECTION_SYM_COUNTER_ID1);
      CTimerCounter* cnt3=this.m_list_counters.At(index);
      if(cnt3!=NULL)
        {
         //--- If the pause is over, update quote data of all symbols in the collection
         if(cnt3.IsTimeDone())
            this.m_symbols.RefreshRates();
        }
   //--- Timer 2 of the symbol collection (updating all data of all symbols in the collection and tracking symbl and symbol search events in the market watch window)
      index=this.CounterIndex(COLLECTION_SYM_COUNTER_ID2);
      CTimerCounter* cnt4=this.m_list_counters.At(index);
      if(cnt4!=NULL)
        {
         //--- If the pause is over
         if(cnt4.IsTimeDone())
           {
            //--- update data and work with events of all symbols in the collection
            this.SymbolEventsControl();
            //--- When working with the market watch list, check the market watch window events
            if(this.m_symbols.ModeSymbolsList()==SYMBOLS_MODE_MARKET_WATCH)
               this.MarketWatchEventsControl();
           }
        }
   //--- Trading class timer
      index=this.CounterIndex(COLLECTION_REQ_COUNTER_ID);
      CTimerCounter* cnt5=this.m_list_counters.At(index);
      if(cnt5!=NULL)
        {
         //--- If unpaused, work with the list of pending requests
         if(cnt5.IsTimeDone())
            this.m_trading.OnTimer();
        }
   //--- Timeseries collection timer
      index=this.CounterIndex(COLLECTION_TS_COUNTER_ID);
      CTimerCounter* cnt6=this.m_list_counters.At(index);
      if(cnt6!=NULL)
        {
         //--- If the pause is over, work with the timeseries list (update all except the current one)
         if(cnt6.IsTimeDone())
            this.SeriesRefreshAllExceptCurrent(data_calculate);
        }
        
   //--- Timer of timeseries collection of indicator buffer data
      index=this.CounterIndex(COLLECTION_IND_TS_COUNTER_ID);
      CTimerCounter* cnt7=this.m_list_counters.At(index);
      if(cnt7!=NULL)
        {
         //--- If the pause is over, work with the timeseries list of indicator data (update all except for the current one)
         if(cnt7.IsTimeDone()) 
            this.IndicatorSeriesRefreshAll();
        }
   //--- Tick series collection timer
      index=this.CounterIndex(COLLECTION_TICKS_COUNTER_ID);
      CTimerCounter* cnt8=this.m_list_counters.At(index);
      if(cnt8!=NULL)
        {
         //--- If the pause is over, work with the tick series list (update all except the current one)
         if(cnt8.IsTimeDone())
            this.TickSeriesRefreshAllExceptCurrent();
        }
     }
//--- If this is a tester, work with collection events by tick
   else
     {
      //--- work with events of collections of orders, deals and positions by tick
      this.TradeEventsControl();
      //--- work with events of collections of accounts by tick
      this.AccountEventsControl();
      //--- update quote data of all collection symbols by tick
      this.m_symbols.RefreshRates();
      //--- work with events of all symbols in the collection by tick
      this.SymbolEventsControl();
      //--- work with the list of pending orders by tick
      this.m_trading.OnTimer();
      //--- work with the timeseries list by tick
      this.SeriesRefresh(data_calculate);
      //--- work with the timeseries list of indicator buffers by tick
      this.IndicatorSeriesRefreshAll();
      //--- work with the list of tick series by tick
      this.TickSeriesRefreshAll();
     }
  }
//+------------------------------------------------------------------+

Agora, todas as séries de ticks de todos os símbolos "não nativos" serão atualizadas no temporizador da biblioteca.

Para atualizar a série de ticks do símbolo atual, no manipulador OnTick() da classe inserimos uma chamada do método para atualizar a série de ticks do símbolo especificado:

//+------------------------------------------------------------------+
//| NewTick event handler                                            |
//+------------------------------------------------------------------+
void CEngine::OnTick(SDataCalculate &data_calculate,const uint required=0)
  {
//--- If this is not a EA, exit
   if(this.m_program!=PROGRAM_EXPERT)
      return;
//--- Re-create empty timeseries and update the current symbol timeseries
   this.SeriesSync(data_calculate,required);
   this.SeriesRefresh(NULL,data_calculate);
   this.TickSeriesRefresh(NULL);
//--- end
  }
//+------------------------------------------------------------------+

Agora a série de ticks do símbolo atual será atualizada na chegada de um novo tick, e todas as outras séries de ticks de outros símbolos serão atualizadas no temporizador da biblioteca.


Aprimorando a classe do símbolo para trabalhar com o livro de ofertas

A partir do próximo artigo, começaremos a criar a funcionalidade de biblioteca para trabalhar com o livro de ofertas.

Para receber eventos BookEvent de qualquer símbolo, basta acompanhar esses eventos para este símbolo usando a função MarketBookAdd(). Para cancelar o recebimento do evento BookEvent para um símbolo específico, precisamos chamar a função MarketBookRelease().

Cada integração do livro de ofertas deve corresponder à sua remoção, o que pode ser feito facilmente na classe - no construtor integramos o livro de ofertas, já no destruidor o desabilitamos. Para cada símbolo, criamos nosso próprio objeto-símbolo e, para cada um desses objetos-símbolos, podemos saber claramente quando o livro de ofertas está integrado e quando precisa ser desabilitado.

Vamos abrir a classe do objeto-símbolo no arquivo \MQL5\Include\DoEasy\Objects\Symbols\Symbol.mqh e inserimos as alterações necessárias.
Na seção privada da classe declaramos uma variável para armazenar o sinalizador que indica o acompanhamento do livro de ofertas, e na seção pública declaramos um destruidor de classe:

//+------------------------------------------------------------------+
//| Abstract symbol class                                            |
//+------------------------------------------------------------------+
class CSymbol : public CBaseObjExt
  {
private:
   struct MqlMarginRate
     {
      double         Initial;                                  // initial margin rate
      double         Maintenance;                              // maintenance margin rate
     };
   struct MqlMarginRateMode
     {
      MqlMarginRate  Long;                                     // MarginRate of long positions
      MqlMarginRate  Short;                                    // MarginRate of short positions
      MqlMarginRate  BuyStop;                                  // MarginRate of BuyStop orders
      MqlMarginRate  BuyLimit;                                 // MarginRate of BuyLimit orders
      MqlMarginRate  BuyStopLimit;                             // MarginRate of BuyStopLimit orders
      MqlMarginRate  SellStop;                                 // MarginRate of SellStop orders
      MqlMarginRate  SellLimit;                                // MarginRate of SellLimit orders
      MqlMarginRate  SellStopLimit;                            // MarginRate of SellStopLimit orders
     };
   MqlMarginRateMode m_margin_rate;                            // Margin ratio structure
   MqlBookInfo       m_book_info_array[];                      // Array of the market depth data structures
   
   long              m_long_prop[SYMBOL_PROP_INTEGER_TOTAL];   // Integer properties
   double            m_double_prop[SYMBOL_PROP_DOUBLE_TOTAL];  // Real properties
   string            m_string_prop[SYMBOL_PROP_STRING_TOTAL];  // String properties
   bool              m_is_change_trade_mode;                   // Flag of changing trading mode for a symbol
   bool              m_book_subscribed;                        // FLag of subscribing to the Depth of Market by symbol
   CTradeObj         m_trade;                                  // Trading class object
//--- Return the index of the array the symbol's (1) double and (2) string properties are located at
   int               IndexProp(ENUM_SYMBOL_PROP_DOUBLE property)  const { return(int)property-SYMBOL_PROP_INTEGER_TOTAL;                                    }
   int               IndexProp(ENUM_SYMBOL_PROP_STRING property)  const { return(int)property-SYMBOL_PROP_INTEGER_TOTAL-SYMBOL_PROP_DOUBLE_TOTAL;           }
//--- (1) Fill in all the "margin ratio" symbol properties, (2) initialize the ratios
-+/   bool              MarginRates(void);
   void              InitMarginRates(void);
//--- Reset all symbol object data
   void              Reset(void);
//--- Return the current day of the week
   ENUM_DAY_OF_WEEK  CurrentDayOfWeek(void)              const;

public:
//--- Default constructor
                     CSymbol(void){;}
//--- Destructor
                    ~CSymbol(void);
protected:
//--- Protected parametric constructor
                     CSymbol(ENUM_SYMBOL_STATUS symbol_status,const string name,const int index);


Na seção pública da classe nos métodos de acesso simplificado às propriedades do símbolo vamos escrever um novo método que retorna o status do acompanhamento do livro de ofertas:

public:
//+------------------------------------------------------------------+
//| Methods of a simplified access to the order object properties    |
//+------------------------------------------------------------------+
//--- Integer properties
   long              Status(void)                                 const { return this.GetProperty(SYMBOL_PROP_STATUS);                                      }
   int               IndexInMarketWatch(void)                     const { return (int)this.GetProperty(SYMBOL_PROP_INDEX_MW);                               }
   bool              IsCustom(void)                               const { return (bool)this.GetProperty(SYMBOL_PROP_CUSTOM);                                }
   color             ColorBackground(void)                        const { return (color)this.GetProperty(SYMBOL_PROP_BACKGROUND_COLOR);                     }
   ENUM_SYMBOL_CHART_MODE ChartMode(void)                         const { return (ENUM_SYMBOL_CHART_MODE)this.GetProperty(SYMBOL_PROP_CHART_MODE);          }
   bool              IsExist(void)                                const { return (bool)this.GetProperty(SYMBOL_PROP_EXIST);                                 }
   bool              IsExist(const string name)                   const { return this.SymbolExists(name);                                                   }
   bool              IsSelect(void)                               const { return (bool)this.GetProperty(SYMBOL_PROP_SELECT);                                }
   bool              IsVisible(void)                              const { return (bool)this.GetProperty(SYMBOL_PROP_VISIBLE);                               }
   long              SessionDeals(void)                           const { return this.GetProperty(SYMBOL_PROP_SESSION_DEALS);                               }
   long              SessionBuyOrders(void)                       const { return this.GetProperty(SYMBOL_PROP_SESSION_BUY_ORDERS);                          }
   long              SessionSellOrders(void)                      const { return this.GetProperty(SYMBOL_PROP_SESSION_SELL_ORDERS);                         }
   long              Volume(void)                                 const { return this.GetProperty(SYMBOL_PROP_VOLUME);                                      }
   long              VolumeHigh(void)                             const { return this.GetProperty(SYMBOL_PROP_VOLUMEHIGH);                                  }
   long              VolumeLow(void)                              const { return this.GetProperty(SYMBOL_PROP_VOLUMELOW);                                   }
   long              Time(void)                                   const { return (datetime)this.GetProperty(SYMBOL_PROP_TIME);                              }
   int               Digits(void)                                 const { return (int)this.GetProperty(SYMBOL_PROP_DIGITS);                                 }
   int               DigitsLot(void)                              const { return (int)this.GetProperty(SYMBOL_PROP_DIGITS_LOTS);                            }
   int               Spread(void)                                 const { return (int)this.GetProperty(SYMBOL_PROP_SPREAD);                                 }
   bool              IsSpreadFloat(void)                          const { return (bool)this.GetProperty(SYMBOL_PROP_SPREAD_FLOAT);                          }
   int               TicksBookdepth(void)                         const { return (int)this.GetProperty(SYMBOL_PROP_TICKS_BOOKDEPTH);                        }
   bool              BookdepthSubscription(void)                  const { return (bool)this.GetProperty(SYMBOL_PROP_BOOKDEPTH_STATE);                       }
   ENUM_SYMBOL_CALC_MODE TradeCalcMode(void)                      const { return (ENUM_SYMBOL_CALC_MODE)this.GetProperty(SYMBOL_PROP_TRADE_CALC_MODE);      }
   ENUM_SYMBOL_TRADE_MODE TradeMode(void)                         const { return (ENUM_SYMBOL_TRADE_MODE)this.GetProperty(SYMBOL_PROP_TRADE_MODE);          }
   datetime          StartTime(void)                              const { return (datetime)this.GetProperty(SYMBOL_PROP_START_TIME);                        }
   datetime          ExpirationTime(void)                         const { return (datetime)this.GetProperty(SYMBOL_PROP_EXPIRATION_TIME);                   }
   int               TradeStopLevel(void)                         const { return (int)this.GetProperty(SYMBOL_PROP_TRADE_STOPS_LEVEL);                      }
   int               TradeFreezeLevel(void)                       const { return (int)this.GetProperty(SYMBOL_PROP_TRADE_FREEZE_LEVEL);                     }
   ENUM_SYMBOL_TRADE_EXECUTION TradeExecutionMode(void)           const { return (ENUM_SYMBOL_TRADE_EXECUTION)this.GetProperty(SYMBOL_PROP_TRADE_EXEMODE);  }
   ENUM_SYMBOL_SWAP_MODE SwapMode(void)                           const { return (ENUM_SYMBOL_SWAP_MODE)this.GetProperty(SYMBOL_PROP_SWAP_MODE);            }
   ENUM_DAY_OF_WEEK  SwapRollover3Days(void)                      const { return (ENUM_DAY_OF_WEEK)this.GetProperty(SYMBOL_PROP_SWAP_ROLLOVER3DAYS);        }
   bool              IsMarginHedgedUseLeg(void)                   const { return (bool)this.GetProperty(SYMBOL_PROP_MARGIN_HEDGED_USE_LEG);                 }
   int               ExpirationModeFlags(void)                    const { return (int)this.GetProperty(SYMBOL_PROP_EXPIRATION_MODE);                        }
   int               FillingModeFlags(void)                       const { return (int)this.GetProperty(SYMBOL_PROP_FILLING_MODE);                           }
   int               OrderModeFlags(void)                         const { return (int)this.GetProperty(SYMBOL_PROP_ORDER_MODE);                             }
   ENUM_SYMBOL_ORDER_GTC_MODE OrderModeGTC(void)                  const { return (ENUM_SYMBOL_ORDER_GTC_MODE)this.GetProperty(SYMBOL_PROP_ORDER_GTC_MODE);  }
   ENUM_SYMBOL_OPTION_MODE OptionMode(void)                       const { return (ENUM_SYMBOL_OPTION_MODE)this.GetProperty(SYMBOL_PROP_OPTION_MODE);        }
   ENUM_SYMBOL_OPTION_RIGHT OptionRight(void)                     const { return (ENUM_SYMBOL_OPTION_RIGHT)this.GetProperty(SYMBOL_PROP_OPTION_RIGHT);      }
//--- Real properties

No construtor da classe inicializamos o sinalizador de acompanhamento no estado false e escrevemos o valor deste sinalizador na propriedade do símbolo:

//+------------------------------------------------------------------+
//| Closed parametric constructor                                    |
//+------------------------------------------------------------------+
CSymbol::CSymbol(ENUM_SYMBOL_STATUS symbol_status,const string name,const int index)
  {
   this.m_name=name;
   this.m_book_subscribed=false;
   this.m_type=COLLECTION_SYMBOLS_ID;
   if(!this.Exist())
     {
      ::Print(DFUN_ERR_LINE,"\"",this.m_name,"\"",": ",CMessage::Text(MSG_LIB_SYS_NOT_SYMBOL_ON_SERVER));
      this.m_global_error=ERR_MARKET_UNKNOWN_SYMBOL;
     }
   bool select=::SymbolInfoInteger(this.m_name,SYMBOL_SELECT);
   ::ResetLastError();
   if(!select)
     {
      if(!this.SetToMarketWatch())
        {
         this.m_global_error=::GetLastError();
         ::Print(DFUN_ERR_LINE,"\"",this.m_name,"\": ",CMessage::Text(MSG_LIB_SYS_FAILED_PUT_SYMBOL),this.m_global_error);
        }
     }
   ::ResetLastError();
   if(!::SymbolInfoTick(this.m_name,this.m_tick))
     {
      this.m_global_error=::GetLastError();
      ::Print(DFUN_ERR_LINE,"\"",this.m_name,"\": ",CMessage::Text(MSG_LIB_SYS_NOT_GET_PRICE),this.m_global_error);
     }
//--- Initializing base object data arrays
   this.SetControlDataArraySizeLong(SYMBOL_PROP_INTEGER_TOTAL);
   this.SetControlDataArraySizeDouble(SYMBOL_PROP_DOUBLE_TOTAL);
   this.ResetChangesParams();
   this.ResetControlsParams();
   
//--- Initialize symbol data
   this.Reset();
   this.InitMarginRates();
#ifdef __MQL5__
   ::ResetLastError();
   if(!this.MarginRates())
     {
      this.m_global_error=::GetLastError();
      ::Print(DFUN_ERR_LINE,this.Name(),": ",CMessage::Text(MSG_LIB_SYS_NOT_GET_MARGIN_RATES),this.m_global_error);
      return;
     }
#endif 
   
//--- Save integer properties
   this.m_long_prop[SYMBOL_PROP_STATUS]                                             = symbol_status;
   this.m_long_prop[SYMBOL_PROP_INDEX_MW]                                           = index;
   this.m_long_prop[SYMBOL_PROP_VOLUME]                                             = (long)this.m_tick.volume;
   this.m_long_prop[SYMBOL_PROP_SELECT]                                             = ::SymbolInfoInteger(this.m_name,SYMBOL_SELECT);
   this.m_long_prop[SYMBOL_PROP_VISIBLE]                                            = ::SymbolInfoInteger(this.m_name,SYMBOL_VISIBLE);
   this.m_long_prop[SYMBOL_PROP_SESSION_DEALS]                                      = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_DEALS);
   this.m_long_prop[SYMBOL_PROP_SESSION_BUY_ORDERS]                                 = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_BUY_ORDERS);
   this.m_long_prop[SYMBOL_PROP_SESSION_SELL_ORDERS]                                = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_SELL_ORDERS);
   this.m_long_prop[SYMBOL_PROP_VOLUMEHIGH]                                         = ::SymbolInfoInteger(this.m_name,SYMBOL_VOLUMEHIGH);
   this.m_long_prop[SYMBOL_PROP_VOLUMELOW]                                          = ::SymbolInfoInteger(this.m_name,SYMBOL_VOLUMELOW);
   this.m_long_prop[SYMBOL_PROP_DIGITS]                                             = ::SymbolInfoInteger(this.m_name,SYMBOL_DIGITS);
   this.m_long_prop[SYMBOL_PROP_SPREAD]                                             = ::SymbolInfoInteger(this.m_name,SYMBOL_SPREAD);
   this.m_long_prop[SYMBOL_PROP_SPREAD_FLOAT]                                       = ::SymbolInfoInteger(this.m_name,SYMBOL_SPREAD_FLOAT);
   this.m_long_prop[SYMBOL_PROP_TICKS_BOOKDEPTH]                                    = ::SymbolInfoInteger(this.m_name,SYMBOL_TICKS_BOOKDEPTH);
   this.m_long_prop[SYMBOL_PROP_TRADE_MODE]                                         = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_MODE);
   this.m_long_prop[SYMBOL_PROP_START_TIME]                                         = ::SymbolInfoInteger(this.m_name,SYMBOL_START_TIME);
   this.m_long_prop[SYMBOL_PROP_EXPIRATION_TIME]                                    = ::SymbolInfoInteger(this.m_name,SYMBOL_EXPIRATION_TIME);
   this.m_long_prop[SYMBOL_PROP_TRADE_STOPS_LEVEL]                                  = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_STOPS_LEVEL);
   this.m_long_prop[SYMBOL_PROP_TRADE_FREEZE_LEVEL]                                 = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_FREEZE_LEVEL);
   this.m_long_prop[SYMBOL_PROP_TRADE_EXEMODE]                                      = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_EXEMODE);
   this.m_long_prop[SYMBOL_PROP_SWAP_ROLLOVER3DAYS]                                 = ::SymbolInfoInteger(this.m_name,SYMBOL_SWAP_ROLLOVER3DAYS);
   this.m_long_prop[SYMBOL_PROP_TIME]                                               = this.TickTime();
   this.m_long_prop[SYMBOL_PROP_EXIST]                                              = this.SymbolExists();
   this.m_long_prop[SYMBOL_PROP_CUSTOM]                                             = this.SymbolCustom();
   this.m_long_prop[SYMBOL_PROP_MARGIN_HEDGED_USE_LEG]                              = this.SymbolMarginHedgedUseLEG();
   this.m_long_prop[SYMBOL_PROP_ORDER_MODE]                                         = this.SymbolOrderMode();
   this.m_long_prop[SYMBOL_PROP_FILLING_MODE]                                       = this.SymbolOrderFillingMode();
   this.m_long_prop[SYMBOL_PROP_EXPIRATION_MODE]                                    = this.SymbolExpirationMode();
   this.m_long_prop[SYMBOL_PROP_ORDER_GTC_MODE]                                     = this.SymbolOrderGTCMode();
   this.m_long_prop[SYMBOL_PROP_OPTION_MODE]                                        = this.SymbolOptionMode();
   this.m_long_prop[SYMBOL_PROP_OPTION_RIGHT]                                       = this.SymbolOptionRight();
   this.m_long_prop[SYMBOL_PROP_BACKGROUND_COLOR]                                   = this.SymbolBackgroundColor();
   this.m_long_prop[SYMBOL_PROP_CHART_MODE]                                         = this.SymbolChartMode();
   this.m_long_prop[SYMBOL_PROP_TRADE_CALC_MODE]                                    = this.SymbolCalcMode();
   this.m_long_prop[SYMBOL_PROP_SWAP_MODE]                                          = this.SymbolSwapMode();
   this.m_long_prop[SYMBOL_PROP_BOOKDEPTH_STATE]                                    = this.m_book_subscribed;
//--- Save real properties
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_ASKHIGH)]                          = ::SymbolInfoDouble(this.m_name,SYMBOL_ASKHIGH);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_ASKLOW)]                           = ::SymbolInfoDouble(this.m_name,SYMBOL_ASKLOW);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_LASTHIGH)]                         = ::SymbolInfoDouble(this.m_name,SYMBOL_LASTHIGH);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_LASTLOW)]                          = ::SymbolInfoDouble(this.m_name,SYMBOL_LASTLOW);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_POINT)]                            = ::SymbolInfoDouble(this.m_name,SYMBOL_POINT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE_PROFIT)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE_PROFIT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE_LOSS)]            = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE_LOSS);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_SIZE)]                  = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_SIZE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_CONTRACT_SIZE)]              = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_CONTRACT_SIZE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_MIN)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_MIN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_MAX)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_MAX);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_STEP)]                      = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_STEP);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_LIMIT)]                     = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_LIMIT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SWAP_LONG)]                        = ::SymbolInfoDouble(this.m_name,SYMBOL_SWAP_LONG);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SWAP_SHORT)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_SWAP_SHORT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_INITIAL)]                   = ::SymbolInfoDouble(this.m_name,SYMBOL_MARGIN_INITIAL);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_MAINTENANCE)]               = ::SymbolInfoDouble(this.m_name,SYMBOL_MARGIN_MAINTENANCE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_VOLUME)]                   = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_TURNOVER)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_TURNOVER);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_INTEREST)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_INTEREST);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_BUY_ORDERS_VOLUME)]        = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_BUY_ORDERS_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_SELL_ORDERS_VOLUME)]       = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_SELL_ORDERS_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_OPEN)]                     = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_OPEN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_CLOSE)]                    = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_CLOSE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_AW)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_AW);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_SETTLEMENT)]         = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_SETTLEMENT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_LIMIT_MIN)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_LIMIT_MIN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_LIMIT_MAX)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_LIMIT_MAX);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_BID)]                              = this.m_tick.bid;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_ASK)]                              = this.m_tick.ask;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_LAST)]                             = this.m_tick.last;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_BIDHIGH)]                          = this.SymbolBidHigh();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_BIDLOW)]                           = this.SymbolBidLow();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_REAL)]                      = this.SymbolVolumeReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUMEHIGH_REAL)]                  = this.SymbolVolumeHighReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUMELOW_REAL)]                   = this.SymbolVolumeLowReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_OPTION_STRIKE)]                    = this.SymbolOptionStrike();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_ACCRUED_INTEREST)]           = this.SymbolTradeAccruedInterest();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_FACE_VALUE)]                 = this.SymbolTradeFaceValue();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_LIQUIDITY_RATE)]             = this.SymbolTradeLiquidityRate();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_HEDGED)]                    = this.SymbolMarginHedged();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_LONG_INITIAL)]              = this.m_margin_rate.Long.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOP_INITIAL)]          = this.m_margin_rate.BuyStop.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_LIMIT_INITIAL)]         = this.m_margin_rate.BuyLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOPLIMIT_INITIAL)]     = this.m_margin_rate.BuyStopLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_LONG_MAINTENANCE)]          = this.m_margin_rate.Long.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOP_MAINTENANCE)]      = this.m_margin_rate.BuyStop.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_LIMIT_MAINTENANCE)]     = this.m_margin_rate.BuyLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOPLIMIT_MAINTENANCE)] = this.m_margin_rate.BuyStopLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SHORT_INITIAL)]             = this.m_margin_rate.Short.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOP_INITIAL)]         = this.m_margin_rate.SellStop.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_LIMIT_INITIAL)]        = this.m_margin_rate.SellLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOPLIMIT_INITIAL)]    = this.m_margin_rate.SellStopLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SHORT_MAINTENANCE)]         = this.m_margin_rate.Short.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOP_MAINTENANCE)]     = this.m_margin_rate.SellStop.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_LIMIT_MAINTENANCE)]    = this.m_margin_rate.SellLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOPLIMIT_MAINTENANCE)]= this.m_margin_rate.SellStopLimit.Maintenance;
//--- Save string properties
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_NAME)]                             = this.m_name;
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_CURRENCY_BASE)]                    = ::SymbolInfoString(this.m_name,SYMBOL_CURRENCY_BASE);
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_CURRENCY_PROFIT)]                  = ::SymbolInfoString(this.m_name,SYMBOL_CURRENCY_PROFIT);
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_CURRENCY_MARGIN)]                  = ::SymbolInfoString(this.m_name,SYMBOL_CURRENCY_MARGIN);
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_DESCRIPTION)]                      = ::SymbolInfoString(this.m_name,SYMBOL_DESCRIPTION);
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_PATH)]                             = ::SymbolInfoString(this.m_name,SYMBOL_PATH);
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_BASIS)]                            = this.SymbolBasis();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_BANK)]                             = this.SymbolBank();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_ISIN)]                             = this.SymbolISIN();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_FORMULA)]                          = this.SymbolFormula();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_PAGE)]                             = this.SymbolPage();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_CATEGORY)]                         = this.SymbolCategory();
   this.m_string_prop[this.IndexProp(SYMBOL_PROP_EXCHANGE)]                         = this.SymbolExchange();
//--- Save additional integer properties
   this.m_long_prop[SYMBOL_PROP_DIGITS_LOTS]                                        = this.SymbolDigitsLot();
   
//--- Fill in the symbol current data
   for(int i=0;i<SYMBOL_PROP_INTEGER_TOTAL;i++)
      this.m_long_prop_event[i][3]=this.m_long_prop[i];
   for(int i=0;i<SYMBOL_PROP_DOUBLE_TOTAL;i++)
      this.m_double_prop_event[i][3]=this.m_double_prop[i];
   
//--- Update the base object data and search for changes
   CBaseObjExt::Refresh();
//---
   if(!select)
      this.RemoveFromMarketWatch();

//--- Initializing default values of a trading object
   this.m_trade.Init(this.Name(),0,this.LotsMin(),5,0,0,false,this.GetCorrectTypeFilling(),this.GetCorrectTypeExpiration(),LOG_LEVEL_ERROR_MSG);
  }
//+------------------------------------------------------------------+

Implementação do destruidor de classe:

//+------------------------------------------------------------------+
//| Destructor                                                       |
//+------------------------------------------------------------------+
CSymbol::~CSymbol(void)
  {
   if(this.m_book_subscribed)
      this.BookClose();
  }
//+------------------------------------------------------------------+

Se o sinalizador de acompanhamento do livro de ofertas estiver definido, vamos desabilitá-lo.

Assim, para qualquer símbolo, será observada a regra 1 acompanhamento = remoção de acompanhamento. Visto que para cada um dos símbolos usados no programa e para os quais foi ativado o acompanhamento, no final do programa, o método para cancelar o acompanhamento do livro de ofertas será chamado no destruidor de classe apenas se um acompanhamento tiver sido ativado para o símbolo.

No método que retorna uma descrição da propriedade inteira de um símbolo, adicionamos um bloco de código para exibir uma descrição da propriedade de acompanhamento do livro de ofertas:

//+------------------------------------------------------------------+
//| Return the description of the symbol integer property            |
//+------------------------------------------------------------------+
string CSymbol::GetPropertyDescription(ENUM_SYMBOL_PROP_INTEGER property)
  {
   return
     (
      property==SYMBOL_PROP_STATUS              ?  CMessage::Text(MSG_ORD_STATUS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetStatusDescription()
         )  :
      property==SYMBOL_PROP_INDEX_MW            ?  CMessage::Text(MSG_SYM_PROP_INDEX)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_CUSTOM              ?  CMessage::Text(MSG_SYM_PROP_CUSTOM)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO))
         )  :
      property==SYMBOL_PROP_CHART_MODE          ?  CMessage::Text(MSG_SYM_PROP_CHART_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetChartModeDescription()
         )  :
      property==SYMBOL_PROP_EXIST               ?  CMessage::Text(MSG_SYM_PROP_EXIST)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO))
         )  :
      property==SYMBOL_PROP_SELECT  ?  CMessage::Text(MSG_SYM_PROP_SELECT)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO))
         )  :
      property==SYMBOL_PROP_VISIBLE ?  CMessage::Text(MSG_SYM_PROP_VISIBLE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO))
         )  :
      property==SYMBOL_PROP_SESSION_DEALS       ?  CMessage::Text(MSG_SYM_PROP_SESSION_DEALS)+
         (!this.SupportProperty(property)    ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_SESSION_BUY_ORDERS  ?  CMessage::Text(MSG_SYM_PROP_SESSION_BUY_ORDERS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_SESSION_SELL_ORDERS ?  CMessage::Text(MSG_SYM_PROP_SESSION_SELL_ORDERS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_VOLUME              ?  CMessage::Text(MSG_SYM_PROP_VOLUME)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_VOLUMEHIGH          ?  CMessage::Text(MSG_SYM_PROP_VOLUMEHIGH)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_VOLUMELOW           ?  CMessage::Text(MSG_SYM_PROP_VOLUMELOW)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_TIME                ?  CMessage::Text(MSG_SYM_PROP_TIME)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)==0 ? "("+CMessage::Text(MSG_LIB_SYS_NO_TICKS_YET)+")" : TimeMSCtoString(this.GetProperty(property)))
         )  :
      property==SYMBOL_PROP_DIGITS              ?  CMessage::Text(MSG_SYM_PROP_DIGITS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_DIGITS_LOTS         ?  CMessage::Text(MSG_SYM_PROP_DIGITS_LOTS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_SPREAD              ?  CMessage::Text(MSG_SYM_PROP_SPREAD)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_SPREAD_FLOAT        ?  CMessage::Text(MSG_SYM_PROP_SPREAD_FLOAT)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_YES))
         )  :
      property==SYMBOL_PROP_TICKS_BOOKDEPTH     ?  CMessage::Text(MSG_SYM_PROP_TICKS_BOOKDEPTH)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__(string)this.GetProperty(property) #else CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      property==SYMBOL_PROP_BOOKDEPTH_STATE     ?  CMessage::Text(MSG_SYM_SYMBOLS_MODE_BOOK)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+ #ifdef __MQL5__
                  (this.GetProperty(property) ? CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO)) 
                #else 
                  CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) 
                #endif 
         )  :
      property==SYMBOL_PROP_TRADE_CALC_MODE     ?  CMessage::Text(MSG_SYM_PROP_TRADE_CALC_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetCalcModeDescription()
         )  :
      property==SYMBOL_PROP_TRADE_MODE ?  CMessage::Text(MSG_SYM_PROP_TRADE_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetTradeModeDescription()
         )  :
      property==SYMBOL_PROP_START_TIME          ?  CMessage::Text(MSG_SYM_PROP_START_TIME)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
         (this.GetProperty(property)==0  ?  ": ("+CMessage::Text(MSG_LIB_PROP_EMPTY)+")" : ": "+TimeMSCtoString(this.GetProperty(property)*1000))
         )  :
      property==SYMBOL_PROP_EXPIRATION_TIME     ?  CMessage::Text(MSG_SYM_PROP_EXPIRATION_TIME)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
         (this.GetProperty(property)==0  ?  ": ("+CMessage::Text(MSG_LIB_PROP_EMPTY)+")" : ": "+TimeMSCtoString(this.GetProperty(property)*1000))
         )  :
      property==SYMBOL_PROP_TRADE_STOPS_LEVEL   ?  CMessage::Text(MSG_SYM_PROP_TRADE_STOPS_LEVEL)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_TRADE_FREEZE_LEVEL  ?  CMessage::Text(MSG_SYM_PROP_TRADE_FREEZE_LEVEL)+
         (!this.SupportProperty(property)    ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+(string)this.GetProperty(property)
         )  :
      property==SYMBOL_PROP_TRADE_EXEMODE       ?  CMessage::Text(MSG_SYM_PROP_TRADE_EXEMODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetTradeExecDescription()
         )  :
      property==SYMBOL_PROP_SWAP_MODE           ?  CMessage::Text(MSG_SYM_PROP_SWAP_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetSwapModeDescription()
         )  :
      property==SYMBOL_PROP_SWAP_ROLLOVER3DAYS  ?  CMessage::Text(MSG_SYM_PROP_SWAP_ROLLOVER3DAYS)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+DayOfWeekDescription(this.SwapRollover3Days())
         )  :
      property==SYMBOL_PROP_MARGIN_HEDGED_USE_LEG  ?  CMessage::Text(MSG_SYM_PROP_MARGIN_HEDGED_USE_LEG)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED)   :
          ": "+(this.GetProperty(property)   ?  CMessage::Text(MSG_LIB_TEXT_YES) : CMessage::Text(MSG_LIB_TEXT_NO))
         )  :
      property==SYMBOL_PROP_EXPIRATION_MODE     ?  CMessage::Text(MSG_SYM_PROP_EXPIRATION_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetExpirationModeFlagsDescription()
         )  :
      property==SYMBOL_PROP_FILLING_MODE        ?  CMessage::Text(MSG_SYM_PROP_FILLING_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetFillingModeFlagsDescription()
         )  :
      property==SYMBOL_PROP_ORDER_MODE          ?  CMessage::Text(MSG_SYM_PROP_ORDER_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetOrderModeFlagsDescription()
         )  :
      property==SYMBOL_PROP_ORDER_GTC_MODE      ?  CMessage::Text(MSG_SYM_PROP_ORDER_GTC_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetOrderGTCModeDescription()
         )  :
      property==SYMBOL_PROP_OPTION_MODE         ?  CMessage::Text(MSG_SYM_PROP_OPTION_MODE)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetOptionTypeDescription()
         )  :
      property==SYMBOL_PROP_OPTION_RIGHT        ?  CMessage::Text(MSG_SYM_PROP_OPTION_RIGHT)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
          ": "+this.GetOptionRightDescription()
         )  :
      property==SYMBOL_PROP_BACKGROUND_COLOR    ?  CMessage::Text(MSG_SYM_PROP_BACKGROUND_COLOR)+
         (!this.SupportProperty(property) ?  ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED) :
         #ifdef __MQL5__
         (this.GetProperty(property)==CLR_DEFAULT || this.GetProperty(property)==CLR_NONE ?  ": ("+CMessage::Text(MSG_LIB_PROP_EMPTY)+")" : ": "+::ColorToString((color)this.GetProperty(property),true))
         #else ": "+CMessage::Text(MSG_LIB_PROP_NOT_SUPPORTED_MQL4) #endif 
         )  :
      ""
     );
  }
//+------------------------------------------------------------------+

Método de acompanhamento do livro de ofertas:

//+------------------------------------------------------------------+
//| Subscribe to the Depth of Market                                 |
//+------------------------------------------------------------------+
bool CSymbol::BookAdd(void)
  {
   this.m_book_subscribed=(#ifdef __MQL5__ ::MarketBookAdd(this.m_name) #else false #endif);
   if(this.m_book_subscribed)
     {
      this.m_long_prop[SYMBOL_PROP_BOOKDEPTH_STATE]=this.m_book_subscribed;
      ::Print(CMessage::Text(MSG_SYM_SYMBOLS_BOOK_ADD)+" "+this.m_name);
     }
   return this.m_book_subscribed;
  }
//+------------------------------------------------------------------+

Escrevemos na variável m_book_subscribed, que armazena o sinalizador de status de acompanhamento (subscrição), o resultado da função MarketBookAdd() que garante a abertura do livro de ofertas para o instrumento especificado e ativa o acompanhamento de alterações neste último.
Se o acompanhamento for realizado, exibimos uma mensagem sobre o sucesso disso.
O método retorna o resultado escrito em m_book_subscribed.

Método para fechar o livro de ofertas:

//+------------------------------------------------------------------+
//| Close the market depth                                           |
//+------------------------------------------------------------------+
bool CSymbol::BookClose(void)
  {
//--- If the DOM subscription flag is off, subscription is disabled (or not enabled yet). Return 'true'
   if(!this.m_book_subscribed)
      return true;
//--- Save the result of unsubscribing from the DOM
   bool res=( #ifdef __MQL5__ ::MarketBookRelease(this.m_name) #else true #endif );
//--- If unsubscribed successfully, reset the DOM subscription flag and write the status to the object property
   if(res)
     {
      this.m_long_prop[SYMBOL_PROP_BOOKDEPTH_STATE]=this.m_book_subscribed=false;
      ::Print(CMessage::Text(MSG_SYM_SYMBOLS_BOOK_DEL)+" "+this.m_name);
     }
//--- Return the result of unsubscribing from DOM
   return res;
  }
//+------------------------------------------------------------------+

A lógica do método é descrita nos comentários no código. Quero esclarecer que o método deve retornar o sinalizador de cancelamento de acompanhamento da transmissão de dados do livro de ofertas. Se você ainda não estabeleceu o acompanhamento, o método retorna imediatamente true, o que indica um cancelamento bem-sucedido do acompanhamento da transmissão de dados do livro de ofertas, embora na verdade não houvesse nenhum acompanhamento.

No método para atualizar todas as propriedades do símbolo, escrevemos a atualização do estado do acompanhamento correspondendo ao estado do sinalizador na variável m_book_subscribed:

//+------------------------------------------------------------------+
//| Update all symbol data                                           |
//+------------------------------------------------------------------+
void CSymbol::Refresh(void)
  {
//--- Update quote data
   if(!this.RefreshRates())
      return;
#ifdef __MQL5__
   ::ResetLastError();
   if(!this.MarginRates())
     {
      this.m_global_error=::GetLastError();
      return;
     }
#endif 
//--- Initialize event data
   this.m_is_event=false;
   this.m_hash_sum=0;
//--- Update integer properties
   this.m_long_prop[SYMBOL_PROP_SELECT]                                             = ::SymbolInfoInteger(this.m_name,SYMBOL_SELECT);
   this.m_long_prop[SYMBOL_PROP_VISIBLE]                                            = ::SymbolInfoInteger(this.m_name,SYMBOL_VISIBLE);
   this.m_long_prop[SYMBOL_PROP_SESSION_DEALS]                                      = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_DEALS);
   this.m_long_prop[SYMBOL_PROP_SESSION_BUY_ORDERS]                                 = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_BUY_ORDERS);
   this.m_long_prop[SYMBOL_PROP_SESSION_SELL_ORDERS]                                = ::SymbolInfoInteger(this.m_name,SYMBOL_SESSION_SELL_ORDERS);
   this.m_long_prop[SYMBOL_PROP_VOLUMEHIGH]                                         = ::SymbolInfoInteger(this.m_name,SYMBOL_VOLUMEHIGH);
   this.m_long_prop[SYMBOL_PROP_VOLUMELOW]                                          = ::SymbolInfoInteger(this.m_name,SYMBOL_VOLUMELOW);
   this.m_long_prop[SYMBOL_PROP_SPREAD]                                             = ::SymbolInfoInteger(this.m_name,SYMBOL_SPREAD);
   this.m_long_prop[SYMBOL_PROP_TICKS_BOOKDEPTH]                                    = ::SymbolInfoInteger(this.m_name,SYMBOL_TICKS_BOOKDEPTH);
   this.m_long_prop[SYMBOL_PROP_START_TIME]                                         = ::SymbolInfoInteger(this.m_name,SYMBOL_START_TIME);
   this.m_long_prop[SYMBOL_PROP_EXPIRATION_TIME]                                    = ::SymbolInfoInteger(this.m_name,SYMBOL_EXPIRATION_TIME);
   this.m_long_prop[SYMBOL_PROP_TRADE_STOPS_LEVEL]                                  = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_STOPS_LEVEL);
   this.m_long_prop[SYMBOL_PROP_TRADE_FREEZE_LEVEL]                                 = ::SymbolInfoInteger(this.m_name,SYMBOL_TRADE_FREEZE_LEVEL);
   this.m_long_prop[SYMBOL_PROP_BACKGROUND_COLOR]                                   = this.SymbolBackgroundColor();
   this.m_long_prop[SYMBOL_PROP_BOOKDEPTH_STATE]                                    = this.m_book_subscribed;
   
//--- Update real properties
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE_PROFIT)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE_PROFIT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_VALUE_LOSS)]            = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_VALUE_LOSS);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_TICK_SIZE)]                  = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_TICK_SIZE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_CONTRACT_SIZE)]              = ::SymbolInfoDouble(this.m_name,SYMBOL_TRADE_CONTRACT_SIZE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_MIN)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_MIN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_MAX)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_MAX);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_STEP)]                      = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_STEP);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_LIMIT)]                     = ::SymbolInfoDouble(this.m_name,SYMBOL_VOLUME_LIMIT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SWAP_LONG)]                        = ::SymbolInfoDouble(this.m_name,SYMBOL_SWAP_LONG);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SWAP_SHORT)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_SWAP_SHORT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_INITIAL)]                   = ::SymbolInfoDouble(this.m_name,SYMBOL_MARGIN_INITIAL);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_MAINTENANCE)]               = ::SymbolInfoDouble(this.m_name,SYMBOL_MARGIN_MAINTENANCE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_VOLUME)]                   = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_TURNOVER)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_TURNOVER);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_INTEREST)]                 = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_INTEREST);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_BUY_ORDERS_VOLUME)]        = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_BUY_ORDERS_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_SELL_ORDERS_VOLUME)]       = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_SELL_ORDERS_VOLUME);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_OPEN)]                     = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_OPEN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_CLOSE)]                    = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_CLOSE);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_AW)]                       = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_AW);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_SETTLEMENT)]         = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_SETTLEMENT);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_LIMIT_MIN)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_LIMIT_MIN);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_SESSION_PRICE_LIMIT_MAX)]          = ::SymbolInfoDouble(this.m_name,SYMBOL_SESSION_PRICE_LIMIT_MAX);
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUME_REAL)]                      = this.SymbolVolumeReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUMEHIGH_REAL)]                  = this.SymbolVolumeHighReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_VOLUMELOW_REAL)]                   = this.SymbolVolumeLowReal();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_OPTION_STRIKE)]                    = this.SymbolOptionStrike();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_ACCRUED_INTEREST)]           = this.SymbolTradeAccruedInterest();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_FACE_VALUE)]                 = this.SymbolTradeFaceValue();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_TRADE_LIQUIDITY_RATE)]             = this.SymbolTradeLiquidityRate();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_HEDGED)]                    = this.SymbolMarginHedged();
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_LONG_INITIAL)]              = this.m_margin_rate.Long.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOP_INITIAL)]          = this.m_margin_rate.BuyStop.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_LIMIT_INITIAL)]         = this.m_margin_rate.BuyLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOPLIMIT_INITIAL)]     = this.m_margin_rate.BuyStopLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_LONG_MAINTENANCE)]          = this.m_margin_rate.Long.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOP_MAINTENANCE)]      = this.m_margin_rate.BuyStop.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_LIMIT_MAINTENANCE)]     = this.m_margin_rate.BuyLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_BUY_STOPLIMIT_MAINTENANCE)] = this.m_margin_rate.BuyStopLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SHORT_INITIAL)]             = this.m_margin_rate.Short.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOP_INITIAL)]         = this.m_margin_rate.SellStop.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_LIMIT_INITIAL)]        = this.m_margin_rate.SellLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOPLIMIT_INITIAL)]    = this.m_margin_rate.SellStopLimit.Initial;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SHORT_MAINTENANCE)]         = this.m_margin_rate.Short.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOP_MAINTENANCE)]     = this.m_margin_rate.SellStop.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_LIMIT_MAINTENANCE)]    = this.m_margin_rate.SellLimit.Maintenance;
   this.m_double_prop[this.IndexProp(SYMBOL_PROP_MARGIN_SELL_STOPLIMIT_MAINTENANCE)]= this.m_margin_rate.SellStopLimit.Maintenance;
   
//--- Fill in the symbol current data
   for(int i=0;i<SYMBOL_PROP_INTEGER_TOTAL;i++)
      this.m_long_prop_event[i][3]=this.m_long_prop[i];
   for(int i=0;i<SYMBOL_PROP_DOUBLE_TOTAL;i++)
      this.m_double_prop_event[i][3]=this.m_double_prop[i];
   
//--- Update the base object data and search for changes
   CBaseObjExt::Refresh();
   this.CheckEvents();
  }
//+------------------------------------------------------------------+

Estas são todas mudanças na classe do objeto-símbolo para em artigos futuros conseguirmos trabalhar com o acompanhamento da transmissão de dados do livro de ofertas.


Teste

Para o teste, vamos pegar o Expert Advisor do artigo anterior e salvá-lo numa nova pasta \MQL5\Experts\TestDoEasy\Part62\ com o novo nome TestDoEasyPart62.mq5.

No teste, vamos optar por trabalhar apenas com os símbolos especificados nas configurações (dois símbolos). Vamos adicionar às configurações um parâmetro indicando o sinalizador de uso de acompanhamento do livro de ofertas para todos os símbolos selecionados e ver como funciona isto, como os dados da série de ticks são atualizados, bem como de que forma novos objetos de dados de ticks são adicionados e o tamanho de suas listas é controlado de acordo com um determinado valor máximo possível.

No escopo de variáveis de entrada adicionamos um novo parâmetro de entrada que permite escolher se desejamos assinar o livro de ofertas para os símbolos selecionados do Expert Advisor:

//--- input variables
input    ushort            InpMagic             =  123;  // Magic number
input    double            InpLots              =  0.1;  // Lots
input    uint              InpStopLoss          =  150;  // StopLoss in points
input    uint              InpTakeProfit        =  150;  // TakeProfit in points
input    uint              InpDistance          =  50;   // Pending orders distance (points)
input    uint              InpDistanceSL        =  50;   // StopLimit orders distance (points)
input    uint              InpDistancePReq      =  50;   // Distance for Pending Request's activate (points)
input    uint              InpBarsDelayPReq     =  5;    // Bars delay for Pending Request's activate (current timeframe)
input    uint              InpSlippage          =  5;    // Slippage in points
input    uint              InpSpreadMultiplier  =  1;    // Spread multiplier for adjusting stop-orders by StopLevel
input    uchar             InpTotalAttempts     =  5;    // Number of trading attempts
sinput   double            InpWithdrawal        =  10;   // Withdrawal funds (in tester)
sinput   uint              InpButtShiftX        =  0;    // Buttons X shift 
sinput   uint              InpButtShiftY        =  10;   // Buttons Y shift 
input    uint              InpTrailingStop      =  50;   // Trailing Stop (points)
input    uint              InpTrailingStep      =  20;   // Trailing Step (points)
input    uint              InpTrailingStart     =  0;    // Trailing Start (points)
input    uint              InpStopLossModify    =  20;   // StopLoss for modification (points)
input    uint              InpTakeProfitModify  =  60;   // TakeProfit for modification (points)
sinput   ENUM_SYMBOLS_MODE InpModeUsedSymbols   =  SYMBOLS_MODE_CURRENT;            // Mode of used symbols list
sinput   string            InpUsedSymbols       =  "EURUSD,AUDUSD,EURAUD,EURCAD,EURGBP,EURJPY,EURUSD,GBPUSD,NZDUSD,USDCAD,USDJPY";  // List of used symbols (comma - separator)
sinput   ENUM_INPUT_YES_NO InpUseBook           =  INPUT_YES;                       // Use Depth of Market
sinput   ENUM_TIMEFRAMES_MODE InpModeUsedTFs    =  TIMEFRAMES_MODE_LIST;            // Mode of used timeframes list
sinput   string            InpUsedTFs           =  "M1,M5,M15,M30,H1,H4,D1,W1,MN1"; // List of used timeframes (comma - separator)
sinput   bool              InpUseSounds         =  true; // Use sounds

Na função de inicialização da biblioteca OnInitDoEasy() na área de configuração de valores de controle para símbolos adicionamos um bloco de código para acompanhamento da transmissão de dados do livro de ofertas para cada um dos símbolos de trabalho, e para o símbolo atual, além disso, iremos imprimir todas as suas propriedades no log - para verificar a nova propriedade do símbolo que adicionamos hoje.

//+------------------------------------------------------------------+
//| Initializing DoEasy library                                      |
//+------------------------------------------------------------------+
void OnInitDoEasy()
  {
//--- Check if working with the full list is selected
   used_symbols_mode=InpModeUsedSymbols;
   if((ENUM_SYMBOLS_MODE)used_symbols_mode==SYMBOLS_MODE_ALL)
     {
      int total=SymbolsTotal(false);
      string ru_n="\nКоличество символов на сервере "+(string)total+".\nМаксимальное количество: "+(string)SYMBOLS_COMMON_TOTAL+" символов.";
      string en_n="\nNumber of symbols on server "+(string)total+".\nMaximum number: "+(string)SYMBOLS_COMMON_TOTAL+" symbols.";
      string caption=TextByLanguage("Внимание!","Attention!");
      string ru="Выбран режим работы с полным списком.\nВ этом режиме первичная подготовка списков коллекций символов и таймсерий может занять длительное время."+ru_n+"\nПродолжить?\n\"Нет\" - работа с текущим символом \""+Symbol()+"\"";
      string en="Full list mode selected.\nIn this mode, the initial preparation of lists of symbol collections and timeseries can take a long time."+en_n+"\nContinue?\n\"No\" - working with the current symbol \""+Symbol()+"\"";
      string message=TextByLanguage(ru,en);
      int flags=(MB_YESNO | MB_ICONWARNING | MB_DEFBUTTON2);
      int mb_res=MessageBox(message,caption,flags);
      switch(mb_res)
        {
         case IDNO : 
           used_symbols_mode=SYMBOLS_MODE_CURRENT; 
           break;
         default:
           break;
        }
     }
//--- Set the counter start point to measure the approximate library initialization time
   ulong begin=GetTickCount();
   Print(TextByLanguage("--- Инициализация библиотеки \"DoEasy\" ---","--- Initializing the \"DoEasy\" library ---"));
//--- Fill in the array of used symbols
   CreateUsedSymbolsArray((ENUM_SYMBOLS_MODE)used_symbols_mode,InpUsedSymbols,array_used_symbols);
//--- Set the type of the used symbol list in the symbol collection and fill in the list of symbol timeseries
   engine.SetUsedSymbols(array_used_symbols);
//--- Displaying the selected mode of working with the symbol object collection in the journal
   string num=
     (
      used_symbols_mode==SYMBOLS_MODE_CURRENT ? ": \""+Symbol()+"\"" : 
      TextByLanguage(". Количество используемых символов: ",". The number of symbols used: ")+(string)engine.GetSymbolsCollectionTotal()
     );
   Print(engine.ModeSymbolsListDescription(),num);
//--- Implement displaying the list of used symbols only for MQL5 - MQL4 has no ArrayPrint() function
#ifdef __MQL5__
   if(InpModeUsedSymbols!=SYMBOLS_MODE_CURRENT)
     {
      string array_symbols[];
      CArrayObj* list_symbols=engine.GetListAllUsedSymbols();
      for(int i=0;i<list_symbols.Total();i++)
        {
         CSymbol *symbol=list_symbols.At(i);
         if(symbol==NULL)
            continue;
         ArrayResize(array_symbols,ArraySize(array_symbols)+1,SYMBOLS_COMMON_TOTAL);
         array_symbols[ArraySize(array_symbols)-1]=symbol.Name();
        }
      ArrayPrint(array_symbols);
     }
#endif   
//--- Set used timeframes
   CreateUsedTimeframesArray(InpModeUsedTFs,InpUsedTFs,array_used_periods);
//--- Display the selected mode of working with the timeseries object collection
   string mode=
     (
      InpModeUsedTFs==TIMEFRAMES_MODE_CURRENT   ? 
         TextByLanguage("Работа только с текущим таймфреймом: ","Work only with the current Period: ")+TimeframeDescription((ENUM_TIMEFRAMES)Period())   :
      InpModeUsedTFs==TIMEFRAMES_MODE_LIST      ? 
         TextByLanguage("Работа с заданным списком таймфреймов:","Work with a predefined list of Periods:")                                              :
      TextByLanguage("Работа с полным списком таймфреймов:","Work with the full list of all Periods:")
     );
   Print(mode);
//--- Implement displaying the list of used timeframes only for MQL5 - MQL4 has no ArrayPrint() function
#ifdef __MQL5__
   if(InpModeUsedTFs!=TIMEFRAMES_MODE_CURRENT)
      ArrayPrint(array_used_periods);
#endif 
//--- Create timeseries of all used symbols
   engine.SeriesCreateAll(array_used_periods);

//--- Check created timeseries - display descriptions of all created timeseries in the journal
//--- (true - only created ones, false - created and declared ones)
   engine.GetTimeSeriesCollection().PrintShort(false); // Short descriptions
   //engine.GetTimeSeriesCollection().Print(true);      // Full descriptions

//--- Create tick series of all used symbols
   engine.GetTickSeriesCollection().CreateTickSeriesAll();
//--- Check created tick series - display descriptions of all created tick series in the journal
   engine.GetTickSeriesCollection().Print();

//--- Create resource text files
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_01",TextByLanguage("Звук упавшей монетки 1","Falling coin 1"),sound_array_coin_01);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_02",TextByLanguage("Звук упавших монеток","Falling coins"),sound_array_coin_02);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_03",TextByLanguage("Звук монеток","Coins"),sound_array_coin_03);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_04",TextByLanguage("Звук упавшей монетки 2","Falling coin 2"),sound_array_coin_04);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_01",TextByLanguage("Звук щелчка по кнопке 1","Button click 1"),sound_array_click_01);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_02",TextByLanguage("Звук щелчка по кнопке 2","Button click 2"),sound_array_click_02);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_03",TextByLanguage("Звук щелчка по кнопке 3","Button click 3"),sound_array_click_03);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_cash_machine_01",TextByLanguage("Звук кассового аппарата","Cash machine"),sound_array_cash_machine_01);
   engine.CreateFile(FILE_TYPE_BMP,"img_array_spot_green",TextByLanguage("Изображение \"Зелёный светодиод\"","Image \"Green Spot lamp\""),img_array_spot_green);
   engine.CreateFile(FILE_TYPE_BMP,"img_array_spot_red",TextByLanguage("Изображение \"Красный светодиод\"","Image \"Red Spot lamp\""),img_array_spot_red);

//--- Pass all existing collections to the main library class
   engine.CollectionOnInit();

//--- Set the default magic number for all used symbols
   engine.TradingSetMagic(engine.SetCompositeMagicNumber(magic_number));
//--- Set synchronous passing of orders for all used symbols
   engine.TradingSetAsyncMode(false);
//--- Set the number of trading attempts in case of an error
   engine.TradingSetTotalTry(InpTotalAttempts);
//--- Set correct order expiration and filling types to all trading objects
   engine.TradingSetCorrectTypeExpiration();
   engine.TradingSetCorrectTypeFilling();

//--- Set standard sounds for trading objects of all used symbols
   engine.SetSoundsStandart();
//--- Set the general flag of using sounds
   engine.SetUseSounds(InpUseSounds);
//--- Set the spread multiplier for symbol trading objects in the symbol collection
   engine.SetSpreadMultiplier(InpSpreadMultiplier);
      
//--- Set controlled values for symbols
   //--- Get the list of all collection symbols
   CArrayObj *list=engine.GetListAllUsedSymbols();
   if(list!=NULL && list.Total()!=0)
     {
      //--- In a loop by the list, set the necessary values for tracked symbol properties
      //--- By default, the LONG_MAX value is set to all properties, which means "Do not track this property" 
      //--- It can be enabled or disabled (by setting the value less than LONG_MAX or vice versa - set the LONG_MAX value) at any time and anywhere in the program

      for(int i=0;i<list.Total();i++)
        {
         CSymbol* symbol=list.At(i);
         if(symbol==NULL)
            continue;
         if(InpUseBook)
            symbol.BookAdd();
         if(symbol.Name()==Symbol())
            symbol.Print();
         /*
         //--- Set control of the symbol price increase by 100 points
         symbol.SetControlBidInc(100000*symbol.Point());
         //--- Set control of the symbol price decrease by 100 points
         symbol.SetControlBidDec(100000*symbol.Point());
         //--- Set control of the symbol spread increase by 40 points
         symbol.SetControlSpreadInc(400);
         //--- Set control of the symbol spread decrease by 40 points
         symbol.SetControlSpreadDec(400);
         //--- Set control of the current spread by the value of 40 points
         symbol.SetControlSpreadLevel(400);
         */
        }

     }
//--- Set controlled values for the current account
   CAccount* account=engine.GetAccountCurrent();
   if(account!=NULL)
     {
      //--- Set control of the profit increase to 10
      account.SetControlledValueINC(ACCOUNT_PROP_PROFIT,10.0);
      //--- Set control of the funds increase to 15
      account.SetControlledValueINC(ACCOUNT_PROP_EQUITY,15.0);
      //--- Set profit control level to 20
      account.SetControlledValueLEVEL(ACCOUNT_PROP_PROFIT,20.0);
     }
     
//--- Get the end of the library initialization time counting and display it in the journal
   ulong end=GetTickCount();
   Print(TextByLanguage("Время инициализации библиотеки: ","Library initialization time: "),TimeMSCtoString(end-begin,TIME_MINUTES|TIME_SECONDS));
  }
//+------------------------------------------------------------------+

Vamos compilar o Expert Advisor, iniciá-lo no gráfico do símbolo EURUSD, tendo previamente selecionado nas configurações o uso de dois símbolos da lista - EURUSD e AUDUSD, e a necessidade de acompanhamento da transmissão de dados dos livros de ofertas de todos os símbolos selecionados:


Após iniciar o EA, o log mostrará mensagens sobre a ativação do acompanhamento da transmissão de dados do livro de ofertas de dois símbolos, e então todas as propriedades do símbolo EURUSD são exibidas, onde houver uma sequência de uma nova propriedade sobre o status do acompanhamento do livro de ofertas:

Account 8550475: Artyom Trishkin (MetaQuotes Software Corp.) 10426.13 USD, 1:100, Hedge, MetaTrader 5 demo
--- Initializing "DoEasy" library ---
Working with predefined symbol list. The number of used symbols: 2
"AUDUSD" "EURUSD"
Working with the current timeframe only: H1
AUDUSD symbol timeseries: 
- Timeseries "AUDUSD" H1: Requested: 1000, Actual: 1000, Created: 1000, On the server: 6325
EURUSD symbol timeseries: 
- Timeseries "EURUSD" H1: Requested: 1000, Actual: 1000, Created: 1000, On the server: 5806
Tick series "AUDUSD": Requested number of days: 1, Historical data created: 183398
Tick series "EURUSD": Requested number of days: 1, Historical data created: 148089
Subscribed to Depth of Market  AUDUSD
Subscribed to Depth of Market  EURUSD
============= Beginning of parameter list: "EURUSD" (Euro vs US Dollar) ==================
Status: Major Forex symbol
Index in Market Watch: 2
Custom symbol: No
Price type used for generating bars: Bars are built based on Bid prices
Symbol selected in Market Watch: Yes
Symbol visible in Market Watch: Yes
Number of deals in the current session: 0
Total number of Buy orders at the moment: 0
Total number of Sell orders at the moment: 0
Volume of the last deal: 0
Maximal day volume: 0
Minimal day volume: 0
Time of the last quote: 2021.01.26 22:41:04.852
Number of decimal places: 5
Digits after a decimal point in the value of the lot: 2
Spread value in points: 2
Floating spread: Yes
Maximum number of requests displayed in DOM: 10
Subscription to DOM: Yes
Contract price calculation mode: Forex mode
Order execution type: No trading limitations
Trading start date for an instrument: (No)
Trading end date for an instrument: (No)
Minimal indention from the close price to place Stop orders: 0
Freeze distance for trading operations: 0
Deal execution mode: Instant execution
Swap calculation model: Swaps charged in points
Triple-day swap: Wednesday
Calculating hedging margin using the larger leg: No
Flags of allowed order expiration modes: 
 - Unlimited (Yes)
 - Valid till the end of the day (Yes)
 - Time is specified in the order (Yes)
 - Date specified in order (Yes)
Flags of allowed order filling modes: 
 - Return (Yes)
 - Fill or Kill (Yes)
 - Immediate or Cancel order (No)
Flags of allowed order types: 
 - Market order (Yes)
 - Limit order (Yes)
 - Stop order (Yes)
 - Stop limit order (Yes)
 - StopLoss (Yes)
 - TakeProfit (Yes)
 - Close by (Yes)
StopLoss and TakeProfit order validity periods: Pending orders and Stop Loss/Take Profit levels valid for unlimited period until their explicit cancellation
Option type: European option may only be exercised on a specified date
Option right: Call option gives you right to buy asset at specified price
Background color of the symbol in Market Watch: (No)
------
Bid price: 1.21665
Highest Bid price of the day: 1.21760
Lowest Bid price of the day: 1.21078
Ask price: 1.21667
Highest Ask price of the day: 1.21760
Lowest Ask price of the day: 1.21081
Real volume of the day: 0.00
Maximum real volume of the day: 0.00
Minimum real volume of the day: 0.00
Option execution price: 0.00000
Point value: 0.00001
Calculated tick value for a position: 1.00
Calculated tick value for a winning position: 1.00
Calculated tick value for a losing position: 1.00
Minimum price change: 0.00001
Trade contract size: 100000.00
Accrued interest: 0.00
Initial bond value set by the issuer: 0.00
Liquidity rate: 0.00
Minimum volume for deal execution: 0.01
Maximum volume for deal execution: 500.00
Minimal volume change step for deal execution: 0.01
Maximum allowed aggregate volume of an open position and pending orders in one direction: 0.00
Long swap value: -0.70
Short swap value: -1.00
Initial margin: 0.00000000
Maintenance margin for an instrument: 0.00000000
Initial margin requirement applicable to long positions: 1.00000000
Initial margin requirement applicable to BuyStop orders: (Value not set)
Initial margin requirement applicable to BuyLimit orders: (Value not set)
Initial margin requirement applicable to BuyStopLimit orders: (Value not set)
Maintenance margin requirement applicable to long positions: (Value not set)
Maintenance margin requirement applicable to BuyStop orders: (Value not set)
Maintenance margin requirement applicable to BuyLimit orders: (Value not set)
Maintenance margin requirement applicable to BuyStopLimit orders: (Value not set)
Initial margin requirement applicable to short positions: 1.00000000
Initial margin requirement applicable to SellStop orders: (Value not set)
Initial margin requirement applicable to SellLimit orders: (Value not set)
Initial margin requirement applicable to SellStopLimit orders: (Value not set)
Maintenance margin requirement applicable to short positions: (Value not set)
Maintenance margin requirement applicable to SellStop orders: (Value not set)
Maintenance margin requirement applicable to SellLimit orders: (Value not set)
Maintenance margin requirement applicable to SellStopLimit orders: (Value not set)
Total volume of deals in the current session: 0.00
Total turnover in the current session: 0.00
Total volume of open positions: 0.00
Total volume of Buy orders at the moment: 0.00
Total volume of Sell orders at the moment: 0.00
Open price of the session: 1.21371
Close price of the session: 1.21413
Average weighted price of the session: 0.00000
Settlement price of the current session: 0.00000
Minimum allowable price value for the session: 0.00000
Maximum allowable price value for the session: 0.00000
Size of a contract or margin for one lot of hedged positions: 100000.00
------
Symbol name: EURUSD
Name of the underlaying asset for a derivative symbol: (No)
Instrument base currency: "EUR"
Profit currency: "USD"
Margin funds currency: "EUR"
Source of the current quote: (No)
Symbol description: "Euro vs US Dollar"
Symbol name in ISIN system: (No)
Address of the web page containing symbol information: "http://www.google.com/finance?q=EURUSD"
Location in the symbol tree: "Forex\EURUSD"
Name of the category or sector the symbol belongs to: (No)
Name of the exchange in which the security is traded: (No)
================== End of parameter list: "EURUSD" (Euro vs US Dollar) ==================
 
Library initialization time: 00:00:09.953

Uma linha do método Refresh() da classe da série de ticks para o símbolo AUDUSD será exibida num comentário no gráfico - o número de ticks copiados recentemente, hora passada, hora atual e o número total de objetos de dados de ticks presentes na lista de séries de ticks:



O que vem agora?

No próximo artigo, começaremos a criar a funcionalidade de biblioteca que permite trabalhar com o livro de ofertas dos símbolos.

Todos os arquivos da versão atual da biblioteca e o arquivo do EA de teste para MQL5 estão anexados abaixo. Você pode baixá-los e testar tudo sozinho.
Se você tiver perguntas, comentários e sugestões, poderá expressá-los nos comentários do artigo.

Complementos

*Artigos desta série:

Trabalhando com séries temporais na biblioteca DoEasy (Parte 35): objeto "Barra" e lista-série temporal do símbolo
Trabalhando com séries temporais na biblioteca DoEasy (Parte 36): objeto das séries temporais de todos os períodos usados do símbolo
Trabalhando com séries temporais na biblioteca DoEasy (Parte 37): coleção de séries temporais - banco de dados de séries temporais para símbolos e períodos
Trabalhando com séries temporais na biblioteca DoEasy (Parte 38): coleção de séries temporais - atualização em tempo real e acesso aos dados do programa
Trabalhando com séries temporais na biblioteca DoEasy (Parte 39): indicadores com base na biblioteca - preparação de dados e eventos das séries temporais
Trabalhando com séries temporais na biblioteca DoEasy (Parte 40): indicadores com base na biblioteca - atualização de dados em tempo real
Trabalhando com séries temporais na biblioteca DoEasy (Parte 41): exemplo de indicador multissímbolo multiperíodo
Trabalhando com séries temporais na biblioteca DoEasy (Parte 42): classe de um objeto de buffer abstrato de indicador
Trabalhando com séries temporais na biblioteca DoEasy (Parte 43): classes de objetos de buffers de indicador
Trabalhando com séries temporais na biblioteca DoEasy (Parte 44): classe-coleção de objetos de buffers de indicador
Trabalhando com séries temporais na biblioteca DoEasy (Parte 45): buffers de indicador multiperíodo
Trabalhando com séries temporais na biblioteca DoEasy (Parte 46): buffers de indicador multiperíodos multissímbolos
Trabalhando com séries temporais na biblioteca DoEasy (Parte 47): indicadores padrão multiperíodos multissímbolos
Trabalhando com séries temporais na biblioteca DoEasy (Parte 48): indicadores multissímbolos multiperíodos num buffer de uma subjanela
Trabalhando com séries temporais na biblioteca DoEasy (Parte 49): indicadores padrão multiperíodos multissímbolos multibuffer
Trabalhando com séries temporais na biblioteca DoEasy (Parte 50): indicadores padrão multiperíodos multissímbolos com deslocamento
Trabalhando com séries temporais na biblioteca DoEasy (Parte 51): indicadores padrão multiperíodos multissímbolos compostos
Trabalhando com séries temporais na biblioteca DoEasy (Parte 52): natureza multiplataforma de indicadores padrão multiperíodos multissímbolos de buffer único
Trabalhando com séries temporais na biblioteca DoEasy (Parte 53): classe do indicador base abstrato
Trabalhando com séries temporais na biblioteca DoEasy (Parte 54): classes herdeiras do indicador base abstrato
Trabalhando com séries temporais na biblioteca DoEasy (Parte 55): classe-coleção de indicadores
Trabalhando com séries temporais na biblioteca DoEasy (Parte 56): objeto de indicador personalizado, obtenção de dados a partir de objetos-indicadores numa coleção
Trabalhando com séries temporais na biblioteca DoEasy (Parte 57): objeto de dados do buffer do indicador
Trabalhando com séries temporais na biblioteca DoEasy (Parte 58): séries temporais de dados de buffers de indicadores
Trabalhando com preços na biblioteca DoEasy (Parte 59): objeto para armazenar dados de um tick
Trabalhando com preços na biblioteca DoEasy (Parte 60): lista-série de dados de tick do símbolo
Trabalhando com preços na biblioteca DoEasy (Parte 61): coleção de séries de ticks para símbolos


Traduzido do russo pela MetaQuotes Ltd.
Artigo original: https://www.mql5.com/ru/articles/8988

Arquivos anexados |
MQL5.zip (3881.55 KB)
Aplicação prática de redes neurais no trading (Parte 2). Visão computacional Aplicação prática de redes neurais no trading (Parte 2). Visão computacional
O uso da visão computacional permite treinar redes neurais, usando uma representação visual do gráfico de preços e indicadores. Este método nos permite operar mais livremente com todo o conjunto de indicadores técnicos, uma vez que não requer feed digital para a rede neural.
Força bruta para encontrar padrões (Parte III): novos horizontes Força bruta para encontrar padrões (Parte III): novos horizontes
Este artigo dá continuidade ao tópico sobre força bruta, trazendo novos recursos de análise de mercado para o algoritmo do meu programa e acelerando, assim, a velocidade da análise e a qualidade dos resultados finais, o que fornece a visão da mais alta qualidade de padrões globais dentro da estrutura desta abordagem.
Trabalhando preços na biblioteca DoEasy (Parte 63): livro de ofertas, classe de ordem abstrata do livro de ofertas Trabalhando preços na biblioteca DoEasy (Parte 63): livro de ofertas, classe de ordem abstrata do livro de ofertas
Neste artigo, começaremos a desenvolver funcionalidades para trabalhar com o livro de ofertas. Criaremos uma classe de objeto para uma ordem abstrata do livro de ofertas e dos seus herdeiros.
Redes neurais de maneira fácil (Parte 10): Atenção Multi-Cabeça Redes neurais de maneira fácil (Parte 10): Atenção Multi-Cabeça
Nós já consideramos anteriormente o mecanismo de self-attention (autoatenção) em redes neurais. Na prática, as arquiteturas de rede neural modernas usam várias threads de self-attention paralelas para encontrar várias dependências entre os elementos de uma sequência. Vamos considerar a implementação de tal abordagem e avaliar seu impacto no desempenho geral da rede.