How to Code & Compile MQL5 in Visual Studio - A Complete Guide

Well, we are talking here about the Open Source project from Microsoft called Visual Studio Code. It is completely FREE for personal and commercial use. Download it from here: code.visualstudio.com. Install it - the process is plain simple and common. Then, launch it. VSC will automatically launch a web page with initial tutorials, it is a good idea to have a peek at all those features since VSC is a very powerful tool and totally hackable to your needs. And that's tha magic behind it.

If you ever used editors like Sublime Text or Atom, you will find yourself at home with the Command Palette (CTRTL-SHIFT-P). This is were all the magic happens. Just type what you want, and voilà! If you never used editors such those, it will be a little strange since all settings are done through the use of JSON files, even the Main Preferences of VSC is a JSON file, but it is all very well docummented and easy to understand. So if this is your case, I recommend you to watch a couple of videos to get comfortable with your new home for coding. This is my current Code screen after applying all my desired configurations:

SETTING YOUR WORKSPACE

After launching VSC you will be presented with someting like this (after closing the Welcome Screen). Just click on Open Folder to prepare your environment for MQL5 coding:

The folder to be referenced is the base MQL5 tree of your Metatrader data (where all indicators, experts and code reside). If you don't know where is it, just go to your Metaeditor, right-click on the MQL5 top node and choose "Open Folder":

To get the complete path, just click on the path address and Windows will give you the full stuff. Copy this address to the Clipboard.

And that's it! You will have something like the screen below:

You can start browsing and opening all your files! But of course you need to start to set up your environment to your taste. By now, you will have all your world in plain Black&White. Why? by default VSC installation do not recognize MQL as a known language in order to activate the proper Syntax Highlighting.

SETTING SYNTAX HIGHLIGHTING

One of the marvelous things about VSC is its Marketplace of Extensions, that can be plugged in at your command. Fast and Easy! You can visit the VSC Marketplace here. There are a couple of packages that could enable the recognition of the MQL5. You can install them directly from VSC or from the Marketplace (the extensions URLs will be activated within VSC). It is your choice. Let's use the Marketplace, searching for the keyword "MQL":

To know better each of the found items, just click on each one to see the description and usage. Start by installing the "MQL4 Syntax Highlighting" extension. Just click on the big green "Install" button on the web page. The extension installation will be redirected to your VSC window. In VSC, click on the install button again. After installing you very first extension, instead of a green "install" button you will see now 2 Blue buttons: Reload and Uninstall. This is the common behavior of VSC for almost every extension you install. Because VSC just received a new extension in its environment you must reload the whole editor, just click "Reload" and that's it, you are done!

* Special thanks to Emmanuel Roche (NervTech) and @Nicholishen for those great extensions! *

If you go and open any .mq5 file again you will see your code in total color!

Then, install the "MQL Extension Pack" which will install the other 2 extensions (Snippets and Syntax Over CPP) and other 2 more extensions needed for the whole thing work (Code Intellisense). After all the installations, click on the Extensions Manager icon in your VSC envirnonment and click on the "mql-syntax-over-cpp" extension. You need to map the MQL file extensions in order for all to work. Read the "requirements" sections of this extension and copy the code stated there to your clipboard:

Then, go to the menu FILE > PREFERENCES > SETTINGS. A 2-panel window will open. The left side is read-only and it is intended for you to read what is set in the environment and what could be changed (written/copied) to the right side of the window = Your User Settings. All User Settings are unique, so my settings are different from yours, but the current addition should be like this (don't forget the proper formatting of JSON files, do not forget to add commas when you add content to an existing file):

Also, if you want to disable those red squiggles that would appear in some places on your code, just add to your User Settings the line below, as shown in the previous picture. Don't forget the commas!

"C_Cpp.errorSquiggles": "Disabled"

And that's it regarding Syntax Highlighting.

SETTING YOUR THEME

If the way of the colors presented in your code are not of your taste, you can change them - Another cool thing of VSC. There are tons of Themes in the Marketplace you can try. Some extensions could come with a multiple range of themes within a single Extension, others just have 1 theme per Extension. One I recommend is the "Rainglow" which comes with several cool color palettes. Feel free to try several of them until you choose the perfect one for you, just remember to uninstall all the unused ones to avoid bloating your VSC installation.

After installing a theme (do not forget to "Reload" your system), you can change the theme of your VSC using the keys CTRL-K-T (K and T pressed in sequence, while holding the CTRL) and a list of all the installed themes will appear. And, another violà!

TIP: Instead of choosing your Theme with the mouse, use the Up and Down arrows to cycle the theme list, so the Theme will be applied to your interface in realtime!

PREPARING INTELLISENSE

#include References

Metatrader itself knows exactly where all its native #includes are (i.e. Trade class, Symbol Class, etc, etc...) but VSC don't. When you open a .mq5 file that has an #include of this type, a visual warning will appear on the code:

To fix this, open the Command Palette (CTRL-SHIFT-P) and type "Config". Choose "C/Cpp: Edit Configurations...".

VSC will open the file c_cpp_properties.json. Just add one more line into the "includePath" section, referencing the full path to YOUR Metatrader 5 installation, adding at the end of the path the "\\Include" folder (you can find the exact location of your installation by right-clicking on the "MQL5" item in the Metaeditor Navigator, and then choose "Open Folder"). When inserting the new line into the JSON file, do not forget to add a comma at the previous line:

VERSION CONTROL OF YOUR CODE

[
    { "key": "f5", "command": "workbench.action.reloadWindow" },
    { "key": "ctrl+shift+c", "command": "workbench.action.tasks.build" },
    { "key": "ctrl+shift+x", "command": "workbench.action.tasks.runTask", "args": "Compile-Project-X" },
    { "key": "f1", "command": "workbench.action.tasks.runTask", "args": "launch_offline_help" }
]

Tasks can be run manually via Command Pallete (just type "task", and choose "Run Task") or via key binding. Tasks are saved in a JSON file called "tasks.json". If it is your first time creating a task for your VSC installation, bring up the Command Palette and type "Tasks" and choose the option "Configure Task". Then, choose the option of "Create tasks.json file from template". And then, Choose "Others".

Now you will have an empty template for your tasks. Just save it. This file, as with others you create, they will be bound and saved under the Root folder you chose for your project, that in our case is our base MQL5 data folder where we save all our work:

So, let's configure our first task, the launch of the Context-Sensitive MQL5 help...

TASK TO LAUNCH CONTEXT SENSITIVE HELP  (F1)

Do you remember that we made a mapping to the key F1 to call the the label "launch_offline_help"? Well, let's create a task for it. Open your tasks.json from the navigator tree, or use the Command Palette (then type "task" and choose "Configure Task"). Since you have no useful code in the file (because it is new), you can just copy and paste the whole code below over the one you have in your screen:

(don't forget to update the path on the code to YOUR Metatrader instalation!)

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {   //set the label ID for the MQL5 Reference context-sensitive help to be launched
            "label": "launch_offline_help",
            "type": "shell",
            "presentation": {
                "echo": false,
                "reveal": "silent",
                "focus": false,
                "panel": "shared",
                "showReuseMessage": false
            },
            "command": "hh.exe",
            "args": [
                "mk:@MSITStore:C:\\Users\\Acme\\AppData\\Roaming\\MetaQuotes\\Terminal\\Help\\mql5.chm::/${selectedText}.htm"
            ]
        }
    ]
}

I will not explain all the code here, please use the Tasks documentation to learn all the meaning of all the standard Tasks instructions present in the JSON, the important line is the process of invoking the Windows Help (the hh.exe file in the command statement) and passing to it as an argument the code to activate directly the specific Help Topic that is currently and supposedly selected by you in you MQL code file. "${selectedText}" is a global VSC variable that holds the current cursor selection of a piece of data. Nothing is perfect, so if in the case of nothing is currently selected on the code, if you press F1 it will produce an error message. But, I can live with that.

TASK TO LAUNCH THE COMPILE OF MQL CODE  (CTRL-SHIFT-C / CTRL-SHIFT-X)

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "Compile-Project-X",
            "type": "shell",
            "command": "C:\\Users\\Acme\\AppData\\Roaming\\MetaQuotes\\Terminal\\83D4764E0403A8685E84D6FCAB361879\\MQL5\\Compile-MQL.ps1  C:\\Users\\Acme\\AppData\\Roaming\\MetaQuotes\\Terminal\\83D4764E0403A8685E84D6FCAB361879\\MQL5\\Experts\\ProjectX\\ProjectX.mq5",
            "presentation": {
                "echo": true,
                "reveal": "always",
                "focus": false,
                "panel": "shared",
                "showReuseMessage": false
            }
        },
        {
            "label": "Compile-MQL",
            "type": "shell",
            "command": "C:\\Users\\Acme\\AppData\\Roaming\\MetaQuotes\\Terminal\\83D4764E0403A8685E84D6FCAB361879\\MQL5\\Compile-MQL.ps1 ${file}",
            "presentation": {
                "echo": true,
                "reveal": "always",
                "focus": false,
                "panel": "shared",
                "showReuseMessage": false
            },
            "group": {
                "kind": "build",
                "isDefault": true
            }
        },
        {
            "label": "launch_offline_help",
            "type": "shell",
            "presentation": {
                "echo": false,
                "reveal": "silent",
                "focus": false,
                "panel": "shared",
                "showReuseMessage": false
            },
            "command": "hh.exe",
            "args": [
                "mk:@MSITStore:C:\\Users\\Acme\\AppData\\Roaming\\MetaQuotes\\Terminal\\Help\\mql5.chm::/${selectedText}.htm"
            ]
        }
    ]
}

#gets the File To Compile as an external parameter... Defaults to a Test file...
Param( $FileToCompile = "C:\Users\Acme\AppData\Roaming\MetaQuotes\Terminal\83D4764E0403A8685E84D6FCAB361879\MQL5\Experts\Test.mq5")

#cleans the terminal screen and sets the log file name...
Clear-Host
$LogFile = $FileToCompile + ".log"

#before continue check if the Compile File has any spaces in it...
if ($FileToCompile.Contains(" ")) {
    "";"";
    Write-Host "ERROR!  Impossible to Compile! Your Filename or Path contains SPACES!" -ForegroundColor Red;
    "";
    Write-Host $FileToCompile -ForegroundColor Red;
    "";"";
    return;
}

#first of all, kill MT Terminal (if running)... otherwise it will not see the new compiled version of the code...
Get-Process -Name terminal64 -ErrorAction SilentlyContinue | Where-Object {$_.Id -gt 0} | Stop-Process

#fires up the Metaeditor compiler...
& "C:\Program Files\MetaTrader 5\metaeditor64.exe" /compile:"$FileToCompile" /log:"$LogFile" /inc:"C:\Users\Flavio\AppData\Roaming\MetaQuotes\Terminal\83D4764E0403A8685E84D6FCAB361879\MQL5" | Out-Null

#get some clean real state and tells the user what is being compiled (just the file name, no path)...
"";"";"";"";""
$JustTheFileName = Split-Path $FileToCompile -Leaf
Write-Host "Compiling........: $JustTheFileName"
""

#reads the log file. Eliminates the blank lines. Skip the first line because it is useless.
$Log = Get-Content -Path $LogFile | Where-Object {$_ -ne ""} | Select-Object -Skip 1

#Green color for successful Compilation. Otherwise (error/warning), Red!
$WhichColor = "Red"
$Log | ForEach-Object { if ($_.Contains("0 error(s), 0 warning(s)")) { $WhichColor="Green" } }

#runs through all the log lines...
$Log | ForEach-Object {
     #ignores the ": information: error generating code" line when ME was successful
     if (-Not $_.Contains("information:")) {
           #common log line... just print it...
           Write-Host $_ -ForegroundColor $WhichColor
     }
}

#get the MT Terminal back if all went well...
if ( $WhichColor -eq "Green") { & "C:\Program Files\MetaTrader 5\terminal64.exe" }

And that's it! Your are ready to Roll!

EXAMPLES OF COMPILATION FEEDBACK

Succesfull compilation:

Compilation with error. The cool thing is that if you CTRL-Click with your mouse on each error you will be directed exactly to the offending line on your code!

SAVING YOUR WORKSPACE

Well, the last thing you should do now is saving (backing up) your Workspace. There is a whole page explaining what is the difference between User Settings and Workspace Settings that is worth looking. I recommend you to save it in the cloud (Dropbox, GDrive, etc). Just go to the menu FILE > SAVE WORKSPACE AS, and you are done!

I hope this tutorial be helpful for those who always wanted a better IDE to build solutions in MQL5. I apologize for any inaccuracy on the text above, just ping me and I will correct/add/remove the glitches.

FINAL WORDS

All those steps presented in this article were done in a Windows 10 64-bits installation. I don't know if it works in Win7 or Win8. If anything breaks or didn't go well as shown on the steps above, it is YOUR homework to solve the problems. I'm assuming that you are a Power User like me trying to get the most out of a development process and hack your way in. There is plenty of information on the web about Windows, Visual Studio Code, Powershell and JSON. So, before you ping me try to Google the stuff you need. And the last thing, do not even ask me things like "How do I enable my Multi-Cursors?"...

Live Long and Prosper.