Discussion of article "MVC design pattern and its possible application"

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New article MVC design pattern and its possible application has been published:

The article discusses a popular MVC pattern, as well as the possibilities, pros and cons of its usage in MQL programs. The idea is to split an existing code into three separate components: Model, View and Controller.

In this article we will consider the "classical MVC", without any complications or additional functionality. The idea is to split an existing code into three separate components: Model, View and Controller. According to the MVC pattern, these three components can be developed and maintained independently. Each component can be developed by a separate group of developers, who undertake to create new versions and to fix errors. Obviously this can make management of the overall project much easier. Furthermore, it can assist other people in understanding the code.

Let us take a look at each component.

  1. View. View is responsible for visual representation of information. In a general case it sends data to the user. There can be different methods for presenting the same data to the user. For example, data can be represented by a table, graph or chart at the same time. In other words, an MVC-based application can contain multiple views. Views receive data from the Model without knowing what is happening inside the Model.
  2. Model. The model contains data. It manages connections with data bases, sends requests and communicates with different resources. It modifies the data, verifies it, stores and deletes if necessary. The Model does not know anything about how the View works and how many Views exist, but it has the necessary interfaces through which the Views can request data. There is nothing else the Views can do, i.e. they cannot force the Model to change its state. This part is performed by the Controller. Internally, a Model can be composed of several other Models arranged in a hierarchy or working equally. The Model is not limited in this respect, except for the previously mentioned restriction — the Model keeps its internal structure in secret from the View and the Controller.
  3. Controller. The Controller implements communication between the user and the Model. The Controller does not know what the Model is doing with the data, but it can tell the Model that it is time to update the content. In general, the Controller works with the Model by its interface, without trying to understand what is happening inside it.

The relationship between the individual components of the MVC pattern can be visually represented as follows:


Author: Andrei Novichkov

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