Simplified MVC Understanding the Heart of Web Applications

Flask is a minimalist framework that offers considerable flexibility in how you organize your application. However, it's worth noting that the MVC (Model-View-Controller) pattern aligns quite well with Flask's capabilities, particularly in the contemporary understanding of MVC within web application development.

MVC stands for Model-View-Controller and is a software architectural pattern we'll explore within the context of web development. Its core concept involves the separation of an application's logic and interface, which facilitates organized programming and enables multiple developers to collaborate on a project simultaneously. Understanding MVC is valuable not just in the realm of Python Flask development but also across various frameworks and programming languages. Some frameworks may adopt certain aspects of MVC while still remaining connected to the overall MVC concept.

Tasked with acquiring and processing data, essentially serving as the application's core processing unit. It interfaces with a database of some sort and exchanges information with the controller. The controller has the capability to request data from the model.

This handles the application's user interface, which is what the user observes during their interaction with the application. Typically, it comprises HTML/CSS components along with dynamic content sourced from the controller. The controller is responsible for communication with both the view and the model.

The controller receives user inputs from the view or URL and handles various requests (such as GET, POST, PUT, DELETE). For instance, clicking a link triggers a GET request, while submitting a form corresponds to a POST request. The controller then communicates with the model to retrieve data from the database, which it subsequently acquires and conveys to the view.

Here is a simplified depiction of the MVC architecture. The user interacts with the application's view in their web browser and can make requests, typically initiated by clicking links or providing input. These requests are processed by a router, which in turn triggers a specific controller method. If data is required, the controller communicates with the model, which interacts with the database to fetch the necessary data. Once the controller obtains the data, it proceeds to load a view and transmit the data to it. This often involves working with a template engine. Once all these steps are completed, the view is sent back to the user's browser for them to observe.

Let’s go back to the practical things for better understanding. So, in a realistic app, your method (which acts as a controller) looks like this:

An index.html template is employed here to display the page, serving as your current view.

As for the model, you have the flexibility to utilize various options, ranging from intricate object models (often implemented with ORM tools like SQLAlchemy) to the most straightforward solution that suits your requirements.

You can implement this knowledge with our Flask Intensive Course, with guarantees to complete the first web application built with MVC architecture.