Analysis of MVC architecture in PHP framework (with examples)

The content of this article is about the analysis of the MVC architecture in the PHP framework (with examples). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Before talking about the MVC architecture, let’s talk about the PHP framework first. Many, many people who have learned the PHP language are faced with various PHP frameworks. What about TP, Yii, CI, and the very popular laravel, etc.

Most of them will say that they are based on the MVC architecture, and then you have to try to understand the logic of MVC, and try to use this logic to build a website, and then they will say that MVC is really delicious~

Interview

In many PHP interviews, questions about MVC may be asked, such as what does MVC mean and how to understand this architecture. However, many people understand that model is a model, which corresponds to the table structure in the database; view corresponds to the page and is used for display; controller is mainly used to write various logics and associate data with page display.

The above answer is basically no problem, but is the structure of a website really that simple? Obviously not

Design

Before talking, let us first understand one of the design patterns: the mediator pattern. A vivid understanding is: the adapter between the Hong Kong Bank plug and the National Bank plug.

In the MVC architecture, the controller is this adapter. It is only responsible for transferring the data in the model to the view. For visitors, they cannot see the real data saved in the model. From another perspective, this intermediary model can facilitate friendly communication between two layers of data.

Climbing the Pit

Is this model really that good? As the business logic becomes more and more complex, you will find that there are more and more codes in the controller, and you will not even want to adjust and optimize the redundant code.

But from a macro perspective, the website just has more requests, more forms, more pages, and nothing else. Why is this?

That’s right, it’s because there are many things like this or that, causing each method in the controller to be very long, so the solution that can be thought of is to split it.

If you have used the Yii framework, then you will know that the easiest way is to add a request form layer. The code is as follows:

class AuthController {
    public function login() {
        $FLogin = new loginForm();
        $FLogin->save();
    }
}

// 一般在独立的文件夹中
class loginForm {
    public function __construct() {
        $post = $_POST;
    }
    
    public function save() {
    }
}

The above is to solve the problem of the form form in the controller. This problem Basically it can alleviate many coding problems.

divergence

From the perspective of solving the form layer, there are actually many similar problems that can be solved. We know that there is a framework called vue.js on the front end, which mentions a concept called the MVVM model.

In fact, when displaying complex pages, the backend can also use this thing to output data when outputting data to the outside world. As for how to build such a model, it depends on the business logic.

Here is a simple example of the user center, because often more than just data from one table is needed here:

class AuthController {
    public function userCenterAction() {
        return new userVM();
    }
}

class userVM {
    public $user;
    public $orders;
    public $other;

    public function __construct() {
        $this->user = $this->getUser();
        $this->orders = $this->getOrders();

        $this->handle();
    }

    private function getUser() {
        return NULL;
    }

    private function getOrders() {
        return NULL;
    }

    private function handle() {
    }
}

In the above code, there is a VM layer, where the code for obtaining data can be placed. In their respective methods, and then freely combined in the handle method. This way the code in the controller is also very easy to manage.

Think about it again, are there other layers that can be encapsulated? In fact, there are some, such as the request layer, the validate layer that is often encapsulated by the framework, and the popular Middleware layer in laravel, etc. It can only be said that the more complex the system, the more layers it has.

Behind every complex system lies the design ideas of senior development engineers and architects. Having said so much above, I don’t know if readers can understand these things. Take the above code as an example, it contains another design pattern: the builder pattern.

Summary

If you write a lot of code, you will know the truth behind it. When a new framework is born, the focus gradually changes from learning the framework to how the framework is designed and what kind of problems it solves. Where better technologies and methods are used, and what can be gained from them. What are the design ideas in some places? Are there any better designs? Why can I think of it but the other party can't? Is there something I've missed?

In the past few years, I have used various PHP frameworks, ranging from CI to Symfony. Without using so many frameworks, you won’t be able to experience these things. Learning programming is actually the same as English, there is no shortcut.

Write more, think more, practice more...

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