Analysis of the architecture of applications in the Laravel framework

A typical programmer interacts with Laravel through command line tools to generate and manage Laravel project environments. Laravel comes with an excellent command line tool called Artisan that you can use to generate framework code and database schema. Artisan can handle everything from database schema migration to resource and configuration management.

Convention over configuration

One of the interesting features of Laravel is that it imposes some pretty serious rules on how to build web applications. limit. Surprisingly, these restrictions make creating applications much easier—a lot easier. Let's take a look at why.

Laravel differs from other vertically integrated development environments in its strong preference for convention over configuration. While some Java, Python or PHP frameworks often require a lot of XML configuration, Laravel requires almost no configuration to start with (maybe just a few lines in PHP). This avoidance of configuration files makes it very unique, and the recognizable code structure is the same in all Laravel applications.

One project structure to rule them all!

It's no surprise that all Laravel projects basically have the same directory structure - every file in it has its designated place. Through this agreed directory result, developers can be ensured to work according to the "Laravel way".

Figure 1.1 shows what the Laravel project directory structure looks like:

Figure 1.1 Laravel project directory structure

As you can see In this way, Laravel only contains 4 folders, and there are some subfolders under these 4 folders. Is it stressful to see such rich subfolders for the first time? I will introduce them one by one. Most of our development work will be carried out under the app/ folder.

The following is a basic introduction to each folder and file:

As mentioned above, /app is where all the fun happens, let’s take a deeper look at the structure of this directory.

Figure 1.2 Displays the detailed information of the /app folder:

Figure 1.2 The detailed information of the app folder

The following is a detailed introduction:

Put a lot of thought into creating and naming folders, and the result is an application with a good file system.

What you get here: MVC

Model-View-Controller (MVC)

Let’s get into the high-level aspects of working with a Laravel application Overview. You may have noticed that the standard Laravel application structure consists of an application directory app/, which contains three subdirectories: models/, views/, and controllers/. This reveals that Laravel follows the model-view-controller (MVC) architectural pattern, which forces the separation of "business logic" input to display logical relationships from the graphical user interface (GUI). In the case of Laravel web applications, business logic usually consists of data models like users, blog posts, etc. The GUI is just a web page in the browser. The MVC design pattern is very popular in the field of web development.

Three components of the MVC pattern:

• Model

• View

• Controller

[Note] The original author introduced the three components of MVC in detail here, but I will not introduce them here due to space.

Laravel Components

A typical Laravel application contains the MVC components mentioned above, as shown below:

When interacting with Laravel, the browser sends a request, the web server receives the request and passes it to the Laravel routing engine. Laravel routing receives the request and then redirects to the appropriate controller class method based on the route's URL pattern.

Then the controller class takes over. In some cases, the controller will immediately render a view, which is a template that is converted into HTML and sent back to the browser. More commonly with dynamic websites, the controller interacts with the model, which is a PHP object that represents an element in the application (such as a user, a blog post) and is responsible for communicating with the database. After calling the model, the controller renders the final view (HTML, CSS, and images) and returns the complete web page to the user's browser.

Laravel promotes the concept that models, views, and controllers should be kept fairly independent by storing these elements in separate code files in different directories. This is where the Laravel directory structure comes into play.

Design patterns like MVC were created to make developers’ lives easier. This is where Laravel is better than PHP which does not use any pattern. If this discussion is abstract, now, don't worry! When you start working with Laravel, you won't even realize that you are working in a design pattern. After a while, it will become natural.

Data Model

The data model is the foundation of any application. It describes the business logic of the application. Any piece of data is represented by a database table. Laravel provides some techniques to simplify access to the database.

Laravel connects the application's data model to the database table by converting table rows in the database into PHP objects that can be easily manipulated. It also enables you to enforce business rules, describe relationships between different data models in your application, etc. For example, a person's family relationship can be described using Laravel Eloquent OR/M as follows:

class Person extends Eloquent
{
    public function mother()
    {
        return $this->belongsTo('Mother');
    }

    public function father()
    {
        return $this->belongsTo('Father');
    }

    public function spouse()
    {
        return $this->hasOne('Spouse');
    }

    public function sisters()
    {
        return $this->hasMany('Sister');
    }

    public function brothers()
    {
        return $this->hasMany('Brother');
    }
}

The above is the entire content of this article, more laravel content Please pay attention to the laravel framework introductory tutorial.

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