Yii Framework Guide in PHP

PHP language is a widely used open source scripting language. It has become one of the main tools for website development due to its flexibility, efficiency, security and ease of use.

As WEB applications become more and more complex, developers are constantly looking for new ideas and frameworks to simplify and optimize the development process. The Yii framework is widely used in the field of PHP development. It not only provides efficient tools and interfaces, but also greatly improves development efficiency.

This article will introduce the characteristics, installation, configuration and common application methods of Yii framework to help readers better master the use of Yii framework.

1. Overview of Yii Framework

Yii framework is an open source, efficient and excellent PHP development framework. It has powerful MVC design pattern support and can easily integrate existing code and external libraries. As well as being easy to expand, the Yii framework has received widespread attention from developers.

1.1 Yii framework features

• Efficiency: With its high-speed performance and powerful cache support, the Yii framework can quickly generate websites in a very short time.
• Security: The Yii framework adopts a reliable authorization and verification mechanism to ensure the security of the application.
• Flexibility: The MVC structure and toolset of the Yii framework support interactive web applications at different levels. Developers can do easy modular development in this framework.
• Ease of use: The Yii framework has many powerful functions and features built in, and also provides an easy-to-use command line interface, quick installation and simple configuration.

1.2 Advantages of the Yii framework

The Yii framework simplifies PHP development by providing a quick code generator, command line tools, featured components, and customizable template engines. process, improving developer productivity and efficiency. At the same time, the Yii framework also improves the reliability, practicality and performance of applications, and optimizes program running speed.

2. Installation and configuration of Yii framework

The installation of Yii framework is very simple. It can be installed by following the steps below.

2.1 Environment detection

Yii framework needs to access MySQL, PHP extension, PDO extension and Intl extension. Therefore, before installing Yii framework, we need to check the environment through the following command:

php -r "echo PHP_VERSION;"
php -m

At the same time, you also need to check whether the following PHP extensions are installed and enabled:

• pdo_mysql
• intl

2.2 Yii framework installation

Yii2 applications can be installed through Composer. The specific steps are as follows:

(1) Install Composer

First, you need to download and install Composer: https://getcomposer.org/

(2) Create a Yii framework project And install the Yii framework

composer create-project --prefer-dist yiisoft/yii2-app-basic my_project

This command will create a new Yii application in the my_project/ directory. First cd to the my_project directory and enter the following command to install yii:

php composer.phar install

2.3 Yii framework Configuration

After completing the installation, we need to open the configuration file and configure the application's database, cache and other settings. The framework provides a convenient way to quickly launch and configure applications.

Open the my_project/config/db.php file, configure the application database:

return [
    'class' => 'yiidbConnection',
    'dsn' => 'mysql:host=localhost;dbname=databasename',
    'username' => 'username',
    'password' => 'password',
    'charset' => 'utf8',
];

Open the my_project/config/web.php file, configure the application URL and enable caching:

return [
    'id' => 'basic',
    'basePath' => dirname(__DIR__),
    'components' => [
        'cache' => [
            'class' => 'yiicachingFileCache',
        ],
        'urlManager' => [
            'enablePrettyUrl' => true,
            'showScriptName' => false,
        ],
    ],
];

3. Common application methods of Yii framework

In Yii framework, there are many common application methods, such as:

3.1 Model view controller architecture

Yii framework MVC architecture simplifies the application development and maintenance process. Under this architecture, the application is divided into three components: model, view and controller.

In the Yii framework, the model is responsible for data processing, the view is responsible for data presentation, and the controller is responsible for the coordination between the model and the view.

3.2 Database Operation

The Yii framework provides a very convenient database operation method and supports multiple types of databases, providing efficient performance when operating different databases. For example:

use yiidbQuery;

// SELECT * FROM `user`
$users = (new Query())->from('user')->all();

$lastName = 'Smith';

// SELECT * FROM `user` WHERE `last_name` = :lastName
$user = (new Query())
    ->from('user')
    ->where(['last_name' => $lastName])
    ->one();

3.3 Forms and Validation

Yii framework simplifies the form processing and validation process. Data can be verified through built-in form validation rules, and powerful client-side validation support is provided. For example:

public function rules()
{
    return [
        // username and password are both required
        [['username', 'password'], 'required'],

        // password is validated by validatePassword()
        ['password', 'validatePassword'],
    ];
}

public function validatePassword($attribute, $params)
{
    if (!$this->hasErrors()) {
        $user = $this->getUser();

        if (!$user || !$user->validatePassword($this->password)) {
            $this->addError($attribute, 'Incorrect username or password.');
        }
    }
}

3.4 Template engine

The Yii framework has a built-in fast template engine to generate pages. This template engine mainly consists of two parts: layout and fragments. The final output of the fragment is placed inside the layout. For example:

// views/site/index.php
<?php $this->beginContent('@app/views/layouts/main.php'); ?>
    <div class="row">
        <div class="col-lg-12">
            <?= $content ?>
        </div>
    </div>
<?php $this->endContent(); ?>

3.5 Backend management system

Yii framework supports the rapid development of backend management systems, and provides a wealth of templates and components to allow you to quickly create a complete backend management system.

Conclusion

Yii framework is a very powerful PHP framework. It has attracted the attention of more and more Web developers due to its efficiency, flexibility and ease of use. . This article introduces the characteristics and advantages of the Yii framework, the installation and configuration process, and its common applications. I hope it will be helpful to readers who are new to Yii framework.

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