How to use CodeIgniter4 framework in php?

PHP is a very popular programming language, and CodeIgniter4 is a commonly used PHP framework. When developing web applications, using frameworks is very helpful. It can speed up the development process, improve code quality, and reduce maintenance costs. This article will introduce how to use the CodeIgniter4 framework.

1. Install the CodeIgniter4 framework

The CodeIgniter4 framework can be downloaded from the official website (https://codeigniter.com/). Once the download is complete, unzip the framework files to any directory on your web server. If the Composer dependency manager is not installed on your web server, you need to run the following installation instructions in the directory where the CodeIgniter4 framework files are located:

php spark install

2. Create New Project

You can create new projects to develop using the CodeIgniter4 framework. In order to create a new project, use the following command:

php spark new project-name

3. Using Controllers

In CodeIgniter4 framework, controllers are classes used to handle user requests. You can create a controller using the following command:

php spark make:controller ControllerName

For example, the following command will create a controller named "Welcome":

php spark make:controller Welcome

After creating the controller, you need to customize it according to your needs Add method.

4. Creating Views

A view is a part of the user interface that can be accessed from your controller. Basically, a view is your HTML code and you can use PHP scripts to generate dynamic HTML content.

You can create a view using the following command:

php spark make:view ViewName

For example, the following command will create a view named "welcome_message":

php spark make:view welcome_message

Please note that the view by default Will be saved in the app/Views directory.

5. Routing

Routing is the way all user requests are handled, using the URL to determine which controller and method should be called.

You can define routing rules in the app/Config/Routes.php file. For example, the following code will handle the root URL ('/') request and call the "index" method of the "Welcome" controller:

$routes->get('/', 'Welcome::index');

6. Connect to the database

In CodeIgniter4 framework allows you to easily connect to the database. First, you need to configure the database connection in the app/Config/Database.php file. For example, the following code will use MySQL as the database driver and use the database on localhost:

$database['default'] = array(
    'DSN'      => '',
    'hostname' => 'localhost',
    'username' => 'your-username',
    'password' => 'your-password',
    'database' => 'your-database',
    'DBDriver' => 'MySQLi',
    'DBPrefix' => '',
    'pConnect' => false,
    'DBDebug'  => (ENVIRONMENT !== 'production'),
    'cacheOn'  => false,
    'cacheDir' => '',
    'charset'  => 'utf8',
    'DBCollat' => 'utf8_general_ci',
    'swapPre'  => '',
    'encrypt'  => false,
    'compress' => false,
    'strictOn' => false,
    'failover' => array(),
    'port'     => 3306,
);

After configuring the database connection, you can use the following code to create a database connection and query the data:

$db = ConfigDatabase::connect();
$query = $db->query('SELECT * FROM my_table');
$results = $query->getResult();

7. Using models

In the CodeIgniter4 framework, models are classes used to access the database. You can create a model using the following command:

php spark make:model ModelName

For example, the following command will create a model named "MyModel":

php spark make:model MyModel

After creating the model, you can add methods in it to access the database . For example:

namespace AppModels;

use CodeIgniterModel;

class MyModel extends Model
{
    protected $table = 'my_table';

    public function getRows()
    {
        return $this->findAll();
    }

    public function getRowById($id)
    {
        return $this->find($id);
    }
}

In the above code, we created a model named "MyModel" and added getRows() and getRowById() methods to get the data.

8. Summary

The CodeIgniter4 framework is a very popular PHP framework that can speed up the development process, improve code quality, and reduce maintenance costs. In this article, we discussed how to use controllers, views, routes, databases, and models. Hope this article is helpful to you.

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