Hooks

Hooks in CodeIgniter allow you to modify the behavior of the framework without modifying core files. This is accomplished by calling a set of user-defined functions at certain points in the execution of the framework. Hooks can be used for various purposes such as modifying inputs, output, and final rendered output.

Syntax

The syntax for Hook in CodeIgniter is as follows:

$hook['pre_controller'] = array(
    'class'    => 'MyClass',
    'function' => 'Myfunction',
    'filename' => 'Myclass.php',
    'filepath' => 'hooks'
);

Example

To create a hook after loading a library, create a PHP file in the application/hooks directory with the following code:

class MyHook
{
    public function do_something()
    {
        // Some code here
    }
}

Then, in the application/config/config.php file, add the following code under the "Hooks" section:

$config['enable_hooks'] = TRUE;

$hook['post_controller_constructor'][] = array(
    'class' => 'MyHook',
    'function' => 'do_something',
    'filename' => 'MyHook.php',
    'filepath' => 'hooks'
);

Explanation

In the above example, the MyHook class has a method named do_something which will be called when the hook is triggered. The hook is defined under the "Hooks" section in the config.php file and specifies the class name, method name, filename, and filepath of the hook.

In this example, the hook is defined to run after the controller constructor has been called. This hook will call the do_something method in the MyHook class.

Use

Hooks in CodeIgniter can be used for various purposes such as modifying inputs, output, and final rendered output. Hooks can be used to perform pre and post actions associated with framework execution. Common use cases include logging, modifying data, and implementing security checks.

Important Points

• Hooks are executed in the order they are defined in the config.php file.
• Multiple hooks can be defined for the same hook point.
• Hooks can be enabled or disabled globally using the enable_hooks configuration parameter.

Summary

Hooks in CodeIgniter allow you to modify the behavior of the framework without modifying core files. Hooks can be used for various purposes such as modifying inputs, output, and final rendered output. Hooks can be enabled or disabled globally, and are executed in the order they are defined in the config.php file.