Modules

Understanding Modules

Table of Contents

• Concepts
• The Module Class
• Examples
• Actions and Filters

Concepts - Actions and Filters

Modules are made up of methods that run at certain times during the program's execution. These "certain times" are called Hooks. There are two types of hooks: Actions and Filters.

---

Actions are defined points in the code that a module can use to hook in their method. A good example would be an Action called "sleepy_preprocess". This action runs very early in the program's lifecycle allowing you to run code before any templates have been rendered. It can be used to verify that a user has access to a page, or to start pulling content from a web service.

namespace Module\ExampleModule;

use \Sleepy\Core\Hook;
use \Sleepy\Core\Module;

class Example1 extends Module
{
    public $hooks = [
        'sleepy_preprocess' => 'start'
    ];

    public function start()
    {
        // Check if a user is logged in
    }
}

Hook::register(new Example1());

---

Filters are similar to Actions, but they are used to modify data. An example of a filter could be "render_placeholder_title". This is the Filter for the placeholder "title". In this example, we might want to add the string " | Website Name" to the end of the titles for SEO purposes.

namespace Module\ExampleModule;                     # It's good practice to namespace your module

use \Sleepy\Core\Hook;                              # We need both of these classes 
use \Sleepy\Core\Module;                            # to create a module

class Example2 extends Module
{
    public $hooks = [
        'render_placeholder_title' => 'addSite'     # We are going to use this filter -> method
    ];

    public function addSite($str)                   # The filter will get the value of the title placeholder as $str
    {
        return $str + ' | Website Name';            # and we return the modified string to the template for use
    }
}

Hook::register(new Example2());

The Module Class

Examples

Built-in Actions and Filters