Eventos com Codeigniter 3

autoload.php

#vamos configurar nosso autoload da library Events;
#config/autload.php
<?php

/*
  | -------------------------------------------------------------------
  |  Auto-load Libraries
  | -------------------------------------------------------------------
  | These are the classes located in the system/libraries folder
  | or in your application/libraries folder.
  |
  | Prototype:
  |
  |	$autoload['libraries'] = array('database', 'session', 'xmlrpc');
 */  
$autoload['libraries'] = array('database', 'session', 'table','events');

composer.json

Adiocione esses linhas para seu arquivo.
Essa pasta será onde vamos adicionar nossos arquivos de eventos.
Isso é um pouco fora da curva do php mas tudo bem.

"autoload":{
    	"psr-4":{
    		    "Events\\":"application\\Events\\",
    	  }
}

Eventos com codeigniter

1 -Primeiro vamos dar uma olhada de como será nossa estrutura de pastas para isso.
2 -Vamos criar uma nova pasta dentro da nossa pasta aplicaction


--application
  -Events
  -core
  -config
  -controllers
  -models
  -libraries
  -hooks
  ...
  
  

Events.php

- Vamos criar o aquivo dentro de Libraries

<?php 

class Events {
	/**
	 * @var	array	An array of listeners
	 */
	protected static $_listeners = array();
	// ------------------------------------------------------------------------
	/**
	 * Register
	 *
	 * Registers a Callback for a given event
	 *
	 * @access	public
	 * @param	string	The name of the event
	 * @param	array	The callback for the Event
	 * @return	void
	 */
	public static function register($event, array $callback)
	{
		$key = get_class($callback[0]).'::'.$callback[1];
		self::$_listeners[$event][$key] = $callback;
		self::log_message('debug', 'Events::register() - Registered "'.$key.' with event "'.$event.'"');
	}
	// ------------------------------------------------------------------------
	/**
	 * Trigger
	 *
	 * Triggers an event and returns the results.  The results can be returned
	 * in the following formats:
	 *
	 * 'array'
	 * 'json'
	 * 'serialized'
	 * 'string'
	 *
	 * @access	public
	 * @param	string	The name of the event
	 * @param	mixed	Any data that is to be passed to the listener
	 * @param	string	The return type
	 * @return	mixed	The return of the listeners, in the return type
	 */
	public static function trigger($event, $data = '', $return_type = 'string')
	{
		self::log_message('debug', 'Events::trigger() - Triggering event "'.$event.'"');
		$calls = array();
		if (self::has_listeners($event))
		{
			foreach (self::$_listeners[$event] as $listener)
			{
				if (is_callable($listener))
				{
					$calls[] = call_user_func($listener, $data);
				}
			}
		}
		return self::_format_return($calls, $return_type);
	}
	// ------------------------------------------------------------------------
	/**
	 * Format Return
	 *
	 * Formats the return in the given type
	 *
	 * @access	protected
	 * @param	array	The array of returns
	 * @param	string	The return type
	 * @return	mixed	The formatted return
	 */
	protected static function _format_return(array $calls, $return_type)
	{
		self::log_message('debug', 'Events::_format_return() - Formating calls in type "'.$return_type.'"');
		switch ($return_type)
		{
			case 'json':
				return json_encode($calls);
				break;
			case 'serialized':
				return serialize($calls);
				break;
			case 'string':
				$str = '';
				foreach ($calls as $call)
				{
					$str .= $call;
				}
				return $str;
				break;
			default:
				return $calls;
				break;
		}
		return FALSE;
	}
	// ------------------------------------------------------------------------
	/**
	 * Has Listeners
	 *
	 * Checks if the event has listeners
	 *
	 * @access	public
	 * @param	string	The name of the event
	 * @return	bool	Whether the event has listeners
	 */
	public static function has_listeners($event)
	{
		self::log_message('debug', 'Events::has_listeners() - Checking if event "'.$event.'" has listeners.');
		if (isset(self::$_listeners[$event]) AND count(self::$_listeners[$event]) > 0)
		{
			return TRUE;
		}
		return FALSE;
	}
	// ------------------------------------------------------------------------
	/**
	 * Log Message
	 *
	 * Pulled out for unit testing
	 *
	 * @param string $type
	 * @param string $message
	 * @return void
	 */
	public static function log_message($type = 'debug', $message = '')
	{
		if (function_exists('log_message'))
		{
			log_message($type, $message);
		}
	}
}


//** libraries/Events

hooks.php

E por ultimo nosso arquivo hooks.php
E não vamos esquecer de habilitar hooks em config.php
<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/*
| -------------------------------------------------------------------------
| Hooks
| -------------------------------------------------------------------------
| This file lets you define "hooks" to extend CI without hacking the core
| files.  Please see the user guide for info:
|
|	http://codeigniter.com/user_guide/general/hooks.html
| 
|
*/


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

Nosso_Controller.php

<?php 

class Register extends CI_Controller{
  
  
   
  public function create(){
    
    $this->load->view('user/create');
  }
  
  public function store(){
    
    $data = $this->input->post();
    if($this->db->insert('user', $data))
       Events::trigger('user:create' , $data);
    
  }
}

register_events.php

Agora vamos criar um arquivo onde vamos centralizar todos os registros dos nossos eventos.
<?php 

$config = [
   'user:create' => [
        Events\RegisterUserSMSEvent::class,
        Events\RegisterUserMailerEvent::class  
   ],
   'user:update' => [
        Events\RegisterUserMailerEvent::class  
   ],
   'user:delete' => [
        Events\RegisterUserSMSEvent::class,
        Events\RegisterUserMailerEvent::class 
   ]

];





return $config;
//** config/register_events.php

RegisterEventAutoload.php

Vamos adicionar esse nosso arquivo na pasta hooks
<?php 
//application/hooks


class RegisterEventAutoload{

    

    
    /**
     * [handler on start classe events
     * @return [type] [description]
     */
    public function handler(){

       
       $ci  = get_instance();
       	$ci->load->config('register_events', true);
        $registered = config_item('register_events');

        if(! $registered) return;

        $this->registerAllEvents($registered);
         
       
    }


    /**
     * [registerAllEvents description]
     * @param  [type] $events [description]
     * @return [type]         [description]
     */
    private function registerAllEvents($events){
          
          foreach ($events as $key => $ev) {

          	         foreach ($ev as  $classEvent) {
          	         	    if(!is_object($classEvent))
          	         	    	 $classEvent = new $classEvent();

          	         	     Events::register($key , [$classEvent , 'handler']);	 
          	         }
          	   
          }
    }


}

//** hooks/RegisterEventAutoload.php

RegisterUserMailerEvent.php

<?php 

namespace Events;

class RegisterUserMailerEvent {
  
  
  
  public function handler($data){
    //script para enviar e-mail.
    
     if( mailer()->send($data))
        return true;
        user
        return false;
  }  
  
  
  
}
//** Events\RegisterUserMailerEvent.php

RegisterUserSMSEvent.php

<?php 

namespace Events;

class RegisterUserSMSEvent {
  
  
  
  public function handler($data){
    //script para enviar sms
    
     if(sms()->send($data))
        return true;
        
        
        return false;
  }  
  
  
  
}
//** Events\RegisterUserSMSEvent.php

Usando Composer

1 - Vamos fazer uso da psr-4, então vamos precisar configurar nosso composer 
2 - Vamos configurar um projeto em composer caso você não tenha instalado o projeto usando o composer.
3 - Vamos configurar nosso composer autoload  em application/config/config.php ['composer_autolaod'] configurar para suas configurações;
4 - agora precisamos configurar nosso composer.json