ed-fruty/strange-observer

JFF php objects observer

Strange PHP observer (JFF)

Sometimes we need to listen class calling actions, but for example we haven't permissions to edit it., _(*1)

Sometimes we have some instance of class only and we can't extend this class. (For example Database class. Instance was created and if we try to create new extend instance - new connection will be created. Or class can be final etc.), _(*2)

But functional of this class does not satisfy to our needs., _(*3)

For such cases you can use this strange observer ;), _(*4)

Installation

Install package via composer, _(*5)

bash composer require "ed-fruty/strange-php-observer": "1.0.0", _(*6)

Usage

For example we have class User with method register($attributes) and we want to add listeners for this method, _(*7)

```php <?php, <sub>(*8)</sub>

use Fruty\Observe\Manager; use Fruty\Observe\Event;, <sub>(*9)</sub>

class User extends SomeClass { /** * @access public * @param array $attributes * @return bool */ public function register(array $attributes) { return $this->save($attributes); } }, <sub>(*10)</sub>

// create instance $user = Manager::make('User');, <sub>(*11)</sub>

// or we can use instance of User extend of class name $instance = new User(); $user = Manager::make($instance);, <sub>(*12)</sub>

``` All done! We can use $user as previously, <sub>(*13)</sub>

php $user->register(array('username' => 'root')); Ok, now we want to add validation before register, <sub>(*14)</sub>

```php $user()->before('register', function(Event $event) { // validate data // get method arguments $params = $event->getParams();, <sub>(*15)</sub>

//... some validation logic

// for abort calling register method (if validation is failed) use
$event->stopPropagation();

// for setting some return value
$event->setResult("Validation errors");

}); ```, <sub>(*16)</sub>

And we want to send email when registration was successfull, <sub>(*17)</sub>

```php $user()->after('register', function(Event $event) { if ($event->getResult()) { // in $event->getResult() result of executed method, in our case it is boolean // and if it true - registration was successfull, so send email $email = $event->getParams()[0]['email']; $mailer = new Mailer(); $mailer->body("Congratulations!") ->to($email) ->send(); } });, <sub>(*18)</sub>

```, <sub>(*19)</sub>

Now we can use, <sub>(*20)</sub>

php $user->register(array('username' => 'root', 'email' => 'root@iam.com'));, <sub>(*21)</sub>

and before regitration will execute validaion, and after - sending email., <sub>(*22)</sub>

We can set priorities to the listeners, <sub>(*23)</sub>

```php, <sub>(*24)</sub>

$user()->before('register', function(Event $event) { // this code will be executed early than validation // because it have higher priority (Event::PRIORITY_HIGH) }, Event::PRIORITY_HIGH);, <sub>(*25)</sub>

```, <sub>(*26)</sub>

Also, we can bind new methods dynamically to the $user, <sub>(*27)</sub>

```php, <sub>(*28)</sub>

$user()->bind('updateLastLoginTime', function($userId) { //code });, <sub>(*29)</sub>

$user->updateLastLoginTime(5); ```, <sub>(*30)</sub>

We can redefine existing methods, <sub>(*31)</sub>

```php, <sub>(*32)</sub>

$user()->bind('register', function(array $attributes, $setAdminStatus) { if ($setAdminStatus) { $attributes['admin'] = true; } // call parent method return $this(true)->register($attributes); });, <sub>(*33)</sub>

$user->register(array('username' => 'root', 'email' => 'root@iam.com'), true); ```, <sub>(*34)</sub>

As you can see, in the code we uses 3 types of calling methods 1. $user->method() 2. $user()->method() 3. $user(true)->method(), <sub>(*35)</sub>

• $user is instanece of Invoker class and call $user->method() remap to the real instance of User class and can be listened
• $user(true) is real instance of User, calling $user(true)->method() can not be listened

• $user() is instance of observer to adding new listeners, binding new methods So, when you bind method, <sub>(*36)</sub>

  $user()->bind('getOne', function($userId)
  {
  //$this is instance of Invoker, methods will remap to the instance of User and they can be listened
  //$this(true) is instance of User, methods cannot be listened
  
  // NOTE!!!
  // if you write here $this->getOne() script will call this action again and again, so you must to use 
  // $this(true)->getOne() to use real User::getOne()
  
  // if you call here
  $this->register(); // it will be called and listened
  $this(true)->register(); // it will be called but not listened, this is original User::register()
  $this->updateLastLoginTime(); // it will be called and listened
  $this(true)->updateLastLoginTime(); // Fatal error, calling undefined method User::updateLastLoginTime()
  
  return array('some data');
  });
  
  

  We can add subscriber to the $user calls, <sub>(*37)</sub>

  use Fruty\Observe\Event;
  use Fruty\Observe\AbstractSubscriber;
  
  class UserSubscriber extends AbstractSubscriber
  {
  /**
   * This method will call before calling User::register()
   *
   * @access public
   * @static 
   * @param \Fruty\Observe\Event $event
   */
  public static function onBeforeRegister(Event $event)
  {
    // here code
  }
  
  /**
   * This method will call after calling User::register()
   *
   * @access public
   * @static 
   * @param \Fruty\Observe\Event $event
   */
  public static function onAfterRegister(Event $event)
  {
    // here code
  }
  
  /**
   * We can set priorities to the actions
   *
   * @access public
   * @static
   * @return array
   */
   public function getPriorities()
   {
    return array(
      'onBeforeRegister' => Event::PRIORITY_HIGHT,
      'onAfterRegiter' => Event::PRIORITY_LOW,
    );
   }
  }
  
  // register subscriber
  $user()->subscribe('UserSubscriber');
  
  

  How to check instance ?, <sub>(*38)</sub>

  ```php, <sub>(*39)</sub>

  if ($user instanceof User === true) { // Fail. $user is instance of Fruty\Observe\Invoker }, <sub>(*40)</sub>

  if ($user(true) instanceof User) { // Success }, <sub>(*41)</sub>