<?php
namespace Illuminate\Database\Eloquent\Concerns;
use Illuminate\Contracts\Events\Dispatcher;
use Illuminate\Events\NullDispatcher;
use Illuminate\Support\Arr;
use InvalidArgumentException;
trait HasEvents
{
/**
* The event map for the model.
*
* Allows for object-based events for native Eloquent events.
*
* @var array
*/
protected $dispatchesEvents = [];
/**
* User exposed observable events.
*
* These are extra user-defined events observers may subscribe to.
*
* @var array
*/
protected $observables = [];
/**
* Register observers with the model.
*
* @param object|array|string $classes
* @return void
*
* @throws \RuntimeException
*/
public static function observe($classes)
{
$instance = new static;
foreach (Arr::wrap($classes) as $class) {
$instance->registerObserver($class);
}
}
/**
* Register a single observer with the model.
*
* @param object|string $class
* @return void
*
* @throws \RuntimeException
*/
protected function registerObserver($class)
{
$className = $this->resolveObserverClassName($class);
// When registering a model observer, we will spin through the possible events
// and determine if this observer has that method. If it does, we will hook
// it into the model's event system, making it convenient to watch these.
foreach ($this->getObservableEvents() as $event) {
if (method_exists($class, $event)) {
static::registerModelEvent($event, $className.'@'.$event);
}
}
}
/**
* Resolve the observer's class name from an object or string.
*
* @param object|string $class
* @return string
*
* @throws \InvalidArgumentException
*/
private function resolveObserverClassName($class)
{
if (is_object($class)) {
return get_class($class);
}
if (class_exists($class)) {
return $class;
}
throw new InvalidArgumentException('Unable to find observer: '.$class);
}
/**
* Get the observable event names.
*
* @return array
*/
public function getObservableEvents()
{
return array_merge(
[
'retrieved', 'creating', 'created', 'updating', 'updated',
'saving', 'saved', 'restoring', 'restored', 'replicating',
'deleting', 'deleted', 'forceDeleted',
],
$this->observables
);
}
/**
* Set the observable event names.
*
* @param array $observables
* @return $this
*/
public function setObservableEvents(array $observables)
{
$this->observables = $observables;
return $this;
}
/**
* Add an observable event name.
*
* @param array|mixed $observables
* @return void
*/
public function addObservableEvents($observables)
{
$this->observables = array_unique(array_merge(
$this->observables, is_array($observables) ? $observables : func_get_args()
));
}
/**
* Remove an observable event name.
*
* @param array|mixed $observables
* @return void
*/
public function removeObservableEvents($observables)
{
$this->observables = array_diff(
$this->observables, is_array($observables) ? $observables : func_get_args()
);
}
/**
* Register a model event with the dispatcher.
*
* @param string $event
* @param \Closure|string $callback
* @return void
*/
protected static function registerModelEvent($event, $callback)
{
if (isset(static::$dispatcher)) {
$name = static::class;
static::$dispatcher->listen("eloquent.{$event}: {$name}", $callback);
}
}
/**
* Fire the given event for the model.
*
* @param string $event
* @param bool $halt
* @return mixed
*/
protected function fireModelEvent($event, $halt = true)
{
if (! isset(static::$dispatcher)) {
return true;
}
// First, we will get the proper method to call on the event dispatcher, and then we
// will attempt to fire a custom, object based event for the given event. If that
// returns a result we can return that result, or we'll call the string events.
$method = $halt ? 'until' : 'dispatch';
$result = $this->filterModelEventResults(
$this->fireCustomModelEvent($event, $method)
);
if ($result === false) {
return false;
}
return ! empty($result) ? $result : static::$dispatcher->{$method}(
"eloquent.{$event}: ".static::class, $this
);
}
/**
* Fire a custom model event for the given event.
*
* @param string $event
* @param string $method
* @return mixed|null
*/
protected function fireCustomModelEvent($event, $method)
{
if (! isset($this->dispatchesEvents[$event])) {
return;
}
$result = static::$dispatcher->$method(new $this->dispatchesEvents[$event]($this));
if (! is_null($result)) {
return $result;
}
}
/**
* Filter the model event results.
*
* @param mixed $result
* @return mixed
*/
protected function filterModelEventResults($result)
{
if (is_array($result)) {
$result = array_filter($result, function ($response) {
return ! is_null($response);
});
}
return $result;
}
/**
* Register a retrieved model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function retrieved($callback)
{
static::registerModelEvent('retrieved', $callback);
}
/**
* Register a saving model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function saving($callback)
{
static::registerModelEvent('saving', $callback);
}
/**
* Register a saved model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function saved($callback)
{
static::registerModelEvent('saved', $callback);
}
/**
* Register an updating model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function updating($callback)
{
static::registerModelEvent('updating', $callback);
}
/**
* Register an updated model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function updated($callback)
{
static::registerModelEvent('updated', $callback);
}
/**
* Register a creating model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function creating($callback)
{
static::registerModelEvent('creating', $callback);
}
/**
* Register a created model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function created($callback)
{
static::registerModelEvent('created', $callback);
}
/**
* Register a replicating model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function replicating($callback)
{
static::registerModelEvent('replicating', $callback);
}
/**
* Register a deleting model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function deleting($callback)
{
static::registerModelEvent('deleting', $callback);
}
/**
* Register a deleted model event with the dispatcher.
*
* @param \Closure|string $callback
* @return void
*/
public static function deleted($callback)
{
static::registerModelEvent('deleted', $callback);
}
/**
* Remove all of the event listeners for the model.
*
* @return void
*/
public static function flushEventListeners()
{
if (! isset(static::$dispatcher)) {
return;
}
$instance = new static;
foreach ($instance->getObservableEvents() as $event) {
static::$dispatcher->forget("eloquent.{$event}: ".static::class);
}
foreach (array_values($instance->dispatchesEvents) as $event) {
static::$dispatcher->forget($event);
}
}
/**
* Get the event dispatcher instance.
*
* @return \Illuminate\Contracts\Events\Dispatcher
*/
public static function getEventDispatcher()
{
return static::$dispatcher;
}
/**
* Set the event dispatcher instance.
*
* @param \Illuminate\Contracts\Events\Dispatcher $dispatcher
* @return void
*/
public static function setEventDispatcher(Dispatcher $dispatcher)
{
static::$dispatcher = $dispatcher;
}
/**
* Unset the event dispatcher for models.
*
* @return void
*/
public static function unsetEventDispatcher()
{
static::$dispatcher = null;
}
/**
* Execute a callback without firing any model events for any model type.
*
* @param callable $callback
* @return mixed
*/
public static function withoutEvents(callable $callback)
{
$dispatcher = static::getEventDispatcher();
if ($dispatcher) {
static::setEventDispatcher(new NullDispatcher($dispatcher));
}
try {
return $callback();
} finally {
if ($dispatcher) {
static::setEventDispatcher($dispatcher);
}
}
}
}