Level 122
Does this help? https://tighten.co/blog/laravel-tip-bootable-model-traits
Aug 16, 2019
8
Level 16
How to add observable events and use in an observer
TL;DR - How do I register custom observable events from a trait and observe those from another via an observer instance?
I created a global scope, called CancellingScope. Analogous to how soft deleting works, but it is intended for regular users instead of users with elevated access.
I need to be able to listen to the cancelled event via a model observer to remove it from the Elastic Search index because I do not want people to be able to search for cancelled entities.
I examined the HasEvents trait and it exposes a class method called addObservableEvents. The problem is that this is a class method, not static and typically in a trait you register model observers statically, like so:
public static function bootTrait()
{
static::observe(new ModelObserver);
}
-
I tried using a class method with the initialize prefix, but those methods are executed after the booting ones, so when it is way too late.
-
I looked at how soft deleting does this, but apparently it's just a hard-coded array and does not use the addObservableEvents method. I tried overloading the $observables property, with no avail (throws exception).
Basically, what I want to achieve:
- Add custom (observable) events via Cancels.php (trait)
- Register observer that listens to those events via Searchable.php (trait)
Could anyone help me out with this? Thanks in advance.
Level 16
Thanks for the link. Unfortunately, it does not as those are things that I already knew.
My main problem is adding "custom" events to the $observables property of the HasEvents trait before the boot methods are run so that the event observer's methods are properly registered. It does not register "unknown" events so even if I have a cancelled function in an observer, it is straight up ignored.
Level 16
I have tried the following:
protected $observables = [
'cancelling',
'cancelled',
'uncancelling',
'uncancelled',
];
But then, I receive the error below (which is logical): Illuminate\Database\Eloquent\Model and App\Models\Traits\Cancels define the same property ($observables) in the composition of App\Models\Entity. However, the definition differs and is considered incompatible.
I have two solutions, but neither of them make me happy:
- Defining the observable events in each model that is cancellable (not DRY)
- Overriding getObservableEvents in Cancels trait like so:
public function getObservableEvents()
{
return array_merge($this->observables, [
'retrieved', 'creating', 'created', 'updating', 'updated',
'saving', 'saved', 'restoring', 'restored', 'replicating',
'deleting', 'deleted', 'forceDeleted',
'cancelling', 'cancelled', 'uncancelling', 'uncancelled',
]);
}
Both of them are "meh" solutions, repetitive/hacky. There must be a proper way to populate the $observables property in the trait itself... (before the boot methods are run)
1 like
Level 16
Bumping as this is still an issue. Currently working it around by overriding getObservableEvents, but it is hacky.
Level 1
Hi @mabdullahsari. You can add a non-static function initialize to your trait which will be called from the constructor of model classes that use your trait. In that method you can call $this->addObservableEvents.
1 like
Level 16
@petercv I don't know why you decided to gravedig, but I've explicitly stated the following...
I tried using a class method with the initialize prefix, but those methods are executed after the booting ones, so when it is way too late.
Level 1
@petercv is right. Adding it in initialize{TraitName} works. Example:
trait Archivable
{
/**
* Initialize Model Hook
*
* Adds our custom model events
*/
public function initializeArchivable()
{
$this->addObservableEvents([
'archiving',
'archived',
'unarchiving',
'unarchived'
]);
debug($this->observables);
}
// etc
}
1 like
Level 16
No. Can you read?
1 like
Please or to participate in this conversation.