Laravel 5.4 Relations are not loading inside Model boot method - php

Question

I have a model named 'Poll'. Inside Poll model I defined a boot method like follows:
public static function boot()
{
parent::boot();
self::created(function($model){
// dd($model);
$speakers = $model->speakers()->get();
// dd($speakers);
// What I want to do here is: create poll options relation from speakers as follows
// $poll->poll_options()->create([
// 'option' => $speaker->name,
// ]);
}
}
I am adding the speakers relation and it is working perfect.
But inside this boot method, inside self::created if I tried to get the speakers relation, it is always empty (dd($speakers) line). Is it because of the boot method runs just after the model is saved into DB and the relations not at all saved?
I am getting newly created model in the line: dd($model) mentioned in the code.
UPDATE
I tried with events also.
My Poll Model:
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
use Backpack\CRUD\CrudTrait;
use Cookie;
use App\Events\PollCreated;
class Poll extends Model
{
........
protected $events = [
'created' => PollCreated::class,
];
.......
public function speakers()
{
return $this->belongsToMany('App\Models\Speaker','poll_speaker','poll_id','speaker_id');
}
}
app/Events/PollCreated.php:
namespace App\Events;
use App\Models\Poll;
use Illuminate\Queue\SerializesModels;
class PollCreated
{
use SerializesModels;
public $poll;
/**
* Create a new event instance.
*
* #param Poll $poll
* #return void
*/
public function __construct(Poll $poll)
{
// $this->poll = $poll;
$event = $poll->event()->first();
// dd($event);
// dd($poll->speakers()->get());
// dd($poll->load('speakers'));
}
}
Here also I am not getting speakers, in the line: dd($poll->speakers()->get());
my Speaker model:
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
use Backpack\CRUD\CrudTrait;
class Speaker extends Model
{
use CrudTrait;
……..
public function polls()
{
return $this->belongsToMany('App\Models\Poll');
}
……..
}

Answer 1

The problem is with timing as models must always be created before they can be set in a many-to-many relationship. So there is no possible way that in a many-to-many relationship during the created event the relationship is already set as the created events are always raised before the relationships.
Anyone looking for a solution can probably experiment with the chelout/laravel-relationship-events package as this adds relationship events to models.
To be sure, I tested this out with a simple application of users and computers.
User.php
class User extends Model
{
use HasBelongsToManyEvents;
public static function boot() {
parent::boot();
self::created(function($model){
Log::info('user::created');
});
static::belongsToManyAttaching(function ($relation, $parent, $ids) {
$ids = implode(' & ', $ids);
Log::info("Attaching {$relation} {$ids} to user.");
});
static::belongsToManyAttached(function ($relation, $parent, $ids) {
$ids = implode(' & ', $ids);
Log::info("Computers {$ids} have been attached to user.");
});
}
public function computers() {
return $this->belongsToMany(Computer::class, 'user_computers');
}
}
Computer class is the same in reverse. And for the following code:
$user = User::create();
$user->computers()->attach([
Computer::create()->id,
Computer::create()->id
]);
This was the outcome:
user::created
computer::created
computer::created
Attaching computers 69 & 70 to user.
Computers 69 & 70 have been attached to user.