In a Laravel app, you may want to assign users to tasks while also tracking who assigned each user to a task. By utilizing Laravel's model events on pivot tables, this is easily achievable.

To begin, create three tables. One for tasks, one for users, and one for assigning users to tasks: task_user. Then, create the corresponding TaskUser pivot model using the following command:

php artisan make:model TaskUser --pivot

Next, add event handlers to the TaskUser model by adding the following code:

class TaskUser extends Pivot
{
    protected static function booted()
    {
        static::creating(function ($pivot_model) {
            // ...
        });
        // + any other event handler
    }
}

Now, it's important to let Laravel know which model it should use for the pivot table. This is achieved by adding the following code to the User model:

public function tasks()
{
    return $this->belongsToMany(Task::class)
      ->using(TaskUser::class);
}

Finally, you can assign users to tasks using the attach method on the user's tasks relationship, like so:

$user->tasks()->attach($tasks);

With these steps, your event callbacks or corresponding observer methods will be executed as expected. You now have a fully functional way to assign users to tasks while also tracking who assigned them.