Touch parent updated_at easily in Laravel
When a model belongsTo or belongsToMany another model, such as a Comment which belongs to a Post, it is sometimes helpful to update the parent's timestamp when the child model is updated. For example, when a Comment model is updated, you may want to automatically "touch" the updated_at timestamp of the owning Post. Eloquent makes it easy. Just add a touches property containing the names of the relationships to the child model:
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Comment extends Model
{
/**
* All of the relationships to be touched.
*
* @var array
*/
protected $touches = ['post'];
/**
* Get the post that the comment belongs to.
*/
public function post()
{
return $this->belongsTo('App\Models\Post');
}
}
Now, when you update a Comment, the owning Post will have its updated_at column updated as well, making it more convenient to know when to invalidate a cache of the Post model:
$comment = App\Models\Comment::find(1);
$comment->text = 'Edit to this comment!';
$comment->save();
