删除帖子时如何删除laravel中的所有相关评论，喜欢和通知

Question

I want to delete all related data when I delete a post. All comments likes and all notifications related to this post are also deleted when I delete this post. How can I do this ? I do that when a user delets all his posts, buckets, comments, and reported users is also deleted. Here is the Code of this. But i also want to delete all the things related to the post like notifications, likes etc. Please help.

public function destroy($id)
{
    $user = User::find($id);

    $user->posts()->forceDelete();
    $user->buckets()->forceDelete();
    $user->comments()->forceDelete();
    $user->reportedUser()->forceDelete();

    $user->forceDelete();

    return redirect()->route('users.index')->with('Success','User Deleted Successfully');
}

This code delete all the things that relates to user when user is deleted but i also want to delete all things related to post. How i can do this?

Answer 1

You can model events to trigger off an action once the Post record is being deleted. In your Post model, you can add a $dispatchesEvents property:

protected $dispatchesEvents = [
    'deleting' => \App\Events\PostDeleting::class,
];

After this, you can create the new event:

php artisan make:event PostDeleting

A new event file should be added ( app\\events\\PostDeleting.php ).

Here you can define the data which will be passed to the event listener.

<?php

namespace App\Events;

use App\Post;
use Illuminate\Queue\SerializesModels;

class PostDeleting
{
    use SerializesModels;

    public $post;

    /**
     * Create a new event instance.
     *
     * @param \App\Post $post
     */
    public function __construct(Post $post)
    {
        $this->post = $post;
    }
}

After this, you will need to create the event listener (which will listen out for the post being deleted):

php artisan event:listener PostDeleting

This will create a listener ( app/listeners/PostDeleting.php ). Here, you define the functionality which is ran once the Post is deleting (this uses the variable defined in the event :

<?php

namespace App\Listeners;

use App\Events\PostDeleting as PostDeletingEvent;

class PostDeleting
{
    /**
     * Handle the event.
     *
     * @param  \App\Events\PostDeleting $event
     * @return mixed
     */
    public function handle(PostDeletingEvent $event)
    {
        $event->user->likes()->delete(); // or whatever relation you need to delete.
    }
}

Answer 2

You can set in your migrations

Eg comments migration

$table->foreign('post_id')
      ->references('id')
      ->on('posts')
      ->onDelete('cascade');

No need to write any other logic. you can write something like that on your relational migration

For polymorphic relationship Eg

Post Model

protected static function boot()
{
    parent::boot();

    static::deleting(function ($post) {
        $post->comments()->delete();
        // ...
    });

}

or You can manage by Cascade polymorphic delete package