How to save entries in many to many polymorphic relationship in Laravel

eloquentlaravel-4polymorphic-associations

I have an Org model and a Tag model. I want to associate tags with organizations. My database tables and Eloquent models are set up like so …

org
    id - integer
    name - string
    ...

tags
    id - integer
    name - string

taggables
    id - integer
    taggable_id - integer
    taggable_type - string

// app/models/Org.php
class Org extends Eloquent
{
    protected $table = "org";

    ...

    public function tags()
    {
        return $this->morphToMany('Tag', 'taggable');
    }
}

// app/models/Tag.php
class Tag extends Eloquent
{
    protected $table = "tags";
    public $timestamps = false;

    public function org() 
    {
        return $this->morphedByMany('Org', 'taggable');
    }
}

In my view, I have a form with a multiple select box where the user can select the tags he/she wants to be associated with the organization …

...
{{ Form::select('tags[]', $tag_options, null, array(
        'multiple',
        'data-placeholder' => 'Select some tags'))
}}
...

… And $tag_options comes from my routes.php file …

View::composer('*', function($view)
{
    $tags = Tag::all();

    if(count($tags) > 0)
    {
        $tag_options = array_combine($tags->lists('id'),
                                    $tags->lists('name'));
    }
    else
    {
        $tag_options = array(null, 'Unspecified');
    }

    $view->with('tag_options', $tag_options);
});

When the form in my view is submitted, the following route will catch it to update the org model …

Route::put('org/{org}', function(Org $org){
    $org->description = Input::get('description');
    $org->website = Input::get('website');
    $org->tags = Input::get('tags');
    $org->save();

    return Redirect::to('org/'.$org->id)
        ->with('message', 'Seccessfully updated page!');
});

Now, Input::get('tags') is just an array of the tag IDs, of the form

["1","6","8"]

How can I use this to associate the tags with the organization?

I also have comments set up for organizations using a polymorphic relationship where I just do this …

Route::put('org/post/{org}', function(Org $org){
    $comment = new Comment;
    $comment->user_id = Auth::user()->id;
    $comment->body = Input::get('body');
    $comment->commentable_id = $org->id;
    $comment->commentable_type = 'Org';
    $comment->save();

    return Redirect::to('org/'.$org->id)
        ->with('message', 'Seccessfully posted comment!');
});

However, it's not as simple with a many-to-many polymorphic relationship when I want to associate one or more tags with an organization.

Any help is appreciated, thanks!!

Best Answer

You can use all of the belongsToMany methods for this, for polymorphic many-to-many extends that relation:

// I would call that relation on tag in plural 'entities()' to be more accurate

$tag->entities()->save(new or existing model, array of pivot data, touch parent = true) (used on existing model)
$tag->entities()->saveMany(array of new or existing models, array of arrays with pivot data)
$tag->entities()->attach(existing model / id, array of pivot data, touch parent = true)
$tag->entities()->sync(array of ids, detach = true)
$tag->entities()->updateExistingPivot(pivot id, array of pivot data, touch)

All of those methods work both ways of course.

Examples:

$tag = Tag::first();
$entity = Entity::find(10);

// save() works with both newly created and existing models:
$tag->entities()->save(new Entity(...));
$tag->entities()->save($entity);

// saveMany() like above works with new and/or existing models:
$tag->entities()->saveMany([$entity, new Entity(...)]);

// attach() works with existing model or its id:
$tag->entities()->attach($entity);
$tag->entities()->attach($entity->id);

// sync() works with existing models' ids:
$tag->entities()->sync([1,5,10]); // detaches all previous relations
$tag->entities()->sync([1,5,10], false); // does not detach previous relations, attaches new ones skipping existing ids

Your case:

Route::put('org/{org}', function(Org $org){

  $org->description = Input::get('description');
  $org->website = Input::get('website');
  $org->save();

  $org->tags()->sync(Input::get('tags'));

  // or if you don't want to detach previous tags:
  // $org->tags()->sync(Input::get('tags'), false);


  return Redirect::to('org/'.$org->id)
    ->with('message', 'Seccessfully updated page!');
});
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