如何在 Laravel 中保存多对多多态关系中的条目？

Question

我有一个 Org 模型和一个 Tag 模型。我想将标签与组织相关联。我的数据库表和 Eloquent 模型是这样设置的......

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');
    }
}

在我看来，我有一个带有多选框的表单，用户可以在其中选择他/她想要与组织关联的标签...

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

... $tag_options 来自我的 routes.php 文件...

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);
});

当我视图中的表单被提交时，下面的路由会捕获它来更新组织模型...

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!');
});

现在，Input::get('tags') 只是一个标签 ID 的数组，格式为

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

如何使用它来将标签与组织相关联？

我还为使用多态关系的组织设置了 cmets，我只是这样做...

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!');
});

但是，当我想将一个或多个标签与组织相关联时，多对多的多态关系并不那么简单。

感谢任何帮助，谢谢！

Answer 1

您可以为此使用所有 belongsToMany 方法，因为多态多对多扩展了该关系：

// 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)

当然，所有这些方法都是双向的。

---

示例：

$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

---

你的情况：

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!');
});