Laravel背包select_multiple | select2_multple在以一对多关系进行更新/编辑时中断

Question

我认为使用BackpackCrudController更新（目标）模型时遇到了一个奇怪的错误/问题。

首先，我给您一些有关我的数据库结构和模型的信息。 （我忽略了无用的关系和功能）

快速了解我的composer.json

        "php": "^7.2",
        "backpack/crud": "4.0.*",
        "backpack/logmanager": "^3.0",
        "backpack/pagemanager": "^2.0",
        "backpack/permissionmanager": "^5.0",
        "fideloper/proxy": "^4.0",
        "laravel/framework": "^6.2",
        "laravel/tinker": "^2.0"

配方表：

        Schema::create('recipes', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->string('slug');
            $table->string('image');
            $table->text('content');
            $table->text('preparation');
            $table->json('ingredients');
            $table->integer( 'goal_id')->unsigned()->nullable();
            $table->integer( 'category_id')->unsigned()->nullable();
            $table->unsignedBigInteger( 'user_id');
            $table->timestamps();
        });

        Schema::table('recipes', function(Blueprint $table) {
            $table->foreign( 'goal_id')->references( 'id')->on('goals');
            $table->foreign( 'category_id')->references( 'id')->on('categories');
            $table->foreign( 'user_id')->references( 'id')->on('users');
        });

目标表：

       Schema::create('goals', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->string('slug');
            $table->string('image');
            $table->text( 'content');
            $table->string('workbook')->nullable();
            $table->tinyInteger('duration')->nullable();
            $table->timestamps();
        });

配方模型：

class Recipe extends Model
{
    use CrudTrait;
    use Sluggable;
    use SluggableScopeHelpers;

    /*
    |--------------------------------------------------------------------------
    | GLOBAL VARIABLES
    |--------------------------------------------------------------------------
    */

    protected $table = 'recipes';
    protected $guarded = ['id'];
    protected $fillable = ['title', 'slug', 'image', 'content', 'preparation', 'ingredients', 'goal_id', 'category_id', 'user_id'];


    /*
    |--------------------------------------------------------------------------
    | RELATIONS
    |--------------------------------------------------------------------------
    */
    public function goal(  ) {
        return $this->belongsTo( Goal::class);
    }
}

目标模式：

class Goal extends Model
{
    use CrudTrait;
    use Sluggable;
    use SluggableScopeHelpers;

    /*
    |--------------------------------------------------------------------------
    | GLOBAL VARIABLES
    |--------------------------------------------------------------------------
    */

    protected $table = 'goals';
    protected $guarded = ['id'];
    protected $fillable = ['title', 'slug', 'image', 'content', 'workbook', 'duration'];


    /*
    |--------------------------------------------------------------------------
    | RELATIONS
    |--------------------------------------------------------------------------
    */
    public function recipes(  ) {
        return $this->hasMany( Recipe::class,'goal_id', 'id');
    }
}

更新目标时存在问题，所以这是我的GoalCrudController：

class GoalCrudController extends CrudController
{
    use \Backpack\CRUD\app\Http\Controllers\Operations\ListOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\CreateOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\UpdateOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\DeleteOperation;
    use \Backpack\CRUD\app\Http\Controllers\Operations\ShowOperation;

    public function setup()
    {
        $this->crud->setModel('App\Models\Goal');
        $this->crud->setRoute(config('backpack.base.route_prefix') . '/goal');
        $this->crud->setEntityNameStrings('goal', 'goals');
    }

    protected function setupCreateOperation()
    {
        $this->crud->setValidation(GoalRequest::class);
        $this->crud->addField([
            'label'     => 'Articles',
            'type'      => 'select2_multiple',
            'name'      => 'articles',
            'entity'    => 'articles',
            'attribute' => 'title',
        ]);
        $this->crud->addField([
            'label'     => 'Recipes',
            'type'      => 'select2_multiple',
            'name'      => 'recipes',
            'entity'    => 'recipes',
            'attribute' => 'title',
        ]);
    }

    protected function setupUpdateOperation()
    {
        $this->setupCreateOperation();
        $this->crud->removeField('image');
        $this->crud->addField([
            'name'      => 'image',
            'label'     => 'Image',
            'type'      => 'image',
            'upload'    => true,
            'prefix'    => 'uploads/',
        ])->afterField('title');
    }
}

同样，我忽略了不适用于此问题的功能。

现在，问题是当我创建目标时，我可以附加一个配方（来自select2_multiple字段），并且将创建目标和配方之间的关系。但是，当我要编辑/更新刚创建的目标时，例如要添加新配方，我会收到以下异常：

Exception
Property [recipes] does not exist on this collection instance.

我已经尝试将setupUpdateOperation()中的字段编辑为以下内容：

        $this->crud->removeField('recipes');
        $this->crud->addField([
            'label'     => 'Recipes',
            'type'      => 'select2_multiple',
            'name'      => 'recipes',
            'entity'    => 'recipes',
            'attribute' => 'title',
            'value'     => Recipe::where('goal_id', $this->crud->getCurrentEntryId()), // <-- added this
        ]);

但是后来我得到以下异常：

Call to a member function pluck() on string (View: /Users/name/Docker/sitename/vendor/backpack/crud/src/resources/views/crud/fields/select_multiple.blade.php) // <-- at line 27

我的问题实际上是：

• 我将如何让用户更新现有目标以添加新目标食谱？
• 而且，创建时它如何工作，但当我创建要更新吗？
• 我使用select_multiple | select2_multiple在这种情况下不正确吗？
• 我的关系不正确吗？
• 我无法以这种方式保存关系吗？我是否需要从配方结尾开始？
• 我应该为更新操作使用其他选择字段还是model_function？

如果我需要提供更多信息，请告诉我，我们很乐意为您提供信息。预先感谢！

PS。使用select_multiple时，问题相同。

Answer 1

经过一番摆弄之后，我设法找到了解决方法。

在setupUpdateOperation功能中，我添加了以下内容：

$this->crud->removeField('recipes'); // remove the original field
$this->crud->addField([
            'label'     => 'Recipes',
            'type'      => 'select2_multiple',
            'name'      => 'recipes',
            'entity'    => 'recipes',
            'attribute' => 'title',
            'value'     => $this->crud->getCurrentEntry()->recipes,
        ]);

通过此操作，我设法在更新视图中获取了当前相关的食谱，并实际上更新了相关的食谱。