Many-To-Many Relationship in backpack 4.1 for laravel

Question

I use laravel 8 and backpack 4.1 for laravel. I have to add in one column more then one comma-separated-values. I have one pivot table with 2 foreign keys. The user can see with foreign key the available objects. I have to put all available objects into one column in setupListOperation() in CrudController of the user. How can I do it? UserModel:

public function Objects(): belongsToMany
{
    return $this->belongsToMany(Object::class);
}



CRUD::column('object_id')
        ->type('relationship')
        ->relation_type('BelongsToMany')
        ->model(Object::class)
        ->entity('name')
        ->label('Objects');

Thank you for your answers in advance.

score 2 · Answer 1 · answered Jun 22 '22 at 08:28

I have found another method for the user crud. This method supposed to get the values from the method of the model.

  $this->crud->addColumn(
            [
                // run a function on the CRUD model and show its return value
                'name'  => 'rentalObjects',
                'label' => 'RentalObjects', // Table column heading
                'type'  => 'model_function_attribute',
                'function_name' => 'getRentalObjects',
                'attribute' => 'name'
            ]);

Method in the model User:

 public function getRentalObjects(): string
    {
        $users = User::all();
        foreach ($users as $user) {
            $rentalObjects = $user->rentalObjects;
            foreach ($rentalObjects as $rentalObject) {
                $objectsNames = $rentalObject->name;
            }
            $objects = implode(",", array($objectsNames));
        }
        return $objects;
    }

score 0 · Answer 2 · answered Jun 22 '22 at 14:53

I coudn't see the new column on the small screen und thought, that the column wasn't in the table. By backpack one can choose the columns, if the screen is small. The problem was solved:

$this->crud->addColumn([
            'label'     => 'Objekte', // Table column heading
            'type'      => 'select_multiple',
            'name'      => 'rentalObjects', // the method that defines the relationship in your Model
            'entity'    => 'rentalObjects', // the method that defines the relationship in your Model
            'attribute' => 'name', // foreign key attribute that is shown to user
            'model'     => 'App\Models\RentalObject', // foreign key model
        ]);

Many-To-Many Relationship in backpack 4.1 for laravel

2 Answers2