Field select2_multiple problems when using Laravel 5.2 Model with custom Join/Pivot Table

Hey, I might be using this wrong… but I didn’t see in documentation where to get this to work. Documentation: https://laravel-backpack.readme.io/docs/crud-fields#select2_multiple-n-n-relationship I’m using a custom Pivot Table for many-to-many relationship (https://laravel.com/docs/5.2/eloquent-relationships#many-to-many).

Challenge.php model:

...
    public function teams()
    {
        return $this->belongsToMany('App\Team', 'challenge_team', 'challenge_id', 'team_id')->withTimestamps();
    }
...

_ChallengeCrudController.php :_

...
        $this->crud->addField(
            [       // Select2Multiple = n-n relationship (with pivot table)
                'label' => "Teams Involved",
                'type' => 'select2_multiple',
                'name' => 'teams', // the method that defines the relationship in your Model
                'entity' => 'teams', // the method that defines the relationship in your Model
                'attribute' => 'team_name', // foreign key attribute that is shown to user
                'model' => "App\Team", // foreign key model
                'pivot' => true, // on create&update, do you need to add/delete pivot table entries?
            ]
        );
...

Doing this… I was able to select and SAVE NEW Challenges with multiple Teams, but I was unable to EDIT and see the previously selected Teams. It did persist to database… but didn’t render them in view properly.

I did the following to make it work: _ChallengeCrudController.php :_

...
        $this->crud->addField(
            [       // Select2Multiple = n-n relationship (with pivot table)
                'label' => "Teams Involved",
                'type' => 'select2_multiple',
                'name' => 'teams', // the method that defines the relationship in your Model
                'entity' => 'teams', // the method that defines the relationship in your Model
                'attribute' => 'team_name', // foreign key attribute that is shown to user
                'model' => "App\Team", // foreign key model
                'pivot' => true, // on create&update, do you need to add/delete pivot table entries?
                'foreign_pivot_key' => 'team_id'
            ]
        );
...

Then added the foreign_pivot_key to select2_multiple.blade.php file:

...
<!-- select2 multiple -->
<div class="form-group">
    <label>{{ $field['label'] }}</label>
    <?php
    $field['foreign_pivot_key'] = !empty($field['foreign_pivot_key']) ? $field['foreign_pivot_key'] : 'id';
    ?>
    <select
        class="form-control select2"

    @foreach ($field as $attribute => $value)
        @if (is_string($attribute))
            @if ($attribute=='name')
                {{ $attribute }}="{{ $value }}[]"
            @else
                {{ $attribute }}="{{ $value }}"
            @endif
        @endif
    @endforeach
    multiple>
    <option value="">-</option>

    @if (isset($field['model']))
        @foreach ($field['model']::all() as $connected_entity_entry)
            <option value="{{ $connected_entity_entry->getKey() }}"
                    @if ( (isset($field['value']) && in_array($connected_entity_entry->getKey(), $field['value']->lists($field['foreign_pivot_key'])->toArray())) || ( old( $field["name"] ) && in_array($connected_entity_entry->getKey(), old( $field["name"])) ) )
                    selected
                @endif
            >{{ $connected_entity_entry->{$field['attribute']} }}</option>
            @endforeach
            @endif
            </select>
</div>
...

Let me know if that’s a good work-around.

LOVE THE BACKPACK packages!!!

[pxpm]

@LinLin520 shouldn’t you alse set pivot => true in field definition ?

[BinaryBlock]

Could you please try it when you have the time and tell me if it works for you too? If so, I’ll push the update immediately.

Ahhh… you rock! Yes, it worked great. Smart idea about grabbing pivot info from object. Push away.