Yii2在gridview中获取多对多关系的数据并应用过滤器

Question

i'm developing a web application with Yii2 framework, and i'm facing a problem right now. I want to display the data from a many-to-many relation in a gridview and be able to filter from those fields later on.

I've read the official documentation here, some stackoverflow post like this and other resources but can't seem to get it to work. I have 3 tables: actividad, plan_actividad and circulo_icare, actividad is related to plan_actividad and circulo_icare is also related to it (plan_actividad is the junction table). So i have defined the following relations in my Actividad model:

class Actividad extends \yii\db\ActiveRecord 
{
   .... 

public function getPlanActividad()
{
    return $this->hasMany(PlanActividad::classname(), ['act_id' => 'act_id']);
}

public function getCirculo()
{
    return $this->hasMany(CirculoIcare::classname(), ['cirica_id' => 'act_id'])->via('planActividad');
}

...
}

The in my view index.php i'm trying to show the values in a gridview like this:

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    // 'filterModel' => $searchModel,
    'columns' => [
        ['class' => 'yii\grid\SerialColumn'],

        // 'act_id',
        ['attribute' => 'Codigo Evento', 'value' => 'act_numorden'],
        ['attribute' => 'Nombre Evento', 'value' => 'act_nombre'],
        ['attribute' => 'Fecha Evento', 'value' => 'act_fecha'],
        ['attribute' => 'Locacion', 'value' => 'locacion.loc_nombre'],
        [
        'attribute' => 'Circulo',
        'value' => 'circulo.cirica_nombre',

        ],
        ['attribute' => 'Circulo id',
         'value' => 'planActividad.cirica_id',
        ],
        // 'act_horaini',
        // 'act_horafin',
        // 'act_idencuesta',
        // 'act_vigencia:boolean',
        // 'loc_id',

        ['class' => 'yii\grid\ActionColumn'],
    ],
]); ?>

The problem is, i can't get any values to show with the circulo relation, it always shows (not set). If i change hasMany in getPlanActividad() with hasOne() then it shows some values (only 2 of 11 it should, based on the cirica_id that exist on plan_actividad table) but these are not correct anyway. I know that i can filter for those fields later on in search view but i don't really understand why the relations doesn't work as i expected.

Any help would be greatly appreciated, let me know if more info is needed and thank you in advance.

Answer 1

Answering my own question (credits to softark from the yii official forums).

In order for the relation to work as expected, I had to change:

public function getCirculos()
{
     return $this->hasMany(CirculoIcare::classname(), ['cirica_id' => 'act_id'])->via('planActividad');
}

to

public function getCirculos()
{
     return $this->hasMany(CirculoIcare::classname(), ['cirica_id' => 'cirica_id'])->via('planActividad');
}

and use a callback function in the gridview to display the correct values, since a hasMany relation gives an array of models and not a single model. So I modified the gridview code to:

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    // 'filterModel' => $searchModel,
    'columns' => [
        ['class' => 'yii\grid\SerialColumn'],

        ...

        ['attribute' => 'circulo',
         'value' => function($model){
            $items = [];
            foreach($model->circulos as $circulo){
                $items[] = $circulo->cirica_nombre;
            }
            return implode(', ', $items);
         }],

        ...

        ['class' => 'yii\grid\ActionColumn'],
    ],
]); ?>

This gives the expected results. You can then apply filter by the relation fields easily by adapting the search model.