Searching in GridView column with relation in Yii2

Question

I have a model with foreign key city_id that references table Cities (id). In the GridView I show city title instead of id, and I know how to add searching for column with foreign key, i.e, in view:

GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [
       //some columns
        [ 
            'attribute' => 'city_id',
            'value'=>'city.title
        ],
]);

And in search model (search() function) I add:

$query->joinWith('city');
$query->andFilterWhere(['like', 'cities.title', $this->city_id]);

And it works fine. But I also want to show region in my grid, and my table Cities has a foreign key region_id which references Regions(id). I added the region title to the grid:

 GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [
       //some columns
        [ 
            'attribute' => 'city_id',
            'value'=>'city.title
        ],
        'city.region.title_en',
]);

Now I dont know how to add searching and how to change search() function, because I dont have region_id in my main model, I retrieve it through city. I would appreciate any advise.

Answer 1

do not forget to add region_id to your search model.