Dependant dropdown fields

Hi i’m new to yii

I have a question about fields.

Can i have two dropdown fields but one of them is dependent on the other ?

This is the part of my form :

<?= $form->field($model, 'country_id')->dropdownList(country::find()->select(['name'])->indexBy('country_id')->column()

,['prompt'=>'Pick a country']


<?= $form->field($model, 'city_id')->dropdownList(city::find()->select(['city_name'])->where(['country_id' => $model->country_id])->indexBy('city_id')->column()

,['prompt'=>'Pick a city']


the tables are like so :

country (country_id , ‘name’)

city (city_id , city_name , country_id)

But $model->country_id return NULL.Anyone have an idea how i should procede ?

I think for this you need some javascript code. You can watch about this here

If you’re looking for something ‘ready to go’ check this extension:

Thanks guys.