If you're working a lot with extensions you often stumble upon problems, when you want to include them into your custom web application, like hardcoded or absolute path aliases or classes extended from core application components, which implement addiditonal features.
Generally we need to show one or more fields from a model that is related to another model used in CGridView.
For our case we will use two related models, which explain how to use model "A" fields in a CGridView that used model "B".
I have read http://www.yiiframework.com/wiki/24/creating-a-dependent-dropdown/ (Dependen Dropdown Yii1), but I cant implementation in Yii2 because Yii2 not built-in AJAX functionality hem.. I am search about it and get this statement
You have that, when a product is on development they can change its API anytime. This change is quite important though, its related on how to set the events of your form, for example, the useful beforeSubmit.