In Yii 1.x, there was a built in widget CStarRating based on the jquery star rating plugin. There exists no prebuilt solution in Yii2, however the same concepts can be extended using any jquery plugin.
This article shows a quick and easy way to implement flat user access control system. Flat means, that user access is controlled by level only, which is solution exactly opposite to complex RBAC access systems.
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".