If you have a form, you sometimes need special validation Rules not included in Yii. Here i share a special rule with you, i just wrote. Maybe you have the case, when a user needs to Fill ou Field A oder the Fields B, C and D.
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.