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.
Many Yii users ask how to create helper classes and functions, and though there are numerous approaches spread out among the forum and wiki articles, this Tutorial tries to bring it all together in one place.
I needed British (dd/mm/yyyy) formatted dates throughout my application but found it very difficult to find examples of how to do this - until I found this excellent forum post http://www.yiiframework.com/forum/index.php?/topic/3649-dealing-with-i18n-date-formats/
I have read http://www.yiiframework.com/wiki/24/creating-a-dependent-dropdown/ (Dependen Dropdown Yii1), but I can't implement it in Yii2 because Yii2 does not have built-in AJAX functionality hem.. I searched about it and came across this post
Using CActiveRecord->updateAll() and CActiveRecord->deleteAll() with scopes and criteria requires some tricks that are explained in this article. While findAll() , find() and some other methods use scopes automatically, updateAll() and deleteAll() do not.