With Yii Framework 2.0, one of the many changes, that Yii 1.x developers will face is removal of all client helpers and revamp of the CClientScript functionality. For example no more CHtml::ajaxLink or Html::ajaxLink. How do you cater to such requirements in Yii 2.0?
With Bootstrap 3 and its inbuilt support in Yii Framework 2.0, you would see quite some new ways of creating HTML markup and styling your site. However, with version 3 of Bootstrap, tooltips and popover are not activated by default on your elements. Assuming you have activated the Bootstrap 3 tooltip plugin - how do you easily enable display of tooltips/popovers across your site?
Ok, so you have a HTML 5 file input markup on your view and you have enabled multiple attribute to true. You may also be using widgets based on HTML5 input like \kartik\widgets\FileInput. But when you read a file in Yii controller using CUploadedFile (Yii1) or UploadedFile (Yii2), you do not see a list of multiple files that you selected in your view, but only one row. Your HTML markup in your view would be something like this and you don't know why this is not working?
With the adoption of PJax on Yii2 things have change quite a bit with GridView when it comes to work with them in AJAX mode. It will probably be confusing at the beginning, but then you will soon realize how powerful the new approach is.