If you want to edit data directly in the gridview in a 'dropdownlist' style, then you could use the 'type' => 'select' option of TbEditableColumn (YiiBooster) or EditableColumn (x-editable for Yii). This wiki shows how to get data from the db for the 'dropdownlist', by converting AR model data into an array that is passed in json format.
Through the YouTube API you can upload files directly to the Youtube server. Youtube currently offers two services 1. Direct Link 2. Browser Based Uploading. In this wiki I will demonstrate how you can quickly set Browser Based Uploading for your Yii application. This is the protocol request that takes place.
There are some good guides out there explaining how to work with events and the ways to attach them to your components, but none (that I know) explain the following way to configure your events with CAction classes on your controllers the following way.