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.
Many applications wish to obtain parts of the URL for the current page (the hostname, the query string, etc.), and the CHttpRequest class wraps various $_SERVER variables to break down the URL into its constituent parts.
If you are coming over from Yii 1.x to Yii 2, and already read this guide, you may note that namespaces are very important in Yii 2 to identify classes. But do you know the list of seeded path aliases that come shipped with a basic or advanced app? Here is my attempt to list them.
I recently had to have a checkbox column in my grid view that supported the 'disabled' attribute. This was easy enough to do by extending the CCheckBoxColumn. However, I also wanted the checkbox to be selected when clicking on the table's row (supported via CGridView's selectableRows option). I discovered I had to tweak yiigridview.js so that it would not select disabled rows when clicking on it or on the 'select all' checkbox.
Backoffice Grid Views often list information like Posts for a blog while showing at the same time linked information like the User who wrote that post.
For more efficiency, it is appropriate that the User is displayed as a link to the User detail page.