In many cases developers of one project use their own local environments for coding. There may be a common test platform and, of course, production. All these environments usually have different DB credentials and directory structures (first of all, path to YII framework directory). Another feature is debugging. It's convenient to turn it on for local environments, eventually - on the test server and never (generally speaking) - on the production.
After you have setup your Yii2 advanced application, you now have setup your user authentication for both frontend and backend. However, if you have first logged into frontend, and try to access backend from the same client machine, you see no login screen, but find yourself automatically logged in.
I needed to use a class from ZF2 in my Yii project.
I've read probably all there is about this subject and still I needed lots of trial & errors to get it working, probably due to my lack of experience working with namepsaces and ZF2 in general. Also, the resources on the web are all partial, at best. Most simply refer to ZF1 where things are technically different. When I got it all working I decided to record my findings and that's how this article was born. The below recipe is what worked for me, accompanied by relevant comments.
References: This article is partially based on this guide page. Be sure also to consult Zend Framework 2 documentation.
If you are coming over to Yii 2 from Yii 1.x, you may have already read this useful wiki for creating dependent dropdowns.
You can use a similar approach in Yii 2 to do the same. But if you are looking at a prebuilt solution that helps you manage it easier, read along.