These newsletters have always been hard to create as regular web HTML is not properly read by web email interfaces and email clients. I thought that the simplest solution would be to use a web page that would serve as a web version of the newsletter and turn it somehow into newsletter HTML.
This tutorial is not about allowing users to sign into your application by using any of the OAuth providers available with the official yii2-authclient extension, it is about how to interact with your Twitter account, the one you set for your Yii2 app to promote your site, using the Single Access Token technique.
This article shows a quick and easy way to implement flat user access control system. Flat means, that user access is controlled by level only, which is solution exactly opposite to complex RBAC access systems.
I was playing around with another PHP framework which I didn't really liked anyway but it had simple and nice integration for PHP built in web server so I decided to write one for Yii (since this is my primary PHP framework)