Difference in between Modules and extension in Yii

Question

I want to know what is the difference in between modules and components in Yii Framework. I have googled so much but not got any good results. So can some one will help me out to know that. Any help and suggestions will be highly appreciable.

Answer 1

Module has an MVC structure. A module is a self-contained software unit. Module is a special case of extension. An extension usually serves for a single purpose. In Yii's terms, it can be classified as follows:

1. application component
2. behavior
3. widget
4. controller
5. action
6. filter
7. console command
8. validator: a validator is a component class extending CValidator.
9. helper: a helper is a class with only static methods. It is like global functions using the class name as their namespace.
10. module
11. something else

Answer 2

Extensions may actually be modules but sometimes aren't. A module contains models, views, and controllers while an extension may only be something like a widget.

Answer 3

I guess Yii extension is under protected/extensions directory and for single purpose, it can never be a module. Modules are under protected/modules directory. Those extensions on yii offical website and extensions in yii MVC framework are not the same.