Application Structure: Application Structure Overview (2024)

Yii applications are organized according to the model-view-controller (MVC)architectural pattern. Models represent data, business logic and rules; viewsare output representation of models; and controllers take input and convertit to commands for models and views.

Besides MVC, Yii applications also have the following entities:

• entry scripts: they are PHP scripts that are directly accessible by end users.They are responsible for starting a request handling cycle.
• applications: they are globally accessible objects that manage application componentsand coordinate them to fulfill requests.
• application components: they are objects registered with applications andprovide various services for fulfilling requests.
• modules: they are self-contained packages that contain complete MVC by themselves.An application can be organized in terms of multiple modules.
• filters: they represent code that need to be invoked before and after the actualhandling of each request by controllers.
• widgets: they are objects that can be embedded in views. Theymay contain controller logic and can be reused in different views.

The following diagram shows the static structure of an application: