codeigniter PHP中的MVC设计

Question

When should a new model or controller be made? Should there only be controllers that go with a corresponding view 1 to 1 and like so with controllers and models? Or is it good practice to have controllers for functionality not tied up with any particular view? Take for example voting, should all voting code go in a voting controller or be spread among controllers that have views using voting. Seems likely a voting controller would be best.

Answer 1

First of all , you cannot actually implement classical MVC in php. The best you can do is Model2 MVC.

• Model - responsible for all the business logic. Has no clue about where the data is stored or actually comes from. The storage and retrieval is responsibility of DataMappers or DAOs. Model itself should never contain SQL. Ever.
• Controller - binds model(s) to the view and changes the state of both. It does not retrieve information from models for sending it to view.
• View - responsible for all presentational logic. Retrieves information from models and binds it to appropriate templates. View itself is not a template.

You can wither have 1:1 relationship between views an controller or many:many. it depends on how you implement the view itself.

For example, your view can require a separate object which handles the rendering. And providing different type of objects ( this is where polymorphism matters ), you can make your view to render either xml, html or json.

Or you can do the same by changing the templates. A ListView class can render a list of articles as well as list of users, if the basic presentation logic does not change and you provide just a different template for each.

In the case of voting , it seems ok to have a single controller for all voting related operations, and you can have a single view with switching the templates for your output.