Question

In my app I have, for example, 3 logical blocks, created by user in such order:

FirstBlock -> SecondBlock -> ThirdBlock

This is no class-inheritance between them (each of them doesn’t extends any other), but logical-inheritance exists (for example Image contains Area contains Message). Sorry, I’m not strong in terms – hope you’ll understand me.

Each of blocks sends requests to server (to create infromation about it on server side) and then handles responses independently (but using same implementation of http client). Just like at that image (red lines are responses, black – requests).

http://s2.ipicture.ru/uploads/20120121/z56Sr62E.png

Question
Is it good model? Or it’s better to create a some controller-class, that will send requests by it’s own, and then handle responses end redirect results to my blocks? Or should implementation of http client be controller itself?

P.S. If I forgot to provide some information – please, tell me. Also if there a errors in my English – please, edit question.

Answer 1

Here’s why I would go with a separate controller class to handle the HTTP requests and responses:

• Reduce code duplication (do you really need three separate HTTP implementations?)
• If/when the communication protocol between your app and server changes, you have to rewrite all your classes. Say for example you add another field to your response payload and your app isn’t built to handle it, you now have to rewrite FirstBlock, SecondBlock, and ThirdBlock. Not ideal.

Modify your Implementation of HTTP client controller class such that:

• All HTTP requests/responses go through it
• It is responsible for routing the responses to the appropriate class.

Advantages?

• If/when you change the communication protocol, all the relevant code is in this controller class and you don’t have to touch FirstBlock, SecondBlock, or ThirdBlock
• Debugging your HTTP requests!