Onion Structure of OAF

In Simple Terms Onion Structure of OAF means Each layer only “knows” about the layers below it.

This encapsulation promotes easier reuse of components. It helps in Client/Server Code Separation.

From the Above Figure we can see that OA Controller  knows only about Application Module it will now know any thing about what methods from VO, AM is using or from DB it is using . Similar to all the other layers also.

Core Components of Onion Structure are

• Database
• Entity Object
• View Object
• Application Module
• OAController

In Next posts we will read more about each and every component in details and how to use and create usign JDeveloper.

General Guidelines for Reuse Components(Optional - But Best Practices)

• Model Should Never refer any code from View that is from Controller directly.
• Never implement any server side class/interfaces in client side
• If any core complex logic need to executed and make Page light pass the control to server side code via AM only. This is improve the page performance.
• Never include only JDBC or Server side logic in CO directly .