Before rendering of page results in to some output , You might want to run pre-requisite procedure or methods for performing business or criteria logic.
If you want to achieve this at User Interface level then mostly developers use “InvokeAction” provided by ADF framework.
Then I added this method as InvokeAction which will be called before iterator in Executables box which will make sure it is called before the iterator renders OracleItem list on table component on User Interface.
Finally when you run the page it will only show rows with order id 1004. This was just for test purpose , you can use it for various reasonable business criteria.
If you have noticed I kept Refresh to IfNeeded that means it will call this method by default. You can also put some Refresh Condition that will prevent this criteria to be executed or allow the criteria to be executed based on some condition.