In oracle BPM, we can put basic screen level validations on the forms, but what if we need to call an enterprise system and depending upon its output, shows some error message to the user on the screen itself.
For example, user enters some value in a form, this value is to be validated from a DB or some third party system. Now what user wants is when he presses OK on ADF form, rather than task moving to next step, he is intimated of the error while he stays on the same page.
I guess, one way to achieve this adding a validation listener to form button and then calling the webservice for this, but this will need coding, a not so user friendly option.
Other way may be using page flows but it also is bit on the techy side.
would really appreciate if anyone can put some lights on it.
You will need to write a managed Bean which extends InvokeActionBean and have your own ActionListener for the button which first does the validation and on success , internally calls invokeOperation().