How to use addInfoMessage() (or any UI popup/dialog message) in Flow Designer Action ... WITHOUT using Business Rule or externally triggering Action?

[Wayne C]

We have a Flow that is validating required fields on Tasks created by the Flow. If the validation fails we revert the Task to previous State and wait for the State to change once again to a Closed state and repeat.

When reverting the State, we need of way of telling the user what required field is missing. If the validation were performed in a Business Rule this would just be a simple gs.addInfoMessage(), but we have a requirement to NOT create Business Rules that run on Global tables.

I've tried a custom FD Action with a single gs.addInfoMessage() line, but even though that does not raise an exception the message is never shown.

How do I generate a popup message within FD without a Business Rule ... triggering Action outside of FD with a script is not an option, it's essentially doing same thing as BR.

[Hitoshi Ozawa]

AFAIK, there's no way to set infoMessage from Flow Designer.

Instead of validating required fields on Flow Designer, it would be better to make the field mandatory using UI Policy or Client Script so the user would know missing fields before the form is submitted.

[Wayne C]

That only works if task record is open for editing (in the proper view) in browser, since Client scripts only have access to DOM Elements in browser window. 

That won't work if: task is closed via list view, or task is closed via VTB. The validations need to work in those scenarios as well.

[Hitoshi Ozawa]

That's true.

How about sending notification?