TAB_FILES_EDIT widget: Validating files
For one of my types I need to validate uploaded files compliance against a web service. This works pretty well with the main content action widget, and now I want to trigger my validation code from the TAB_FILES_EDIT widget.
I was planning to use the fileUploadListener attribute for it but It does not seem to works. While I get exception thrown based on the validation response as expected It leads to strange UI behaviours and unwelcome seam transaction errors in the logs.
I don't get how the widget works. Is there any resource or source code to help me with this ? How does the files ends up being stored in VCS ?
Sorry if I missed it but search engines didn't show a great help on this topic.