Description Christian Damus 2019-06-28 10:19:11 EDT

The ValidationService (the view-model service, not the ad hoc service) provides a listener protocol that reports, after a validation occurred, the current "validation result".  This validation result is the set of Diagnostics attached to the root of the view model (the top VView).

That is fine for applications that don't throttle the presentation of validation problems.  For applications that do, the root view model element will not have all of the diagnostics.  It will only have up to the defined limit and, if necessary, one more problem that's a placeholder indicating to the user that there are other unreported problems.

For applications that present validation problems in some other visualization besides decorations within the editor (for example, a dedicate view part), there is no easy way to get the set of all validation problems:  listening to the validation service cannot provide all of the problems and nor can scraping the VDiagnostics attached to the view model.  During the processing of the validation queue, the ValidationService does have a complete picture of the validation state of all of the objects that it validated.  This is the case both for the initial full validation of the model and any incremental validation updates.  A new incremental update listener protocol would be of value to help applications maintain a complete view of the validation state of the model.