Provide Observable ErrorMessage at entity level & at Collection Level so that error messages can be displayed next to entity and then again
IN LOB application it is very critical to display error message next to the field in error as well as summary of errors.
When Binding the collection to HTML table, expose the Error Collection so that error message can be displayed in data-bind. This should be observable so that it HTML markup is updated dynamically when errors occurs and is cleared when error are corrected.
Similar observable error collection as List level to display summary of error as well. since this is summary, when clicking on error item, ability to set focus to the Editable filed in HTML table would be bonus thing to do
If would be nice to have IsValid and errorMessage(s) observables at the property and entity levels that we could use for binding on forms. That would save having to copy all of the validation rules from Breeze into something like knockout.validation.