I want to open data grid and filter the data according to week days through 7 tabs (where every tab has a data grid of the same object) and filtering should be through xpath constraint where i cant use any operations like addDays([%BeginOfCurrentWeek%], 1) to get the corresponding date and filter up on it. I know that I can do that through enumeration but is there any way to use operations on date in this case.
There is no way in XPath constraints to extract weekdays from DateTime attributes. In OQL, it is possible with the DATEPART function, but this function is not available in XPath and OQL can only be used for reports and within Java actions.
I think the best way to do this is the way you wrote and to set the enumeration attribute in a Before Commit event.