Hello,

Thank you for your question regarding WebGrid.

I made a work around that you might try. I add validation code in OnBeforeRequest client side event.
The code validate whether the input is a valid date format or not.
The code will continue the filtering process if the date format is valid.

function DoBeforeRequest(gridId, action) {	var grid = ISGetObject(gridId);
	if (action == "ColumnFilter") {
		var selObj = grid.GetSelectedObject();
		var rowObj = selObj.ToRowObject();
		var cellRequiredDate = rowObj.GetCells()[5];
		var dateValue = cellRequiredDate.Value.toString();
		if (dateValue == "Invalid Date") {
			alert("Please insert valid date");
			return false;
		}
		else {
			alert("Thank you");
			return true;
		}
	}
}

I implement the validation code in one of WebGrid Sample Solution, PreserveCheckedRows.aspx page.
Please kindly have review on the attached sample to see the result.

If you can’t get the sample properly, please try to follow this link: http://1drv.ms/1hPGyuQ

I apologize for any inconvenience this problem may have caused you.

Regards,
Hans K.

Thank you for your reply. I have modified the workaround to meet my needs and it is acceptable for now (I changed it to loop through the cells and check for System.DateTime column types and "Invalid Date" values).

Are there any plans to change the code so that it's more consistent with other filter types? For example, to return 0 results when an invalid value is entered rather than throwing an exception? Without it, we need to add a workaround similar to this for each grid that has a System.DateTime filter.

Hello,

I am sorry; currently there isn’t any plan to add this work around as a WebGrid feature.
I will forward this scenario to the developer team.
I will let you know if there is an update regarding this scenario.

Thank you and I apologize for the inconvenience.

Regards,
Hans K.