Data validation for datetime parameter in SSRS

Hi,

I wanted to know more about validation of SSRS parameters. I have a simple report which has a parameter called startdate of DateTime datatype. The datetime parameter in SSRS takes manual input as well. So, the user can enter any junk value. I want to ensure that the input parameter is in correct format and I want to display an error msg when the format is incorrect. My report has the following VB code for validation:

Public Function Validate( ByVal startdate As String) As Boolean
If IsDate(startdate) = True Then
Return True
Else
Return False
End If
End Function

And my report has a textbox which has the expression property set to;

=Code.Validate(Parameters!startdate.Value)

the textbox on the report has to display if the entered date is valid or not.

But, when i enter an erroneous date, SSRS doesn't render the report and throws a generic error. This happens even before the code written for validating the parameter executes.

Also couldn't find a way to disable the manual input for the datetime parameter. Even that would solve the problem.

Another alternative was to make the startdate parameter as string, but i want the calendar control button to be provided for the user.

The function below checks for the Start and End date ranges .

Function:

Function CheckDateParameters(StartDate as Date, EndDate as Date) as Integer
Dim msg as String
msg = ""
If (StartDate > EndDate) Then
msg="Start Date should not be later than End Date"
End If
If msg <> "" Then
MsgBox(msg, 16, "Report Validation")
Err.Raise(6,Report) 'Raise an overflow
End If
End Function

Steps:

1.) Go the Report Parameters and add a parameter with the datatype is string.

2.) Check the Hidden checkbox and Allow blank value ckeckbox.

3.) From Default Values choose Non-Queried radio button and then press the FX button and paste this code.

=CODE.CheckDateParameters(<parameterStartdate>.Value,<parameterEnddate>.Value)

Then press OK.

Hope this helps......|||

In the sample that you provided, if we enter an improper date as 02/31/2003 [mm/dd/yyyy], then the report execution fails and an error is thrown right away "error occured during the processing of report parameter". I was talking of handling such errors.

I feel that reporting services, initially validates the entered value matches the datatype of the parameter and then proceeds with execution of any VB code and finally renders the report.

When I said validation, I wanted a functionality similar to the client side validation in an asp page, where improper date formats like 12/31/235668 etc can be taken care of.