Hi,

I am writing a web application using Expression WEB and VWD2005.

Because I start creating a web page with Expression Web, my pages don't have separate behind code pages. All the scripting is done in the .aspx page.

I used few custom validation controls to determine if a certain value is already given to a field in a record already stored (say a customer sequence number, that is not the record key!).

When debugging  the application with VWD2005 I noticed that the program passes twice trough the custom validation subroutines, which creates a problem to the application.

In fact, when inserting new records, because I am checking if some value is already used, in the first pass (let's say that the value is not already used), the new record is inserted, but in a second pass, checking for the same value, it finds the newly added record, giving that way an error message stated in the custom validation control!

I double checked this way of the program running twice trough the routines and even created a new very simple page with only a formviev and a custom validation control to be used during the insert process of a new record, but it actually runs that way. Is this normal or am I missing some point in the validation process?

To give more details, I use to clear the command name property of the link buttons in the formView (the insert, update and delete buttons created automatically by the formview control) and instead use the OnClick event of the buttons to have more precise control over the insert, update or delete operations, using a try... catch structure. 

Here is test example of some code for the update process. The code first executes the custom validation subroutines, than the update sub and then again the custom validation subroutines!

 thanks for helping

1    <script runat=server>
2        
3        Protected Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)
4                
5            If args.Value > #12/31/2008# Then
6                args.IsValid = False
7            End If
8    
9        End Sub
10      
11       Protected Sub CustomValidator2_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)
12               
13           If args.Value > 1000 Then
14               args.IsValid = False
15   
16           End If
17       End Sub
18   
19       Protected Sub UpdateButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
20           If Page.IsValid Then
21               Try
22   
23                   FormView1.UpdateItem(True)
24                   Label1.Text = "Correzione inserita!"
25               Catch ex As Exception
26   
27               End Try
28           End If
29   
30       End Sub
31   
32   </script>
33   

 Problem solved .......but still don't understand why writing code the way I posted initially (that seems to me the simplest way!) the validation code must run one time before the onClick event handler and another time after the onClick event handler.

Anyway, after dozens tries, I eventually came up to the following solution.

First, I set the "CausesValidations" property to "False" to the button that postsback the page  (the UpdateButton in this case). This avoids running the validating codes as soon as the page loads.

So the first code running is the UpdateButton_Click. Within this event handler I inserted a Page.Validate() call, that in turn calls the validation subroutines. Once the validation routines executed, the UpdateButton_Click event handler resumes testing the Page.isvalid property, deciding to execute or not the update command. At the end of the sub, program resumes showing the page with the result of the validation  process (validation summary messages) or the result of the command (Update in this case), so avoiding running once again the validation code for mysterious (to me!) reasons.
 The sample code below is different from the one posted initially, but nothing changes  related to the problem encountered.

1        Protected Sub UpdateButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
2            Page.Validate()
3            If Page.IsValid Then
4    
5                Try
6                    FormView1.UpdateItem(True)
7                Catch ex As Exception
8    
9                End Try
10           End If
11   
12       End Sub
13   
14       Protected Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)
15           If args.Value = "President" Then
16               args.IsValid = False
17           End If
18       End Sub
19   
20       Protected Sub CustomValidator2_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)
21           If args.Value = "Ufficio" Then
22               args.IsValid = False
23           End If
24       End Sub