Dynamically generated CompareValidator not working right.

[dolot]

I'm new to this asp.net stuff. My dev lead and I are both trying to learn how to do this. He built some pages and asked me to add the validation controls to them.

The first page has a series of text boxes with autopostback = true. I can put CompareValidators onto the form and assign them to the textboxes, and they seem to work right.

On my second page, however, the controls are being built on the server using vb code. The CompareValidators seem to work on the client side. On the server side, however, the CompareValidators always have an IsValid property = true, even when the value of the textbox clearly violates the conditions. I've checked all the properties I can think of and I can't see any difference between these dynamically generated validators and the static ones I have on the first page, so I'm thinking there must be something else going on.

Let me know if you need any more info or have any ideas.

[dolot]

Well, I never figured out why they are showing valid on the server side, but I did discover that when I set textbox.causesValidation = true, the client side validation occurs and the value never even goes to the server. So basically my problem is solved - no more invalid values getting to the server.

I feel like such a noob.

[gep13]

Hello,

Is it possible to show the code that you are using? It sounds like the controls that you are creating don't have their event handlers hooked up at the right point, therefore when the events fire, they are not being called.

The reason that I ask is that the problem isn't really solved. You can't rely on JavaScript being enabled on the page, or that some malicious user won't manually switch off JavaScript. As a result, you should definitely still validate the input on the server side. Client side validation should be seen as a convenience for the user preventing the need for round trips to the server, not as the only validation.

Thanks

Gary

[dolot]

OK. Here's the snippet of code that creates the panel, textbox, and validator:

                    'add a spot to hold the value
                    Dim ValueCell As New Web.UI.HtmlControls.HtmlTableCell
                    Dim Panel As New UpdatePanel
                    Panel.UpdateMode = UpdatePanelUpdateMode.Conditional
                    Panel.ID = "panel_" & Variable.Name
                    ValueCell.Controls.Add(Panel)
                    NewRow.Cells.Add(ValueCell)

                    'add the editor for this item
                    Dim EditorControl As Control = Editor.CreateVariableEditor(Variable, HostTable.Page, VariableManager)
                    Panel.ContentTemplateContainer.Controls.Add(EditorControl)

                    'add the validation control - if any.
                    Dim ValidationControl As CompareValidator
                    ValidationControl = Editor.CreateVariableValidator(Variable, HostTable.Page, VariableManager)
                    If ValidationControl IsNot Nothing Then
                        ValidationControl.ControlToValidate = EditorControl.ID
                        Panel.ContentTemplateContainer.Controls.Add(ValidationControl)
                    End If

Here's the snippet from CreateVariableEditor that creates the textbox:

                    Dim TextBox As New TextBox
                    TextBox.AutoPostBack = True
                    TextBox.CausesValidation = True
                    TextBox.ID = "VAR_" & Variable.Name
                    TextBox.Text = Page.Session.Item(Variable.Name)
                    AddHandler TextBox.TextChanged, AddressOf Editor.VariableTextBox_TextChanged
                    CreateVariableEditor = TextBox

and here's the snippet from CreateVariableValidator that creates the CompareValidator:

                Dim ValBox As New CompareValidator()
                With ValBox
                    .ValueToCompare = 10
                    .Type = ValidationDataType.Integer
                    .Operator = ValidationCompareOperator.GreaterThan
                    .ErrorMessage = "Value must be greater than " & .ValueToCompare.ToString
                    .ID = Variable.Name.ToUpper & "_VALIDATOR"
                    .SetFocusOnError = True
                End With

Finally, the event handler and a related function:

    Public Shared Sub VariableTextBox_TextChanged(sender As Object, e As System.EventArgs)

        With CType(sender, TextBox)

            'get the variable name
            Dim VarName As String = .ID.Substring(4)

            'fish out any validator and check it
            Dim Validator As CompareValidator = GetValidator(CType(sender, TextBox), VarName)

            'apply the variable value
            Using VariableMgr As New SessionVariables(.Page.Session)
                If Validator IsNot Nothing Then
                    If Validator.IsValid Then
                        VariableMgr.SetSessionVariable(VarName, .Text)
                    End If
                Else
                    VariableMgr.SetSessionVariable(VarName, .Text)
                End If

            End Using

        End With

    End Sub

    Private Shared Function GetValidator(ByVal C As Control, Name As String) As Control

        For Each ValC As Control In C.Parent.Controls
            If ValC.ID.Contains(Name & "_VALIDATOR") Then
                Return ValC
            End If
        Next

    End Function

[gep13]

Hey,

Which page level events are you doing this work in though?

Is it possible to upload the entire aspx and aspx.vb files?

If not, can you put it together in a small sample application and upload that?

Ultimately, I suspect the issue is going to be with when the control are created within the ASP.Net Page Life Cycle, as described here:

http://www.4guysfromrolla.com/articles/092904-1.aspx

Gary

[dolot]

It's happening through the page_load event. I'll try to upload the page and support class tomorrow.

[gep13]

It's happening through the page_load event. I'll try to upload the page and support class tomorrow.

Ok, so as per the article that I linked to, that is not early enough in the ASP.Net Page Life Cycle. You will have to alter your code as per the article.

Gary

[dolot]

Thanks, Gary. I'll go ahead and read that article and the companion articles with it and go from there. If I'm still having issues I'll post again.