How to enforce Validation

[kebele]

I have a search page with one text box and two dropdowns for the users to make a selection.I would like to enforce the users to make at least one selection from the dropdowns or enter a value to the textbox before doing any searching.Do I have to write javascript for this or is this someting that can be done using validation controls? any help would be appreciated.

 

[TipGiver]

You can do it with 2 ways:
1. client side (javascript)
2. server side (validation controls) <-- prefer

For your case, i would use a CUSTOM validator.

 

[kebele]

So all i need to do is just write my own function and apply that to the three controls i have? If my thought is wrong , can you give me an example how this can be done.
thanks

 

[BoulderBum]

Using the custom validator, you can have both server- and client- side validation code via OnServerValidate and ClientValidationFunction respectively, thus you get the performance benefits of the javascript methodology plus the security of the server-side code.

In the .aspx:

<asp:CustomValidator runat="server" id="cstSelectionCheck"
        OnServerValidate="Server_CheckSelections"
        ClientValidationFunction="CheckSelections"
        ErrorMessage="You must make a selection." />

In the code-beside:

protected void Server_CheckSelections(object sender, ServerValidateEventArgs args)
{
    bool selectionMade = false;
   
    //write code to see if selection is made, set to true if so

    args.IsValid = selectionMade;
}

//*******Upon Clicking a Button or Whatever*********
if( Page.IsValid )
{
     //perform the logic for a valid page
}

On the client:

<script language="JavaScript">
<!--
  function CheckSelections(sender, args)
  {
    var selectionMade = false;
   
    //write code to see if selection is made, set to true if so

    args.IsValid = selectionMade;
  }
// -->
</script>

This may also help:

http://www.codeproject.com/aspnet/MultiDependValidator.asp

 

[kebele]

thank you guys I have gone this far and It is not working for me.It just does not show error msg even if i do not make any selection. any Idea?

<asp:CustomValidator ID="AtLeastOneSelection" runat="server"
ErrorMessage="You must make a selection."
ValidateEmptyText="true" OnServerValidate="AtLeastOneSelection_ServerValidate"
Width="624px">
</asp:CustomValidator></span></div>

mycode behing:

Protected Sub AtLeastOneSelection_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles AtLeastOneSelection.ServerValidate

If (txtVendorName.Text <> "") And (drPur.SelectedIndex <> 0 And drPurM.SelectedIndex <> 0) Then
args.IsValid = True
Else
args.IsValid = False
End If
End Sub

 

[BoulderBum]

Are you checking Page.IsValid before executing whatever logic you want to execute if a selection is made?

 

[kebele]

yes I did that. I am looking at the link you provided to me and it seems that i have to create a user control for my code to work right.right? can i do this without creating a user control? thanks

 

[kebele]

It works fine when i only validate one control like this
Protected Sub AtLeastOneSelection_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles AtLeastOneSelection.ServerValidate

If (drPur.SelectedIndex <> 0 And drPurM.SelectedIndex <> 0) Then
args.IsValid = True
Else
args.IsValid = False
End If


End Sub


but when i want to validat more than one control then It does not work

This one does not work:
Protected Sub AtLeastOneSelection_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles AtLeastOneSelection.ServerValidate

If (drPur.SelectedIndex <> 0 And drPurM.SelectedIndex <> 0) And (txtVendorName.Text <> "") Then
args.IsValid = True
Else
args.IsValid = False
End If


End Sub

any help would be appreciated.

 

[kebele]

I figured out what my problem was.I was using "AND" instead of "or".Once I changed that it worked for me. thanks you all for your tips and help.