CODEWITHSUNDEEP
asp.netvalidationserverside-javascript
CiccioMiami
CiccioMiami

Reputation: 8256

How to apply Client-side validation by calling a server-side function in ASP.NET

I have an ASP.NET Web Forms application.

I have a Form with various TextBoxand right now I have several asp:RequiredFieldValidator linked to them belonging to the same ValidationGroup.

Now I have to apply to some TextBox an additional validation with related error message. In the specific I got to check whether the text inside the TextBox is a Guid or not. Morevoer this check has to be done on the fly, meaning that as soon as the user moves the cursor from the TextBox the validation has to be performed, without the need to press submit.

  1. How can I call the IsGuid(string guid) function from Javascript?

  2. How can I attach two different error messages as validation (for instance I want to be displayed a message if TextBox.Text has carachters not allowed and lenght < N)

  3. Is it easier to implement this validation with jQuery or with the ASP.NET validators?

If somebody else has any other idea for its implementation, please feel free to propose. Thanks!

Upvotes: 0

Views: 1685

Answers (2)

aleafonso
aleafonso

Reputation: 2256

You can apply as many Validators as you need to the same control, in this case your TextBox.

In this scenario, a Custom Validator is the way to go because it enables you to do the validation with any function you develop to cover your needs. Please, have a look at this simple tutorial.

UPDATE 1: Server Side Validation

This is how it calls the server side function in the declaration of the CustomValidator:

<asp:CustomValidator runat="server" id="custPrimeCheck"
    ControlToValidate="txtPrimeNumber"
    OnServerValidate="PrimeNumberCheck"
    ErrorMessage="Invalid Prime Number" />

Example of the "PrimeNumberCheck" VB function:

Sub PrimeNumberCheck(sender as Object, args as ServerValidateEventArgs)
Dim iPrime as Integer = Cint(args.Value), iLoop as Integer, _
    iSqrt as Integer = CInt(Math.Sqrt(iPrime))

For iLoop = 2 to iSqrt
  If iPrime mod iLoop = 0 then
    args.IsValid = False
    Exit Sub
  End If
Next

args.IsValid = True
End Sub

UPDATE 2: Client Side Validation

This is how it calls the server side function in the declaration of the CustomValidator:

<asp:CustomValidator runat="server" id="custPrimeCheck"
    ControlToValidate="txtPrimeNumber"
    ClientValidationFunction="CheckPrime"
    ErrorMessage="Invalid Prime Number" />

Example of the "CheckPrime" JavaScript function:

function CheckPrime(sender, args)
{
    var iPrime = parseInt(args.Value);
    var iSqrt = parseInt(Math.sqrt(iPrime));

    for (var iLoop=2; iLoop<=iSqrt; iLoop++)
      if (iPrime % iLoop == 0) 
      {
          args.IsValid = false;
         return;
      }

    args.IsValid = true;
}

Thanks to @AdrianIftode for making me aware of this.

Upvotes: 0

Adrian Iftode
Adrian Iftode

Reputation: 15663

You can use ReqularExpressionValidator control.

Here a regex

^(\{){0,1}[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}(\}){0,1}$

Upvotes: 1

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