RadListBox: CheckBoxes=true and RequiredFieldValidator

[Morten]

I have a radlistbox:
<telerik:RadListBox ID="rlb" runat="server" CheckBoxes="true" />

and a reguiredfieldvalidator:
<asp:RequiredFieldValidator runat="server" ID="rfv" ControlToValidate="rlb">*</asp:RequiredFieldValidator>

The Required field validation works fine when at least one item is selected (highlighted).

How can I get the RequiredFieldValidator to accept a checkbox.checked item (not highlighted) as a valid pass?

[Shinu]

Hi Morten,

One option is by using CustomValidator control for validating the RadListBox as shown below. Give a try with following client side code.

ASPX:

<telerik:RadListBox runat="server" ID="RadListBox1" CheckBoxes="true" Height="200px" Width="230px">
</telerik:RadListBox>

<asp:CustomValidator ID="CustomValidator1" runat="server" ClientValidationFunction="ValidationCriteria" ErrorMessage="CustomValidator">
</asp:CustomValidator>

JavaScript:

<script type="text/javascript">
function ValidationCriteria(source, args)
{
    var listbox = $find('<%= RadListBox1.ClientID %>');
    var check = 0;
    var items = listbox.get_items();
    for(var i = 0; i<= items.get_count()-1; i++)
    {
        var item = items.getItem(i);
        if(item.get_checked())
        {
            check = 1;
        }
    }
    if(check)
        args.IsValid =true;
    else
        args.IsValid = false;
}
</script>

-Shinu.

[Veselin Vasilev]

Hello guys,

The javascript method could be even more optimized:

<script type="text/javascript">
function ValidationCriteria(source, args)
{
    var listbox = $find('<%= RadListBox1.ClientID %>');
    args.IsValid = listbox.get_checkedItems().length > 0;
}
</script>

All the best,
Veselin Vasilev
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Check out the tips for optimizing your support resource searches.

[N S]

How do I validate if any checkboxes are checked once the RadListBox is used inside a RadGrid?

I'm having trouble with Validation Script: RadListBox1 is not accessible, since it is part of the EditForm of a RadGrid.

<script type="text/javascript">

function ValidationCriteria(source, args)

{

var listbox = $find('<%= RadListBox1.ClientID %>');  //RadListBox1 is part of the EditForm of a grid, so it cannot be accessed here

args.IsValid = listbox.get_checkedItems().length > 0;

}

</script>

);  

I cannot use the findControl() function of the RadGrid to find the RadListBox1. How do I find the RadListBox1 to validate it? Or is there another way?

[Veselin Vasilev]

Hello,

Please check this help topic on how to easily find a reference to the RadListBox object by using a global javascript variable and the OnClientLoad event.

All the best,
Veselin Vasilev
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[N S]

This works great, thank you.

Kind regards

[Regino Rivera]

Hi N S:

I'm trying to do exactly what you did but I still get errors when trying to validate the RadListBox that is inside the RadGrid ... could you please put all together your code? Thanks a lot

[Bill]

No errors on the page, but it doesn't do anything either...

   <script language="javascript" type="text/javascript">
        function validatelistbox1(source, args) {
            var listbox = $find('<%= rlbEvalReason.ClientID  %>');
            args.IsValid = (listbox.get_checkedItems().length > 0);
        }
        function validatelistbox2(source, args) {
            var listbox = $find('<%= rlbErgoExp.ClientID  %>');
            args.IsValid = (listbox.get_checkedItems().length > 0);
        }

    </script>


                             <td valign="middle">
                                    <a style="font-family: arial" >Evaluation</a><br />
                                    <a style="font-family: arial">Reason:</a>
                                </td>
                                <td>
                                    <asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="rlbEvalReason"
                                        ErrorMessage="You Must Choose At Least 1" ClientValidationFunction="validateListbox1">
                                    </asp:CustomValidator>
                                    <telerik:RadListBox ID="rlbEvalReason" runat="server" DataKeyField="REASON_ID"
                                        DataSortField="REASON_DESC" DataSourceID="sdsEvalReason"
                                        DataTextField="REASON_DESC" DataValueField="REASON_ID" CheckBoxes="true">
                                    </telerik:RadListBox>
                                </td>
                                <td>&nbsp;&nbsp;</td>
                                <td valign="middle">
                                    <a style="font-family: arial" >Ergo</a><br />
                                    <a style="font-family: arial" >Exposure:</a>
                                </td>
                                <td>
                                    <asp:CustomValidator ID="CustomValidator2" runat="server"  ControlToValidate="rlbErgoExp"
                                        ErrorMessage="You Must Choose At Lease 1" ClientValidationFunction="validateListbox2">
                                    </asp:CustomValidator>
                                    <telerik:RadListBox ID="rlbErgoExp" runat="server" DataKeyField="DESCRIPTION"
                                        DataSortField="DESCRIPTION" DataSourceID="sdsErgoExposures"
                                        DataTextField="DESCRIPTION" DataValueField="DESCRIPTION" CheckBoxes="True">
                                    </telerik:RadListBox>

                                </td>

[Veselin Vasilev]

Hi Bill,

I noticed two problems with your code:

1. The name of the javascript function was not the same case, compare
ClientValidationFunction="validateListbox1" with validatelistbox1
The casing should be the same

2. Please remove the ControlToValidate property of the custom validators.

Hope this helps

Greetings,
Veselin Vasilev
the Telerik team

Instantly find answers to your questions on the new Telerik Support Portal.
Watch a video on how to optimize your support resource searches and check out more tips on the blogs.

[Bill]

Thanks,

I really wish MS would decide whether all of their dev. languages are case sensitive or not - or that I could stop having to jump back and forth between them....

[Hendra]

Why do we need to "remove the ControlToValidate property of the custom validators" as specified below?

If we remove it, the listbox will only be validated after the page is post back.

Please advise.

Thank you,

Hendra

[Veselin Vasilev]

Hi Hendra,

The reason is because when you have a RadListBox with ID = "myListBox" actually that ID becomes the ID of the outer DIV that surrounds the listbox items. Setting the ControlToValidate="myListBox" will try to validate the DIV with that ID which is not what you want.

Sincerely yours,
Veskoni
the Telerik team

Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items.

[Jason]

To perform Client Validation on checkbox checking you can manually trigger validation using the OnClientItemChecked event handler

<telerik:RadListBox runat="server" ID="chkListTrainers" CheckBoxes="true" OnClientSelectedIndexChanging="OnClientSelectedIndexChangingHandler" EmptyMessage="There are no trainers to choose from" Height="150px" Width="300px" OnClientItemChecked="OnClientItemChecked" EnableEmbeddedSkins="false" />
<br />
<asp:CustomValidator runat="server" ID="RFVTrainer" CssClass="warning" ClientValidationFunction="ValidateTrainers" ErrorMessage="* At least one trainer required" ValidationGroup="Access"/>

function OnClientSelectedIndexChangingHandler(sender, e) {
    e.get_item().set_checked(!e.get_item().get_checked());
    if (typeof(Page_ClientValidate) == 'function')
    {
        Page_ClientValidate('Access');
    }
    e.set_cancel(true);
}

function ValidateTrainers(source, args)
{
    var listbox = $find('<%= chkListTrainers.ClientID %>');
    args.IsValid = listbox.get_checkedItems().length > 0;
}

function OnClientItemChecked(sender, e)
{
    if (typeof(Page_ClientValidate) == 'function')
    {
        Page_ClientValidate('Access');
    }
}

[mukesh]

hi
this is work afer click on listbox ,butt in my case i want if user click save without selecting list item validation should fire. i tries to call java script on client click of bottun but it doesn't work. please let me known that how it is poassible.
 thanks
 mukesh

[Jason]

Are you using an ASP button or a html button?

If it's an ASP Button then make sure you have set CausesValidation="true".

[mukesh]

i have created  news Regarding our Website...they are lot many..many many..
my  question is...can we add some search control for these news,so that user can search news and can see the description...

or we can made a search control on to this information ...if then please let me know...in which datatable it is being stored.

[mukesh]

Hi, we are creating a newspage  for our website.,  this page is  containing  a huge information.,,,we want  to enable a web user to search those news.,is there any kind of feature provided in sitefinity or not.

[Jason]

Hi Mukesh,

I suggest you start a new discussion, possibly under the "General Discussion" section, for this query.

Cheers,
Lourein

[Thad]

Hi Veskoni ,

If we can not set the ControlToValidate, how do we get the RadListBox to work with validation extenders that use the control to validate element to position a tooltip over the appropriate control that is in error?

Thanks!
Thad

[Dimitar Terziev]

Hi Thad,

I'd like to ask you to open a support ticket with your current problem, since this forum thread has already been filled with off-topic posts.
Thank you and sorry for the inconvenience caused.

Kind regards,
Dimitar Terziev
the Telerik team

[Bill]

In my case. I do not care if items are checked, I simply want to ensure the RadListBox has items in it, that were transferred from another RadListbox to the left of it.


This works:

<telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">
<script language="javascript" type="text/javascript">  
    function validateListBox(sender, args) {
        var listbox = $find('<%= RadListBox2.ClientID %>');
        var check = 0;
        var items = listbox.get_items();
        var cnt = items.get_count();
        if (cnt)
            args.IsValid = true;
        else
            args.IsValid = false;  
    }
</script>
</telerik:RadCodeBlock>

[Tash]

Is it possible to make 2 checkboxes required on a radlistbox unless antoher checkbox is checked that is not part of the radlistbox then only one checking inside the radlistbox is required. If so can you provide an example.