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javascripthtmlwebformstelerik

JavaScript error: Uncaught TypeError: a[b] is not a function

In my C# Webforms project I have a RadDatePicker control set to run a JavaScript function. Each time I select a date, I get this Javascript error:

Uncaught TypeError: a[b] is not a function

Here is my code. The JavaScript is at the top of the ASPX page that has the control

function SetDateSession() {
    console.log('here');
}


<telerik:RadDatePicker ID="StartDatePicker" runat="server">
    <ClientEvents OnDateSelected="SetDateSession()" />
</telerik:RadDatePicker>

I'm getting the error after selecting a date, and the error occurs before the console log.

I can't figure out why this very simple code doesn't work. If I try to call the function with onclick from an input tag, it works.

<input type="button" id="RepBtn" onclick="SetDateSession()" value="View" runat="server"/>

I've simplified the code so much that it's hard for me to know what to try next.

Answer Summary:

Unlike HTML and ASP.NET, if you're using Telerik's OnClientClicked and passing a JavaScript function, you should not provide the parenthesis. Providing parenthesis will cause the function to fire on page load and NOT on click.

For example, a RadButton generates this HTML:

<a id="exampleBtn" class="RadButton RadButton_Office2010Silver rbSkinnedButton"
  href="javascript:void(0)">
    <input class="rbDecorated" type="submit" name="btnStandard_input" 
      id="btnStandard_input" value="Standard Button" />
    <input id="btnStandard_ClientState" name="btnStandard_ClientState"
      type="hidden" />
</a>

It's an input with a type submit and when you refresh the page, it'll resubmit the form, running your JavaScript function.

Solution

  • What a waste of time on such a stupid thing! Basically this

    <ClientEvents OnDateSelected="SetDateSession()" />

    should be this

    <ClientEvents OnDateSelected="SetDateSession" />

    Lesson learned, Telerik! Thank you.