How to check if client script is already registered during a partial postback

Question

Below is the code I've currently implemented.

if (!Page.ClientScript.IsStartupScriptRegistered(Page.GetType(), scriptKey))
{
  ScriptManager scriptManager = ScriptManager.GetCurrent(page);
  if (scriptManager != null && scriptManager.IsInAsyncPostBack)
  {
    //if a MS AJAX request, use the Scriptmanager class
    ScriptManager.RegisterStartupScript(Page, Page.GetType(), scriptKey, script, true);
  }
  else
  {
    //if a standard postback, use the standard ClientScript method
    Page.ClientScript.RegisterStartupScript(Page.GetType(), scriptKey, script, true);
  }
}

I'm doing as suggested in this answer so that I can register startup script on both times i.e. when there is partial postback and a full postback.

The problem is Page.ClientScript.IsStartupScriptRegistered(Page.GetType(), scriptKey) always (even when the script is registered before) returns false when it is partial postback. And I couldn't find ScriptManager.IsStartupScriptRegistered (static) method. As a result of this, additional script is emitted on all partial/async postbacks.

Please note that I'm using script manager of AjaxControlToolkit version 4.1 i.e. ToolkitScriptManager in my masterpage. But I don't thing it has something to do with this.

UPDATE

  <asp:UpdatePanel ID="ContactDetailsUpdatePanel" UpdateMode="Conditional" runat="server">
    <Triggers>
      <asp:AsyncPostBackTrigger ControlID="UpdateContactDetailsButton" EventName="Click" />
    </Triggers>
    <ContentTemplate>
      <div id="ContactDetailsContent" class="contact_details_content">
        <div class="customer_contactdetails_left_pane">
          <div class="customer_name_field">
            <asp:Label ID="CustomerNameLabel" runat="server" Text="Customer" />
            <asp:TextBox ID="CustomerNameValue" runat="server" />
          </div>
          <div class="customer_address_field">
            <asp:Label ID="CustomerAddressLabel" runat="server" Text="Address" />
            <asp:TextBox ID="CustomerAddressValue" runat="server" />
            <asp:TextBox ID="CustomerAddressValue1" runat="server" />
            <asp:TextBox ID="CustomerAddressValue2" runat="server" />
            <asp:TextBox ID="CustomerAddressValue3" runat="server" />
          </div>
          <div class="customer_postcode_field">
            <asp:Label ID="CustomerPostcodeLabel" runat="server" Text="Postcode" />
            <asp:TextBox ID="CustomerPostcodeValue" runat="server" />
          </div>
        </div>
        <div class="customer_contactdetails_right_pane">
          <div>
            <asp:Label ID="CustomerContactLabel" runat="server" Text="Contact" />
            <asp:TextBox ID="CustomerContactValue" runat="server" />
          </div>
          <div>
            <asp:Label ID="CustomerTelephoneLabel" runat="server" Text="Telephone" />
            <asp:TextBox ID="CustomerTelephoneValue" runat="server" />
          </div>
          <div>
            <asp:Label ID="CustomerMobileLabel" runat="server" Text="Mobile" />
            <asp:TextBox ID="CustomerMobileValue" runat="server" />
          </div>
          <div>
            <asp:Label ID="CustomerFaxLabel" runat="server" Text="Fax" />
            <asp:TextBox ID="CustomerFaxValue" runat="server" />
          </div>
          <div>
            <asp:Label ID="CustomerEmailLabel" runat="server" Text="Email" />
            <asp:TextBox ID="CustomerEmailValue" runat="server" />
          </div>
          <div>
            <asp:Label ID="CustomerWebLabel" runat="server" Text="Web" />
            <asp:TextBox ID="CustomerWebValue" runat="server" />
          </div>
        </div>
      </div>
      <div class="update_button_field">
        <asp:Button ID="UpdateContactDetailsButton" runat="server" Text="Update" 
          onclick="UpdateContactDetailsButton_Click" />
      </div>          
    </ContentTemplate>    
  </asp:UpdatePanel>

Thanks in advance.

NOTE: To be able to understand the progress on this problem, please see the comments on this answer before replying.

UPDATE
I have implemented a temporary solution to this problem by putting a check in javascript that if the script is already executing then do not execute twice. Javascript is still being spitted multiple times on every partial postback. Couldn't prevent it.

As the views to this post are increasing, I can see that there are other people who might also want answer to this problem.

Answer 1

If you are using this;

Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "noPasswordMatch", script, true);

Then to check if it has been registered you must use this:

if (Page.ClientScript.IsClientScriptBlockRegistered(this.GetType(), "noPasswordMatch"))

if (Page.ClientScript.IsClientScriptBlockRegistered("noPasswordMatch")) doesn't work!

Answer 2

I ran into this same issue when writing a composite control in ASP.Net. When the control was inside an update panel Page.ClientScript.IsStartupScriptRegistered didnt work. From within the method protected override void CreateChildControls() i was doing something like

ScriptManager.RegisterStartupScript(this.Page, this.Page.GetType(), initializeTokenInputScriptKey, initializeTokenInputScript, true);

Hence I ran into a situation similar to what you describe here. What solved my problem was passing the control and its type instead of the page and page type to ScriptManager.RegisterStartupScript. Hence the code now looks,

ScriptManager.RegisterStartupScript(this, this.GetType(), initializeTokenInputScriptKey, initializeTokenInputScript, true);

Once I did this change I no longer needed to check Page.ClientScript.IsStartupScriptRegistered. Now my control works with or without update panels. No unnecessary js spitouts either. Hope this helps

Answer 3

I had implemented a temporary solution to this problem by putting a check in javascript that if the script is already executing then do not execute twice. Javascript is still being spitted multiple times on every partial postback. Couldn't prevent it.

Answer 4

I've written an extension method to check whether the script has already been registered with the ScriptManager. You can use the same principle to check startup scripts:

public static bool IsClientScriptBlockRegistered(this ScriptManager sm, string key)
        {
            ReadOnlyCollection<RegisteredScript> scriptBlocks = sm.GetRegisteredClientScriptBlocks();

            foreach (RegisteredScript rs in scriptBlocks)
            {
                if (rs.Key == key)
                    return true;
            }

            return false;
        } 

Answer 5

Keep in mind your first line of code is the inverse of the method return value because of the !.

if (!Page.ClientScript.IsStartupScriptRegistered(Page.GetType(), scriptKey))

If IsStartupScriptRegistered is returning false as you say, then the if statement should evaluate true because of the !. This should cause the script to be registered as expected.

Your code is based on my answer here, which was based on ASP.NET AJAX 1.0 and ASP.NET 2.0. It may have something to do with .NET 3.5, although I believe I've used the above already in a newer project we did under 3.5 and it worked fine...

Can you post some markup to go with the code?

EDIT: Thanks for posting the markup.

I notice 2 things now:

You mentioned you are using ToolkitScriptManager. It is a control that inherits from ScriptManager. I didn't notice this before, but your code is still referencing ScriptManager directly. You said it was during async postbacks that the script isn't working, which leads me to believe it is an issue with your reference to ScriptManager. I've never used ToolkitScriptManager before so I can't give you exact code, but I can tell you that you'll likely need to update your code-behind, changing all references to ScriptManager and its methods/properties to the equivalent in ToolkitScriptManager.

Try adding a breakpoint on the if statement and make sure it's evaluation to true. I wouldn't be surprised if scriptManager is null, or scriptManager.IsInAsyncPostBack is false because you're using ToolkitScriptManager.

ScriptManager scriptManager = ScriptManager.GetCurrent(page);
if (scriptManager != null && scriptManager.IsInAsyncPostBack)
{
  //if a MS AJAX request, use the Scriptmanager class
  ScriptManager.RegisterStartupScript(Page, Page.GetType(), scriptKey, script, true);
}

Lastly - Your markup looks okay, other than you don't need the <Triggers> section. Triggers allow you to specify control which are outside of your update panel to cause partial renders. Any child control of the update panel within the <ContentTemplate> section will do this automatically. The button you are targeting in the Triggers section is already within the updatepanel. While I don't think this is the cause of your issue, I'd remove it anyway.

Hope this helps.

Answer 6

Did you mean this: ClientScriptManager.IsStartupScriptRegistered Method