[c#] Can't get ScriptManager.RegisterStartupScript in WebControl nested in UpdatePanel to work

I am having what I believe should be a fairly simple problem, but for the life of me I cannot see my problem. The problem is related to ScriptManager.RegisterStartupScript, something I have used many times before.

The scenario I have is that I have a custom web control that has been inserted into a page. The control (and one or two others) are nested inside an UpdatePanel. They are inserted onto the page onto a PlaceHolder:

<asp:UpdatePanel ID="pnlAjax" runat="server">
  <ContentTemplate>
    <asp:PlaceHolder ID="placeholder" runat="server">
    </asp:PlaceHolder>
    ...

protected override void OnInit(EventArgs e){
  placeholder.Controls.Add(Factory.CreateControl());
  base.OnInit(e);
}

This is the only update panel on the page.

The control requires some initial javascript be run for it to work correctly. The control calls:

ScriptManager.RegisterStartupScript(this, GetType(), 
                                    Guid.NewGuid().ToString(), script, true);

and I have also tried:

ScriptManager.RegisterStartupScript(Page, Page.GetType(), 
                                    Guid.NewGuid().ToString(), script, true);

The problem is that the script runs correctly when the page is first displayed, but does not re-run after a partial postback. I have tried the following:

1. Calling RegisterStartupScript from CreateChildControls
2. Calling RegisterStartupScript from OnLoad / OnPreRender
3. Using different combinations of parameters for the first two parameters (in the example above the Control is Page and Type is GetType(), but I have tried using the control itself, etc).
4. I have tried using persistent and new ids (not that I believe this should have a major impact either way).
5. I have used a few breakpoints and so have verified that the Register line is being called correctly.

The only thing I have not tried is using the UpdatePanel itself as the Control and Type, as I do not believe the control should be aware of the update panel (and in any case there does not seem to be a good way of getting the update panel?).

Can anyone see what I might be doing wrong in the above?

Thanks :)

Well, to answer the query above - it does appear as if the placeholder somehow messes up the ScriptManager.RegisterStartupScript.

When I pull the control out of the placeholder and code it directly onto the page the Register script works correctly (I am also using the control itself as a parameter).

ScriptManager.RegisterStartupScript(this, GetType(), Guid.NewGuid().ToString(), script, true);

Can anyone throw any light on why an injected control onto a PlaceHolder would prevent the ScriptManager from correctly registering the script? I am guessing this might have something to do with the lifecycle of dynamic controls, but would appreciate (for my own knowledge) if there is a correct process for the above.

When you call ScriptManager.RegisterStartupScript, the "Control" parameter must be a control that is within an UpdatePanel that will be updated. You need to change it to:

ScriptManager.RegisterStartupScript(this, this.GetType(), Guid.NewGuid().ToString(), script, true);

The solution is to put the scripts in an outside js file (lets called 'yourDynamic.js') and re-register de file everytime you refresh the updatepanel.

I use this in the updatepanel_prerender event:

ScriptManager.RegisterClientScriptBlock(UpdatePanel1, UpdatePanel1.GetType(), "UpdatePanel1_PreRender", _
                   "<script type='text/javascript' id='UpdatePanel1_PreRender'>" & _
                   "include('yourDynamic.js');" & _
                   "removeDuplicatedScript('UpdatePanel1_PreRender');</script>" _
                   , False)

In the page or in some other include you will need this javascript:

// Include a javascript file inside another one.
function include(filename)
{
    var head = document.getElementsByTagName('head')[0];

    var scripts = document.getElementsByTagName('script');
    for(var x=0;x<scripts.length;>    {
        if (scripts[x].getAttribute('src'))
        {
            if(scripts[x].getAttribute('src').indexOf(filename) != -1)
            {
                head.removeChild(scripts[x]);
                break;
            }
        }
    }

    script = document.createElement('script');
    script.src = filename;
    script.type = 'text/javascript';
    head.appendChild(script)
}

// Removes duplicated scripts.
function removeDuplicatedScript(id)
{
    var count = 0;
    var head = document.getElementsByTagName('head')[0];

    var scripts = document.getElementsByTagName('script');
    var firstScript;
    for(var x=0;x<scripts.length;>    {
        if (scripts[x].getAttribute('id'))
        {
            if(scripts[x].getAttribute('id').indexOf(id) != -1)
            {
                if (count == 0)
                {
                    firstScript = scripts[x];
                    count++;
                }
                else
                {
                    head.removeChild(firstScript);
                    firstScript = scripts[x];
                    count = 1;
                }
            }
        }
    }
    clearAjaxNetJunk();
}
// Evoids the update panel auto generated scripts to grow to inifity. X-(
function clearAjaxNetJunk()
{
    var knowJunk = 'Sys.Application.add_init(function() {';
    var count = 0;
    var head = document.getElementsByTagName('head')[0];

    var scripts = document.getElementsByTagName('script');
    var firstScript;
    for(var x=0;x<scripts.length;>    {
        if (scripts[x].textContent)
        {
            if(scripts[x].textContent.indexOf(knowJunk) != -1)
            {
                if (count == 0)
                {
                    firstScript = scripts[x];
                    count++;
                }
                else
                {
                    head.removeChild(firstScript);
                    firstScript = scripts[x];
                    count = 1;
                }
            }
        }
    }
}

Pretty cool, ah...jejeje This part of what i posted some time ago here.

Hope this help... :)

Sometimes it doesnt fire when the script has some syntax error, make sure the script and javascript syntax is correct.

I try many things and finally found that the last parameter must be false and you must add <SCRIPT> tag to the java script :

string script = "< SCRIPT >alert('hello!');< /SCRIPT>";

ScriptManager.RegisterClientScriptBlock(Page, Page.GetType(), key, script, **false**);

I had an issue with Page.ClientScript.RegisterStartUpScript - I wasn't using an update panel, but the control was cached. This meant that I had to insert the script into a Literal (or could use a PlaceHolder) so when rendered from the cache the script is included.

A similar solution might work for you.

I had an issue using this in a user control (in a page this worked fine); the Button1 is inside an updatepanel, and the scriptmanager is on the usercontrol.

protected void Button1_Click(object sender, EventArgs e)  
{  
    string scriptstring = "alert('Welcome');";  
    ScriptManager.RegisterStartupScript(this, this.GetType(), "alertscript", scriptstring, true);  
}

Now it seems you have to be careful with the first two arguments, they need to reference your page, not your control

ScriptManager.RegisterStartupScript(this.Page, this.Page.GetType(), "alertscript", scriptstring, true);

ScriptManager.RegisterStartupScript(this, this.GetType(), Guid.NewGuid().ToString(),script,  true );

The "true" param value at the end of the ScriptManager.RegisterStartupScript will add a JavaScript tag inside your page:

<script language='javascript' defer='defer'>your script</script >

If the value will be "false" it will inject only the script witout the --script-- tag.

DO NOT Use GUID For Key

ScriptManager.RegisterClientScriptBlock(this.Page, typeof(UpdatePanel) 
       Guid.NewGuid().ToString(), myScript, true);

and if you want to do that , call Something Like this function

 public static string GetGuidClear(string x)
 {
      return x.Replace("-", "").Replace("0", "").Replace("1", "")
              .Replace("2",  "").Replace("3", "").Replace("4", "")
              .Replace("5", "").Replace("6", "").Replace("7", "")
              .Replace("8", "").Replace("9", "");
 }

What worked for me, is registering it on the Page while specifying the type as that of the UpdatePanel, like so:

ScriptManager.RegisterClientScriptBlock(this.Page, typeof(UpdatePanel) Guid.NewGuid().ToString(), myScript, true);