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ASP.NET which control could wrap JS block and extractable so I could render it back to header

Answer 1

A:

<%@ Page Language="C#"%>
<script runat=server>
    protected override void OnLoad(EventArgs e)
    {
        string scriptText = someID.InnerHtml;
        //if you really want it in the header...
        //Page.Header.Controls.Add( new LiteralControl(String.Format( "<scr" + "ipt language=\"javascript\">{0}</scri" + "pt>\\n", scriptText )));

        //doesnt add to header and requires form runat=server
        Page.ClientScript.RegisterStartupScript(this.GetType(), "SomeScript", scriptText, true);

        base.OnLoad(e);
    }
</script>
<head runat=server></head>
<form runat=server>
<div id="someID" runat=server>alert('hi');</div>
</form>

Chad Grant 2009-05-10 11:14:44

I think it would blow when you try to get InnerHtml, thats the same case as what I did- you tried?

goodwill 2009-05-10 17:04:24

it works when i tested it

Chad Grant 2009-05-11 04:07:53

I mean, the Page.Header.Controls.Add part, the part you commented seems wont work IIRC.

goodwill 2009-07-10 03:50:01

it requires the <head runat="server">, but that is production code, so it definitely works

Chad Grant 2009-07-10 23:52:12

Answer 2

+1 A:

You could store the javascript in a separate file, and then add it to the page using Page.RegisterClientScriptBlock()

Add the javascript you want to a .js file and add the .js file to your project. Alter the properties of the .js file so that it is an Embedded Resource.

Then use code like this somewhere in your UserControl (maybe the Page_Load) to pull the code from the file and drop it into the page:

string javaScript = "";
// the javascript is in a separate file which is an 'embedded resource' of the dll
using (StreamReader reader = 
    new StreamReader((typeof(ThisClass).Assembly.GetManifestResourceStream(typeof(ThisClass), "NameOfJavaScriptFile.js"))))
{
    javaScript = String.Format("<script language='javascript' type='text/javascript' >\r\n{0}\r\n</script>", reader.ReadToEnd());
}
Page.RegisterClientScriptBlock("MyScriptBlock", javaScript);

Note that RegisterClientScriptBlock() will put the script near the top of the page, but apparently not in the page header.

(edited bit about header after comment)

codeulike 2009-05-10 11:56:35

This wont be put on header AFAIK. The page client script block just throw stuff into the page at the time you call- thats something I hate a lot in ASP.NET. Without exception all JS should stay inside head, thats especially true for me because I am using jQuery to do method hook.

goodwill 2009-05-10 17:02:04

ah your right, RegisterClientScriptBlock() is supposed to put the scripts near the start of the page, but it doesn't actually put them in the header. i have edited my answer accordingly

codeulike 2009-05-10 17:33:03

Answer 3

A:

Okay, I've probably done this in a horrible, horrible way, but I wanted to add a script to the head element in a recent project from a user control. This script didn't require any data from my server, but I only wanted it on specific pages, so I put the script in a .js-file, and added it to the head like this:

HtmlGenericControl script = new HtmlGenericControl("script"); // Creates a new script-element
script.Attributes.Add("type","text/javascript");
script.Attributes.Add("src","src/to/js-file.js");
Page.Master.FindControl("head").Controls.Add(script); // Finds the element with ID "head" on the pages master page.

Not entirely sure if the code works as I think it does as the code I wrote for the project is on another machine, but you get the idea, right?

Edit: After googling your error message for a bit, I think this might be a solution to your problem:

using System.IO;

StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
yourDivID.RenderControl(h);
String str = sw.GetStringBuilder().ToString();

If you combine the two examples, you should be able to get the result you want. I haven't tested this, but it works in my head.

Jesper Karsrud 2009-05-11 00:13:14

The problem is the script I intend to put on header have some dynamic code needs to be generated runtime on server (e.g. Fill in control id) so including a file is not an option.

goodwill 2009-05-11 02:18:16

I see. I've added another snippet that might help you.

Jesper Karsrud 2009-05-11 08:30:25

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ASP.NET which control could wrap JS block and extractable so I could render it back to header

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