ASP.NET Multiple Page_Load events with URL Rewriting

Question

Hello All,

Im using intelligencia urlrewriter as my url rewrite module. I have one very strange problem which only occurs when an url is rewritten but to make it more fun, not on all rewritten pages.

Edit: Forgot to tell you what's the problem boing boing. the problem is that my Page_Load event gets fired 2 times.

This is how my form rewrite adapter looks like:

using System;

using System.Web.UI; using System.Web; using System.Web.UI.WebControls;

public class FormRewriterControlAdapter : System.Web.UI.Adapters.ControlAdapter {

protected override void Render(System.Web.UI.HtmlTextWriter writer)
{

    base.Render(new RewriteFormHtmlTextWriter(writer));

}

}

public class RewriteFormHtmlTextWriter : HtmlTextWriter {

public RewriteFormHtmlTextWriter(HtmlTextWriter writer)
    : base(writer)
{
    this.InnerWriter = writer.InnerWriter;
}

public RewriteFormHtmlTextWriter(System.IO.TextWriter writer)
    : base(writer)
{
    base.InnerWriter = writer;
}

public override void WriteAttribute(string name, string value, bool fEncode)
{

    // If the attribute we are writing is the "action" attribute, and we are not on a sub-control, 
    // then replace the value to write with the raw URL of the request - which ensures that we'll 
    // preserve the PathInfo value on postback scenarios 

    if ((name == "action"))
    {

        HttpContext Context = default(HttpContext);
        Context = HttpContext.Current;

        if (Context.Items["ActionAlreadyWritten"] == null)
        {

            // Because we are using the UrlRewriting.net HttpModule, we will use the 
            // Request.RawUrl property within ASP.NET to retrieve the origional URL 
            // before it was re-written. You'll want to change the line of code below 
            // if you use a different URL rewriting implementation. 

            value = Context.Request.RawUrl;

            // Indicate that we've already rewritten the <form>'s action attribute to prevent 
            // us from rewriting a sub-control under the <form> control 

            Context.Items["ActionAlreadyWritten"] = true;
        }

    }


    base.WriteAttribute(name, value, fEncode);

}

}

And this is how my web.config looks like

        <!-- Here the double page_load occurs  --> 
    <rewrite url="~/car-parts/(\d+)/(.+)" to="~/Products.aspx?type=parts&amp;iid=$1&amp;cid=9" />
    <rewrite url="~/car-stereo/(\d+)/(.+)" to="~/Products.aspx?type=stereo&amp;iid=$1&amp;cid=10" />



    <!-- this is working correctly -->
     <rewrite url="~/car-parts/browse-by-type/(\d+)/(.+)/(\d+)/(\d+)" to="~/Browse.aspx?cid=9&amp;type=country&amp;countryid=$1&amp;p=$3&amp;filter=$4" />

I have no idea where to look anymore, i checked my html markup since i've read that could couse this problem.

Kind regards, Mark

Answer 1

I wrote two short blog posts on UrlRewriting that might help

1. Part One
2. Part Two

Answer 2

Finally I found it, it was not having anything to do with the rewrite module , this is which caused the problem:

In one of my usercontrols i've used updateprogress

    <asp:UpdateProgress runat="server" AssociatedUpdatePanelID="upNewsletter" DisplayAfter="0">
    <ProgressTemplate>
        <asp:Image runat="server" ID="imgLoading" ImageUrl="~/Images/Template/loading.gif" />
    </ProgressTemplate>
</asp:UpdateProgress>

Now thats where the problem is , in the asp:Image tag. I've replaced it with a regular img tag and now everything works fine again. Took me some time to figure this out and I hope I can save you headache.

Kind regards

Answer 3

I've found this post searching for multiple page_loads, but I had the problem using a dynamically created CollapsePanel using a dynamically created Image. By filling the ImageUrl to a default image, the problem was solved.

header.Controls.Add( new Image
{
    ID = string.Format( "headerImage_{0}",  panelId ),
    EnableViewState = false,
    ImageUrl = "~/Images/collapse.jpg"
} );