ASP.NET AJAX Discussion and Suggestions

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

CitizenBane — Thu, 08 May 2008 15:55:12 GMT

Just to make sure there's no more confusion for any VB.NET folks that are reading this thread:

I added the following javascript to all of my Master Pages, right before the the </body> tag:

<script type="text/javascript">
function beginRequest(sender, args) {
   var r=args.get_request();
   if (r.get_headers()["X-MicrosoftAjax"])
   {
    b=r.get_body();
    var a="__MicrosoftAjax=" + encodeURIComponent(r.get_headers()["X-MicrosoftAjax"]);
    if (b!=null && b.length>0)
    {
	b+="&";
    }
    else
	b="";
    r.set_body(b+a);
   }       
}
Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
</script>

After that, I added the following VB.NET code to my Global.asax file, in the Application_BeginRequest method:

If (request.Headers("X-MicrosoftAjax") = Nothing) And (Not request.Form("__MicrosoftAjax") = Nothing) Then
   Dim list As ArrayList = New ArrayList()

   list.Add(request.Form("__MicrosoftAjax"))
   Dim t As Type = request.Headers.GetType()
  
   t.InvokeMember("MakeReadWrite", System.Reflection.BindingFlags.InvokeMethod Or System.Reflection.BindingFlags.NonPublic Or System.Reflection.BindingFlags.Instance, Nothing, request.Headers, Nothing)
   t.InvokeMember("InvalidateCachedArrays", System.Reflection.BindingFlags.InvokeMethod Or System.Reflection.BindingFlags.NonPublic Or System.Reflection.BindingFlags.Instance, Nothing, request.Headers, Nothing)
   t.InvokeMember("BaseSet", System.Reflection.BindingFlags.InvokeMethod Or System.Reflection.BindingFlags.NonPublic Or System.Reflection.BindingFlags.Instance, Nothing, request.Headers, New Object() {"X-MicrosoftAjax", list})          
   t.InvokeMember("MakeReadOnly", System.Reflection.BindingFlags.InvokeMethod Or System.Reflection.BindingFlags.NonPublic Or     System.Reflection.BindingFlags.Instance, Nothing, request.Headers, Nothing)
End If

I hope this eliminates any confusion us VB.NET developers may have.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jpmattis — Fri, 01 Feb 2008 19:28:47 GMT

Great solution! Thank you very much for posting it!

Also, for anyone that plans to implement this code, here are a couple things to be mindful of. The original javascript code that you paste on the pages that are using the update panel has some minor syntax errors that can cause you problems if you don't notice them.

Make sure to put a closing '"' quotation mark on the first <script> tag on the "type" field (it's missing it). Also, on the closing script tag you can remove the "type=text/javascript" portion.

Another thing, if you are using .Net 2.0 with Visual Studio 2005, you have to manully create the global.asax file. For whatever reason, .Net 2.0 with Visual Studio 2005 doesn't make a global.asax file automatically so you have to make it manually yourself, and when you do it makes a scripted file. Remove all the script stuff and link the page directive to a Global.cs file (which you also have to make) that is located in your App_Code directory.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jonelf — Thu, 08 Nov 2007 08:26:36 GMT

It looked really promising until I got:
Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed... Details: Error parsing near 'sdfsdfsdfsdf=|64'.
Where sdfsdfsdf is the end of the ViewState.

Analyzing the responses from the server, first going through the firewall and then while accessing the site directly I notice some small differences.
This a part of the response for direct connection:
Content-Type: text/plain;
charset=utf-8

1c3a5
115566|updatePanel|ctl00_mainPlaceHolder_UpdatePanel2|

and this is while going through the firewall/proxy:
Content-Type: text/plain;
charset=utf-8

115566|updatePanel|ctl00_mainPlaceHolder_UpdatePanel2|

Somehow 1c3a5 has been removed. If anyone of you can tell my why or even what 1c3a5 is in this context you would make my day.

Also if you do have another solution to the problem with firewalls stripping the x-microsoftajax header that would also be very interesing.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 21:54:24 GMT

I just add the script to the end of the page. It works. It's amazing. Thank you very much, sir.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

gunteman — Mon, 05 Nov 2007 21:31:35 GMT

I suggest that you add the script to the end of the page instead (at least the Sys.WebForms.PageRequestManager part), so that the PageRequestManager is properly instantiated. Alos, you should try using Firefox with Firebug, which will allow you to set breakpoints in the Javascript. It makes debugging so much easier.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 19:00:01 GMT

Hi, Thanks for repling. I just debug the code inside the firewall and find that request.headers("X-MicrosoftAjax")="Delta=true". But I also find that

request.Form("__MicrosoftAjax")=nothing, which should be the same value as headers("X-MicrosoftAjax"), at same time. So I just wondering whether I put the JS file in wrong place, which makes the request.Form("__MicrosoftAjax")=nothing. And when I put up the page to live site which is outside the firewall. People get the error message as long as they are in the firewall. Any response will be appreciated

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 18:35:57 GMT

Hi, I just put the JS code into the <head> section of the page which the update panel located in. And I put the server side code in the Global.asax . I don't know whether it is correct or not.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

gunteman — Mon, 05 Nov 2007 18:30:25 GMT

jcai@precisionsupply.com:
Hi, I debug the code inside the firewall and find that:

request.Headers("X-MicrosoftAjax")="Delta=true"

If that's the case then you don't have the mentioned firewall problem.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

gdb_code — Mon, 05 Nov 2007 16:39:38 GMT

Hi, I am having the same issue that one of my customer’s firewalls appears to be preventing the Ajax Update Panels working. I have only used the panels a couple of times within my project. Apologies if it appears a little too obvious, but I am unsure where to paste the original solution code; Global.asax or HttpHandler resides ? Where exactly do I put the code and the procedure definitions to override any default handlers ? Many thanks for any help.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 15:43:00 GMT

Hi, I totally agree with you. But the JS code copy the header(X-MicrosoftAjax) value to

request.Form("__MicrosoftAjax") and submit it to the server. I am just wondering whether I did something wrong with the JS file, which makes

request.Form("__MicrosoftAjax") always be nothing. Thank you.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 15:37:15 GMT

Hi, I totally agree with you. But the JS code copy the value of header("X-MicrosoftAjax") to

request.Form("__MicrosoftAjax") and submit to server. I am just wondering whether I did something wrong with my JS file, which makes

request.Form("__MicrosoftAjax") always be nothing. Thank you.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

Luis Abreu — Mon, 05 Nov 2007 14:42:54 GMT

hello again.

well, but the previous code is no JS code. it's server side code that is supposed to be run on your asp.net server side.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 14:39:38 GMT

Hi, I debug the code inside the firewall and find that:

request.Headers("X-MicrosoftAjax")="Delta=true"

request.Form("__MicrosoftAjax")=Nothing.

Is that because "request.Form("__MicrosoftAjax")=Nothing" causes the problem? I just copy and paste the javascipt code to the page in which the update panel is located. Is it because something I did is wrong? Thanks.

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

Luis Abreu — Mon, 05 Nov 2007 09:42:14 GMT

hello.

have you:

1. debugged tghe code and made sure the code you've written is executed?

2. used fiddler to see what you're getting frmo the database?

Re: Firewall configuration breaking ASP.NET AJAX? What are my options?

jcai@precisionsupply.com — Mon, 05 Nov 2007 02:34:51 GMT

I remove the lock from code. But it still doesn't work. Same error message as before.