PageRequestManager only processes one asynch callback at a time?

I was under the impression that the asp.net ajax framework was capable of handling multiple asynch callbacks simultaneously and processing the results of each in the order that they come back. However, I accidentally discovered something interesting: it seems that if you begin an asynch callback from the browser while a previous asynch callback is still in process, the first one gets cancelled by the client-side PageRequestManager instance before it begins the second one.

To see what I'm talking about, you can go to this official MS ajax example:http://ajax.asp.net/docs/Samples/System.Web.UI.UpdateProgress1/cs/Default.aspx

Try clicking the first button, then quickly clicking the second button before the first date gets updated on the page. Notice that after a few seconds, the second date changes as a result of the second asynch callback, but the first date never gets updated. This is because the asp.net ajax framework is prematurely ending the first request as soon as you initiate the second request by clicking the second button.

I'm working on a project with multiple UpdatePanels on a page that do completely separate things in their server-side code, and ideally we would like the user to be able to initiate a callback in one panel and then immediately initiate a callback in the second panel, and have both of the asynchronous callbacks processing at the same time. At the moment, it doesn't seem like this is a possibility in the asp.net ajax framework.

If anybody can tell me how I might be able to get around this issue I would be very appreciative.

hello.

well, what you ask isn't doable with the current code of the platform. you can only have more than one remote call if you're using web services (and even in these cases you might face some problems which have been described here: http://www.codeproject.com/Ajax/aspnetajaxtips.asp)

PageRequestManagerParserErrorException with the Update Panel

I have spent quite a bit of time researching this and I cannot figure it out. So if there is anybody that has any ideas I am all ears.

I have a pretty simple site that uses a few update panels. I am developing with VS2005 on XP all the patches and using ASP.NET AJAX 1.0. Everything works perfect on my dev machine and on second beta server I have. When everything get moved to the client site they get the "PageRequestManagerParserErrorException" error on the pages with the update panel. I am not using server.transfer or respnse.write() or any other known issues. The client machine is a test box that was imaged for this app. Running Win2003 all clean and up to date in a pretty standard configuration.

I am just looking for direction: I saw some posts about response caching and machinekey but I have no idea what to look for or what to direct the sys admin to look for.

Any help would be greatly appreciated.

Craig.

Have a look here for troubleshooting tips:http://weblogs.asp.net/leftslipper/archive/2007/02/26/sys-webforms-pagerequestmanagerparsererrorexception-what-it-is-and-how-to-avoid-it.aspx

Also see this related post:http://forums.asp.net/p/1038252/1439637.aspx

Hope these help...

-Damien

Damien,

Thanks for the links. In my searching I did come accross them (and meany others). So I threw up a server outside of my network that and tried to hit the pages with an update panel again. And this time I get the error (sometimes). It was strange that I would sometimes get an error and others I wouldn't. So I installed fiddler to see what the response was like. When I get an error I notice this in the respose;

[HttpException (0x80004005): Server cannot modify cookies after HTTP headers have been sent.]
System.Web.HttpCookieCollection.Add(HttpCookie cookie) +103
System.Web.Security.RoleManagerModule.OnLeave(Object source, EventArgs eventArgs) +650
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +92
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64

I am using a master page that will show differnt information based on the user's role. My guess is that the injection of this error into the response is causing the problem because when it works there is no error. Unfortunatly I don't know what this means yet. Guess it's back to the internet for some studying.

If anybody has any sugestions or direction on addressing this issue I would welcome the advice.

Regards,

Craig

Got it!

This link was the answerhttp://forums.asp.net/p/1069056/1556225.aspx#1556225

I still need to read up on the issue but the answer was to set the cacheRolesInCookie=false in the web.config file. Made the change and all is good. Although, I now wonder what the impact is now on perfomance.

Craig

PageRequestManagerServerErrorException error code 12002

Hi , i'm having this problem, i need to run an store procedure from a aspx page and i'm having this error. It seems that is an request time out. The Procedure last almost 1 hour and 15 minutes. Please help me.

the message i have is ... and it's shown by the 60 minute of execution.

I'm using Ajax v 1.0. , ScriptManager and UpdatePanel.

Sys.WebForms.PageRequestManagerServerErrorException: An unknown error ocurred while processing the request
on the server. The status code reutrned from the server was: 12002

Hi Tony,

You can set the AsyncPostBackTimeout property of the ScriptManager. In your scenario, you can define it to be about 1 hour and a half (5400 secs).
Just make sure that the other time-out variables (session, forms authentication cookie and roles cookie) are not interfering as well.

Also, check the httpRuntime executionTimeout property if you are working with file uploads.

I hope this helps,

Juan

Hi Tony, I am facing same problem, PageRequestManagerServerErrorException error code 12002 exception. My procedure takes apprx 2hrs to run..

goyou have got any solution please pass it to me atshiekh.Bilal@.gmail.com

Thanks

Bilal

Hi Tony, I am facing same problem, PageRequestManagerServerErrorException error code 12002 exception. My procedure takes apprx 2hrs to run.. goyou have got any solution please pass it to me atshiekh.Bilal@.gmail.com

Thanks Bilal

PageRequestManagerServerErrorException with error code 500

I am working on an ASP.NET AJAX web application. I got a PageRequestManagerServerErrorException with error code 500 every time when I try to populate a text box with a string contains some HTML tags (like <BR> for example). The full error message "Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 500" appears in an alert box from javascript.
The main problem is that every next async post back generates the same error on the client side. Of course, I can check the passing string preliminarily, but my question is:
Is there a way to handle an error like this so the web application continues to run?
I have already check to clear error in Application Context on Application_Error event with Context.ClearError(), but it does not affect.

Hi!,

That exception is a callback exception and the PageRequestManager is the AJAX ScriptManager control.

You could customize the callback errors using the AsyncPostBackErrorMessage property of the ScriptManager.

Also, if you want to handle the error on server-side, use the ScriptManager_AsyncPostBackError event.

Please refer to this:http://support.microsoft.com/kb/193625

Check this articlehttp://blog.g9th.com/2007/01/14/unable-to-validate-data-at-systemwebconfigurationmachinekeysectiongetdecodeddata.aspx

Let me know if you need more info.
You can also see this thread for more help:http://forums.asp.net/t/1115331.aspx

Hi chetan.sarode!

Thank you for your post.

Yesterday I tried to handle this error on ScriptManager_AsyncPostBackError event, but unfortunately it doesn't fire.

The only one event I found to handle is Application_Error on Global.asax. I could ClearError in current HttpContext, but it doesn't affect on client side. The error still apears after every next async post back (the only difference is that alert box in javascript with the error message doesn't appear).

So, is there a way to prevent the response from the server to the client in that case. I mean it is better for me, the server sends nothing to the client instead of an error that stops every next async post back.

I appreciate any advice.

Thanks again.

I will look into that more...

Will let u know

Hi,

I got the same error a few days ago.

The following is my code that got the error:

<%@. Page Language="C#" %>

<%@. Import Namespace="System.Xml" %>
<%@. Import Namespace="System.Data" %>
<%@. Import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text = DateTime.Now.ToString();

//string strxml = "<books><book>asp</book><book>asp1</book><book>asp2</book></books>";
string strxml = HiddenField1.Value;//.Replace("begin", "<").Replace("end", ">").Replace("slash", "/");
//DataSet myDS = new DataSet();
//XmlTextReader xtr = new XmlTextReader(new StringReader(strxml));
//myDS.ReadXml(xtr);
//DropDownList1.DataSource = myDS;
//DropDownList1.DataValueField = "book";
//DropDownList1.DataTextField = "book";

System.Xml.XmlDocument sa = new System.Xml.XmlDocument();
sa.LoadXml(strxml);
System.Xml.XmlNodeList saa = sa.GetElementsByTagName("book");
DropDownList1.DataSource = saa;
DropDownList1.DataValueField = "InnerText";
DropDownList1.DataTextField = "InnerText";

DropDownList1.DataBind();
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>

<script language="javascript" type="text/javascript">
// <!CDATA[

function Button2_onclick() {
document.getElementById("HiddenField1").value = test.XMLDocument.xml;
// var a = "";
// while(document.getElementById("HiddenField1").value != a){
// var a = document.getElementById("HiddenField1").value;
// document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace("<","begin");
// document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace("/","slash");
// document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace(">","end");
// }
document.getElementById("Button1").click();
}

// ]]>
</script>

</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList><div style="visibility: hidden">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
</div>
<input id="Button2" type="button" value="button" onclick="return Button2_onclick();" />
<asp:HiddenField ID="HiddenField1" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
<xml id="test">
<books>
<book>asp</book>
<book>asp1</book>
<book>asp2</book>
</books>
</xml>
</form>
</body>
</html>

I resolved it by changing the code into the following code:

<%@. Page Language="C#" %>

<%@. Import Namespace="System.Xml" %>
<%@. Import Namespace="System.Data" %>
<%@. Import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text = DateTime.Now.ToString();

//string strxml = "<books><book>asp</book><book>asp1</book><book>asp2</book></books>";
string strxml = HiddenField1.Value.Replace("begin", "<").Replace("end", ">").Replace("slash", "/");

//DataSet myDS = new DataSet();
//XmlTextReader xtr = new XmlTextReader(new StringReader(strxml));
//myDS.ReadXml(xtr);
//DropDownList1.DataSource = myDS;
//DropDownList1.DataValueField = "book";
//DropDownList1.DataTextField = "book";

System.Xml.XmlDocument sa = new System.Xml.XmlDocument();
sa.LoadXml(strxml);
System.Xml.XmlNodeList saa = sa.GetElementsByTagName("book");
DropDownList1.DataSource = saa;
DropDownList1.DataValueField = "InnerText";
DropDownList1.DataTextField = "InnerText";

DropDownList1.DataBind();
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>

<script language="javascript" type="text/javascript">
// <!CDATA[

function Button2_onclick() {
document.getElementById("HiddenField1").value = test.XMLDocument.xml;
var a = "";
while(document.getElementById("HiddenField1").value != a){
var a = document.getElementById("HiddenField1").value;
document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace("<","begin");
document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace("/","slash");
document.getElementById("HiddenField1").value = document.getElementById("HiddenField1").value.replace(">","end");
}
document.getElementById("Button1").click();
}

// ]]>
</script>

</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
<asp:DropDownList ID="DropDownList1" runat="server">
</asp:DropDownList><div style="visibility: hidden">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
</div>
<input id="Button2" type="button" value="button" onclick="return Button2_onclick();" />
<asp:HiddenField ID="HiddenField1" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
<xml id="test">
<books>
<book>asp</book>
<book>asp1</book>
<book>asp2</book>
</books>
</xml>
</form>
</body>
</html>

For more information,seehttp://forums.asp.net/t/1126640.aspx(embedded xml datasource)

Thanks

Panel or Multiview inside Updatepanel, whats faster?

So I have multiple gridviews to display on a single page. There are multiple ways to display these one at a time. The first would, of course, be a multiview, the second, a set of panels using the visible attrib to control the views. Normally, a multiview would be a great way to do this, but when one adds an update panel what is best way to build the page when render speed is considered.

The multiview must, of course, sit in one updatepanel, therefore making the page render the entire section of code on each async postback. This would mimic the behavior of putting all the panels in one updatepanel. However, when one puts each panel inside its own updatepanel, it would seem to me that rendering would speed up, since the asyncpostback only has to return HTML related to its own individual gridview.

Anyone have any ideas on this?

Also, sort of related to this:

When all the panels are inside a table cell <td> and right on top of each other, so:

<td>

<asp:updatepanel id="test" runat="server">

<contenttemplate>

<panel id="pnl1" runat="server">

stuff

</panel>

</contenttemplate>

</asp:updatepanel>

<asp:updatepanel id="test2" runat="server">

<contenttemplate>

<panel id="pnl2" runat="server">

stuff

</panel>

</contenttemplate>

</asp:updatepanel>

</td>

When the first panel or pnl1 is rendered visible=false, the second panel pushes down the screen about 30px, yet when I remove the updatepanels, the panel shows up without the 30px push. I have not really investigated this too much, but if someone has seen this type of issue and knows a quick fix, I would be appreciative.

THanks

Jason

I think all in all they will render about the same amount of HTML - and the server side processing should be the same with both. If anything the multi-view will be a bit slower due to the extra-overhead the control might have - but i'm talking miliseconds or smaller.

Remember when a panel has visible=False - nothing inside that panel is rendered to the clients computer.

regarding the push down - have you looked with the developer tools in IE / FireFox to see what block element is pushing it down?

Sounds good. I'll just go w/the multiview then and make life a bit easier, this will solve the 30px push as well so I will mark this as solved.

ParserErrorException when Edit button on Datagrid pressed

I have a datagrid control wrapped in an UpdatePanel. There are Edit/Delete ImageButton's for each row. The first time I press the Edit butonn (setsEditItemIndex = -1) the ubiquitous Sys.Webforms.PageRequestManagerParserErrorException; The message from the server could not be parsed...

Subsequently, pressing the edit button prooduces the desired results.

Any ideas with this strange behavior are appreciated.

TIA

Hi,

Please refer to this:http://siderite.blogspot.com/2007/02/aspnet-ajax-and-responsewrite-or.html

It gives a full explanation of it. Hope this helps.

NOTE:This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.

I also face this kind of problem - 'Sys.WebForms.PageRequestManagerPerserErrorException:'. So far I
understand this happen when there is some unrecongnize html render or event occurs. I'm also not very clear.

But I solve the issue by set the attribute EnableEventValidation="false" in the ASPX page, where I place my
UpdatePanel.

Thanks
I also face this kind of problem - 'Sys.WebForms.PageRequestManagerPerserErrorException:'. So far I
understand this happen when there is some unrecongnize html render or event occurs. I'm also not very clear.

But I solve the issue by set the attribute EnableEventValidation="false" in the ASPX page, where I place my
UpdatePanel.

Thanks

Partial Postbacks and JScript Changes Previously Made on the Client Side

Hello, thank you in advance for taking the time to read this.

I have a Gridview on which I use client-side JScript to add an empty row (hidden) after binding. I place several hidden DIVS in my Gridview template, and then when a user clicks on one of several "expand" buttons in the Gridview, the empty row is made visible and the innerHTML is swapped from the appropriate hidden DIV. This makes the empty row sort of a "Jack of all trades" in that it can display numerous different things as needed by the user.

I am attaching the JScript function below for reference. The empty DIVS are inserted into the client page in the Codebehind using the Gridview's OnRowDataBound handler, but I have no clue how to add a row dynamically server-side, so I went with the client-side script to get the container row done.

Everything works great until you do a sort. The control is AJAX-enabled, so refreshes through a partial postback. Trouble is that the client-side code that adds all the rows does not fire when the grid is refreshed, so none of the "Expand" icons work after the Gridview has been refreshed, because there is no hidden row to make visible and swap content with.

After all this, my question is: How might I:

A) insert an empty row programatically server-side, or

B) fire a client-side script at databinding on a partial postback.

Oh, and I am a pure short-busser when it comes to .NET -- love it but am just now moving up from legacy and feel like a complete idiot. Please speak slowly if you care to answer, and forgive my ignorance.

Javascript adding the rows follows -- I am assigning an ID reference to each row using the "Tracking" field - a unique DB column.

Thanks again for reading, and for any information or hlp you can provide.

Shannon

function fixGrid(idGrid){

var al ="";

var rowcount = 0;for (var t=0;t<idGrid.childNodes[0].childNodes.length-1;t++){

thisName = idGrid.childNodes[0].childNodes[t].nodeName;

if(thisName=="TR"){

rowcount ++;

if(rowcount > 1){

lastCell = idGrid.childNodes[0].childNodes[t].childNodes.length;

thisCell = idGrid.childNodes[0].childNodes[t].childNodes[lastCell-1];

thisTrack = idGrid.childNodes[0].childNodes[t].childNodes[lastCell-2].innerText;

newTR = document.createElement('tr');

newRow1 = newTR.cloneNode(true);

newTD = document.createElement('td');newCol1 = newTD.cloneNode(true);

newCol1.colSpan=9;

newCol1.style.visibility='hidden';

newCol1.style.display='none';

newCol1.id ="td-"+thisTrack;

newCol1.innerHTML="Nothing";

newTR.appendChild(newCol1);

nextRow = idGrid.childNodes[0].childNodes[t].nextSibling;

tableTop = idGrid.childNodes[0].childNodes[t].parentNode;

tableTop.insertBefore(newTR,nextRow);

t++;

}

}else{

alert(thisName);

}

}

returnfalse;

}

Problem solved! I figured I would answer myself for the benefit of future readers.

The call to the client side code in my original post is made fromfixGrid(document.all.gridedit)when the page originally loads.

Obviously, I only want to add the empty container rows once, so I only want this script to be called once each time UpdatePanel1 refreshes, and not if any other panel does. Got it to work that way usingRegisterClientScriptBlock with the update panel ID:

protectedvoid Page_PreRender(object sender,EventArgs e)

{

string script =@."fixGrid(document.all.gridedit);";ScriptManager.RegisterClientScriptBlock(

UpdatePanel1,

typeof(Page),

"ToggleScript",

script,

true);

}