|
.net
newsgroups
|
|||||||||||||||||||||||
|
|||||||||||||||||||||||
Problem with RaiseCallbackEventI am getting some strange behavior when using RaiseCallbackEvent. I have a
form that implements ICallbackEventHandler. During the client callback, a session variable is set that is used on the following page load. When debugging through using Visual Studio, everything works fine. When using Firefox, everything works fine. However, when I view the site outside of the debugger in IE, it displays incorrect behavior. The Session variable is set during the client callback, however IE doesn't show that it's actually being set until the Page_render event is fired. Firefox sets the value in the session right away. I need the value to be set right away since controls on the page depend on the vaue in the session variable. By the time Page_render rolls around, the page has already rendered improperly because the session variable hasn't been set. Has anyone else encountered this or have any suggestions? This behavior was not present in beta 2 which the application was originally built in. Small mistake, I meant the the value doesn't get set until the Page_PreRender
event, not the Page_Render event. Show quote "Chris Cap" wrote: > I am getting some strange behavior when using RaiseCallbackEvent. I have a > form that implements ICallbackEventHandler. During the client callback, a > session variable is set that is used on the following page load. When > debugging through using Visual Studio, everything works fine. When using > Firefox, everything works fine. However, when I view the site outside of the > debugger in IE, it displays incorrect behavior. The Session variable is set > during the client callback, however IE doesn't show that it's actually being > set until the Page_render event is fired. Firefox sets the value in the > session right away. I need the value to be set right away since controls on > the page depend on the vaue in the session variable. By the time Page_render > rolls around, the page has already rendered improperly because the session > variable hasn't been set. Has anyone else encountered this or have any > suggestions? This behavior was not present in beta 2 which the application > was originally built in. if you are doing a callback and a submit at the same time then you are in
trouble. they are both async processes, and the browser does not guarantee order. if you are using a session manager, then the server serializes page processing for each session. -- bruce (sqlwork.com) Show quote "Chris Cap" <ccapriccio@newsgroups.nospam> wrote in message news:14BD7187-A6D4-47D4-9520-92B18001BA4C@microsoft.com... >I am getting some strange behavior when using RaiseCallbackEvent. I have a > form that implements ICallbackEventHandler. During the client callback, a > session variable is set that is used on the following page load. When > debugging through using Visual Studio, everything works fine. When using > Firefox, everything works fine. However, when I view the site outside of > the > debugger in IE, it displays incorrect behavior. The Session variable is > set > during the client callback, however IE doesn't show that it's actually > being > set until the Page_render event is fired. Firefox sets the value in the > session right away. I need the value to be set right away since controls > on > the page depend on the vaue in the session variable. By the time > Page_render > rolls around, the page has already rendered improperly because the session > variable hasn't been set. Has anyone else encountered this or have any > suggestions? This behavior was not present in beta 2 which the > application > was originally built in. That may be the case, but it doesn't explain the fact that in .net beta 2
this worked 100 percent of the time in every browser. It also doesn't explain the fact that this works 100 percent of the time in firefox. If this were truly a race condition, it would be present no matter what browser I used and it would occur at random times, not predictably. The value is populated at exactly the same time in the page life cycle which leads me to believe that asychronicty is not the culprit. I appreciate your comment. Are there any other suggestions short of revamping the entire system? Show quote "bruce barker (sqlwork.com)" wrote: > if you are doing a callback and a submit at the same time then you are in > trouble. they are both async processes, and the browser does not guarantee > order. if you are using a session manager, then the server serializes page > processing for each session. > > -- bruce (sqlwork.com) > > "Chris Cap" <ccapriccio@newsgroups.nospam> wrote in message > news:14BD7187-A6D4-47D4-9520-92B18001BA4C@microsoft.com... > >I am getting some strange behavior when using RaiseCallbackEvent. I have a > > form that implements ICallbackEventHandler. During the client callback, a > > session variable is set that is used on the following page load. When > > debugging through using Visual Studio, everything works fine. When using > > Firefox, everything works fine. However, when I view the site outside of > > the > > debugger in IE, it displays incorrect behavior. The Session variable is > > set > > during the client callback, however IE doesn't show that it's actually > > being > > set until the Page_render event is fired. Firefox sets the value in the > > session right away. I need the value to be set right away since controls > > on > > the page depend on the vaue in the session variable. By the time > > Page_render > > rolls around, the page has already rendered improperly because the session > > variable hasn't been set. Has anyone else encountered this or have any > > suggestions? This behavior was not present in beta 2 which the > > application > > was originally built in. > > > Hello Chris,
I think this is possibly an page specific or environment specific issue. I've just created a simple page which use client-script callback to update some sessionState value. I could correctly read the and display the updated session in the postback after the clientscript call. Would you provide the detailed page code logic on how you update the session state in callback function and how to read them in sequential postback? Also, you can tried the same code logic on some other simplfied page or other server machine to see whether the same problem remains. Here is my test code: =============================== public partial class javascript_ScriptCallBackPage : System.Web.UI.Page, ICallbackEventHandler { protected void Page_Load(object sender, EventArgs e) { ClientScriptManager cm = Page.ClientScript; String cbReference = cm.GetCallbackEventReference(this, "arg", "ReceiveServerData", "ctx"); String callbackScript = "function CallServer(arg, ctx) {" + cbReference + "; }"; cm.RegisterClientScriptBlock(this.GetType(), "CallServer", callbackScript, true); } #region ICallbackEventHandler Members public string GetCallbackResult() { return Session["Time"].ToString(); } public void RaiseCallbackEvent(string eventArgument) { DateTime time = DateTime.Now; Session["Time"] = DateTime.Now.ToLongTimeString(); } #endregion protected void btnDisplaySession_Click(object sender, EventArgs e) { Response.Write("<br/>Time: " + Session["Time"]); } } ================================= Please feel free to let me know if there is anything I missed or any other finding you've got. Sincerely, Steven Cheng Microsoft MSDN Online Support Lead ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. Note: The MSDN Managed Newsgroup support offering is for non-urgent issues where an initial response from the community or a Microsoft Support Engineer within 1 business day is acceptable. Please note that each follow up response may take approximately 2 business days as the support professional working with you may need further investigation to reach the most efficient resolution. The offering is not appropriate for situations that require urgent, real-time or phone-based interactions or complex project analysis and dump analysis issues. Issues of this nature are best handled working with a dedicated Microsoft Support Engineer by contacting Microsoft Customer Support Services (CSS) at http://msdn.microsoft.com/subscriptions/support/default.aspx. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. Steven, the difference between my code and your sample is that I am trying to
access the session value earlier in the page lifecycle. The page I have is very complex. Here is the basic flow. I set a session vairable from the client call back like so public void RaiseCallbackEvent(string eventArgument) { Session["selectedIndex"] = eventArgument; } That session value is then used to intiliaze an object datasource on a custom control that sits on that page. This occurs on the object datasource's load event. The problem is that in Firefox the session variable is getting set before this, but in IE it's being set afterward. However, if I run everything in the debugger, it behaves as expected. I do realize that this is a weird way of passing data around, but it was the only option at the time it was written. Show quote "Steven Cheng[MSFT]" wrote: > Hello Chris, > > I think this is possibly an page specific or environment specific issue. > I've just created a simple page which use client-script callback to update > some sessionState value. I could correctly read the and display the updated > session in the postback after the clientscript call. > > Would you provide the detailed page code logic on how you update the > session state in callback function and how to read them in sequential > postback? > > Also, you can tried the same code logic on some other simplfied page or > other server machine to see whether the same problem remains. Here is my > test code: > > =============================== > public partial class javascript_ScriptCallBackPage : System.Web.UI.Page, > ICallbackEventHandler > { > protected void Page_Load(object sender, EventArgs e) > { > ClientScriptManager cm = Page.ClientScript; > String cbReference = cm.GetCallbackEventReference(this, "arg", > "ReceiveServerData", "ctx"); > > > String callbackScript = "function CallServer(arg, ctx) {" + > cbReference + "; }"; > > cm.RegisterClientScriptBlock(this.GetType(), > "CallServer", callbackScript, true); > } > > #region ICallbackEventHandler Members > > public string GetCallbackResult() > { > return Session["Time"].ToString(); > } > > public void RaiseCallbackEvent(string eventArgument) > { > DateTime time = DateTime.Now; > > Session["Time"] = DateTime.Now.ToLongTimeString(); > > > } > > #endregion > protected void btnDisplaySession_Click(object sender, EventArgs e) > { > Response.Write("<br/>Time: " + Session["Time"]); > } > } > ================================= > > Please feel free to let me know if there is anything I missed or any other > finding you've got. > > Sincerely, > > Steven Cheng > > Microsoft MSDN Online Support Lead > > > > ================================================== > > Get notification to my posts through email? Please refer to > http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif > ications. > > > > Note: The MSDN Managed Newsgroup support offering is for non-urgent issues > where an initial response from the community or a Microsoft Support > Engineer within 1 business day is acceptable. Please note that each follow > up response may take approximately 2 business days as the support > professional working with you may need further investigation to reach the > most efficient resolution. The offering is not appropriate for situations > that require urgent, real-time or phone-based interactions or complex > project analysis and dump analysis issues. Issues of this nature are best > handled working with a dedicated Microsoft Support Engineer by contacting > Microsoft Customer Support Services (CSS) at > http://msdn.microsoft.com/subscriptions/support/default.aspx. > > ================================================== > > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > Hello Chris,
I've just performed some further test and did find the problem though the behavior is abit different. Here is my test: ** In client-side code, after I call the script callback function, I submit the form (through document.form1.submit()) ================== function testcallback() { var ret = CallServer(document.getElementById("txtInput").value, 'input'); document.form1.submit(); } ========================= Then,l in the submit postback, the ObjectDataSouce.Load event seems always get the SessionState in the last request(not the one set in the previous script callback). Are you doing the similar thing and get the similar behvior as mine? BTW, in my test machine, it behave same no matter I use IEor firefox. It seems the cause of the problem is the script callback function will send the background httprequest asynchronously, and if we directly peform postback(like submit the form ) after the script callback function, it will result such problem. So far I have tried two means which can workaround this problem: 1) use window.setTimeout to add a delay between the script callback call and other postback function call e.g. =================== function testcallback() { var ret = CallServer(document.getElementById("txtInput").value, 'input'); window.setTimeout("document.form1.submit()", 1000); } ===================== 2) other means is to add our own postbcack call in the script callback's receive callback function, this receive callback is executed when the background httrequest has finished and I think this is a good place to put seqentual script code. e.g.: function ReceiveServerData(arg, context) { alert("arg: " + arg + ", ctx: " + context); //do our own postback here document.form1.submit(); } This works well on my side(in both firefox and IE6). Hope this helps. Sincerely, Steven Cheng Microsoft MSDN Online Support Lead ================================================== Get notification to my posts through email? Please refer to http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif ications. Note: The MSDN Managed Newsgroup support offering is for non-urgent issues where an initial response from the community or a Microsoft Support Engineer within 1 business day is acceptable. Please note that each follow up response may take approximately 2 business days as the support professional working with you may need further investigation to reach the most efficient resolution. The offering is not appropriate for situations that require urgent, real-time or phone-based interactions or complex project analysis and dump analysis issues. Issues of this nature are best handled working with a dedicated Microsoft Support Engineer by contacting Microsoft Customer Support Services (CSS) at http://msdn.microsoft.com/subscriptions/support/default.aspx. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. Steven, thanks for your help. Let me try that and I'll get back to you.
Show quote "Steven Cheng[MSFT]" wrote: > Hello Chris, > > I've just performed some further test and did find the problem though the > behavior is abit different. Here is my test: > > ** In client-side code, after I call the script callback function, I submit > the form (through document.form1.submit()) > > ================== > function testcallback() > { > var ret = CallServer(document.getElementById("txtInput").value, > 'input'); > > document.form1.submit(); > > } > ========================= > > > Then,l in the submit postback, the ObjectDataSouce.Load event seems always > get the SessionState in the last request(not the one set in the previous > script callback). Are you doing the similar thing and get the similar > behvior as mine? BTW, in my test machine, it behave same no matter I > use IEor firefox. > > It seems the cause of the problem is the script callback function will send > the background httprequest asynchronously, and if we directly peform > postback(like submit the form ) after the script callback function, it will > result such problem. > > So far I have tried two means which can workaround this problem: > > 1) use window.setTimeout to add a delay between the script callback call > and other postback function call e.g. > =================== > function testcallback() > { > var ret = CallServer(document.getElementById("txtInput").value, > 'input'); > > window.setTimeout("document.form1.submit()", 1000); > > } > ===================== > > > 2) other means is to add our own postbcack call in the script callback's > receive callback function, this receive callback is executed when the > background httrequest has finished and I think this is a good place to put > seqentual script code. e.g.: > > function ReceiveServerData(arg, context) > { > alert("arg: " + arg + ", ctx: " + context); > > //do our own postback here > document.form1.submit(); > } > > > This works well on my side(in both firefox and IE6). > > Hope this helps. > > Sincerely, > > Steven Cheng > > Microsoft MSDN Online Support Lead > > > > ================================================== > > Get notification to my posts through email? Please refer to > http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif > ications. > > > > Note: The MSDN Managed Newsgroup support offering is for non-urgent issues > where an initial response from the community or a Microsoft Support > Engineer within 1 business day is acceptable. Please note that each follow > up response may take approximately 2 business days as the support > professional working with you may need further investigation to reach the > most efficient resolution. The offering is not appropriate for situations > that require urgent, real-time or phone-based interactions or complex > project analysis and dump analysis issues. Issues of this nature are best > handled working with a dedicated Microsoft Support Engineer by contacting > Microsoft Customer Support Services (CSS) at > http://msdn.microsoft.com/subscriptions/support/default.aspx. > > ================================================== > > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > > > > Unfortunately neither of those solutions work. I have an alert() in my
callback return method and that isn't even showing, so I don't know if the callback return method is getting run before the page posts. It still works perfectly in FF and not IE Show quote "Steven Cheng[MSFT]" wrote: > Hello Chris, > > I've just performed some further test and did find the problem though the > behavior is abit different. Here is my test: > > ** In client-side code, after I call the script callback function, I submit > the form (through document.form1.submit()) > > ================== > function testcallback() > { > var ret = CallServer(document.getElementById("txtInput").value, > 'input'); > > document.form1.submit(); > > } > ========================= > > > Then,l in the submit postback, the ObjectDataSouce.Load event seems always > get the SessionState in the last request(not the one set in the previous > script callback). Are you doing the similar thing and get the similar > behvior as mine? BTW, in my test machine, it behave same no matter I > use IEor firefox. > > It seems the cause of the problem is the script callback function will send > the background httprequest asynchronously, and if we directly peform > postback(like submit the form ) after the script callback function, it will > result such problem. > > So far I have tried two means which can workaround this problem: > > 1) use window.setTimeout to add a delay between the script callback call > and other postback function call e.g. > =================== > function testcallback() > { > var ret = CallServer(document.getElementById("txtInput").value, > 'input'); > > window.setTimeout("document.form1.submit()", 1000); > > } > ===================== > > > 2) other means is to add our own postbcack call in the script callback's > receive callback function, this receive callback is executed when the > background httrequest has finished and I think this is a good place to put > seqentual script code. e.g.: > > function ReceiveServerData(arg, context) > { > alert("arg: " + arg + ", ctx: " + context); > > //do our own postback here > document.form1.submit(); > } > > > This works well on my side(in both firefox and IE6). > > Hope this helps. > > Sincerely, > > Steven Cheng > > Microsoft MSDN Online Support Lead > > > > ================================================== > > Get notification to my posts through email? Please refer to > http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif > ications. > > > > Note: The MSDN Managed Newsgroup support offering is for non-urgent issues > where an initial response from the community or a Microsoft Support > Engineer within 1 business day is acceptable. Please note that each follow > up response may take approximately 2 business days as the support > professional working with you may need further investigation to reach the > most efficient resolution. The offering is not appropriate for situations > that require urgent, real-time or phone-based interactions or complex > project analysis and dump analysis issues. Issues of this nature are best > handled working with a dedicated Microsoft Support Engineer by contacting > Microsoft Customer Support Services (CSS) at > http://msdn.microsoft.com/subscriptions/support/default.aspx. > > ================================================== > > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > > > >  |
|||||||||||||||||||||||
Other interesting topics