PageMethod vs WebSerivce/ServiceMethod

I've seen people say that we shouldn't use PageMethods and should stick with using web services as is currently written, however, I've not seen a reason why. My situation right now is that I want to combine the HoverMenuExtender and DynamicPopulateExtender to display a preview of an item for my gridview. However, my site uses forms authentication, and if I try to pull the html (screen grab) from the page, I just get the forms login page. So I'm curious as to why I shouldn't use a page method which wouldn't have the authentication problem. We already have a webservice running, and I'd rather use that webservice, but since it seems like I can't - I'd rather use a page method then start another webservice.Surely someone has an opinion
Surely someone has an opinion
Performance would come to mind. A page method requires an (almost) complete run through the page life cycle. Only the render phase is scipt.
Hi,

a page method doesn't require a full run through the page lifecycle. For this reason it is the preferred alternative to a partial postback, where the page goes through all its lifecycle.

Also, in a partial postback, even if only the html for the controls to update is sent in the response, all the web controls are actually rendering their content (but they do it writing into a NullTextWriter).
PageMethod:
I and the IL code disagree. The ScriptModule Registers the PageServiceHandler which in turn sets a RenderMethodDelegate. Therefor, the page runs up unitl the Render method like it would normally. -> Less performance than a WebService call.

Thanks for the heads up on the UpdatePanel. Checked out the IL Code and there it is (the RenderMethodDelegate) in hte ScriptManager.
Hi,

apologies for the confusion I made in my last post, you're perfectly right.

However, my opinion is that the choice between a page method and a web service should be driven by the particular scenario (the data to expose, the need for the elaboration to access the controls on the page) and not by performance.

PageMethods quirk

So here's what I found while using PageMethods in Beta 2

A server side method needs the attribute [System.Web.Services.WebMethod]A server side method should be static or else you'll get a PageMethods is undefined errorA server side method should NOT be defined in code behind but should be in the ASPX page in <script runat="server"> tag.Here's the quirk. A server side method CANNOT have two parameters with names that differ only in the case of their letters. eg. someParam and SomeParam, even if they are of different types, e.g. string and int This will result in a Sys.ArgumentTypeException with the message Object of type Number cannot be converted to type Function. Parameter name OnSuccess.

<script runat="server"> [System.Web.Services.WebMethod] public static string SomeMethod(string someParam, int SomeParam) { return "Hello " + someParam + " you are " + SomeParam.ToString() + " years old"; } </script>

<script type="text/javascript" language="javascript"> function CallMethod() { var age = 28; PageMethods.SomeMethod('MyName',age, OnCallResponse); } function OnCallResponse(arg) { alert(arg); } </script>

Change the SomeParam to age and it will work.

So my question is : Is this a bug, quirk or by design? If a bug or quirk will it be fixed? Sure one NEVER names two parameters the same with just a change in the case but then again, NEVER say NEVER.

Thanks

I SO MUCH SUPPORT your finding #3. It's so stupid that the server side code won't work in code-behind but inline code would work. What the heck?

To any MSFT moderator:

Is there any workaround for #3? This is driving me crazy.

Weird, but I just tried to create a page just like yours and it works even if the static method is in the code behind...

This is the class:

public partialclass _Default : System.Web.UI.Page { [WebMethod]public static string GetServerDate() {return DateTime.Now.ToString(); }}

And this is the ASPX:

<%@. Page Language="C#" AutoEventWireup="true" CodeFile="~/Default.aspx.cs" Inherits="_Default" %><%@. Importnamespace="System.Web.Services"%>"-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"><html xmlns="http://www.w3.org/1999/xhtml">Untitled Page"server"> "form1" runat="server" method="post"> "ScriptManager1" runat="server" />
 "button"value="get date" onclick="GetDate();" id="Button1" />
"date" />
 "text/javascript">function GetDate(){ var div = document.getElementById("date"); PageMethods.GetServerDate(function (result) { div.innerText = result; });}

Sorry about my last post which is unreadable...

Reposted:

Weird, but I just tried to create a page just like yours and it works even if the static method is in the code behind...

This is the class:

public partialclass _Default : System.Web.UI.Page
{
 [WebMethod]
public static string GetServerDate()
 {
return DateTime.Now.ToString();
 }
}

And this is the ASPX:

<%@. Page Language="C#" AutoEventWireup="true" CodeFile="~/Default.aspx.cs" Inherits="_Default" %><%@. Import namespace="System.Web.Services"%><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"> <title>Untitled Page</title></head><body> <form id="form1" runat="server" method="post"> <asp:ScriptManager ID="ScriptManager1" runat="server" /> <div> <input type="button" value="get date" onclick="GetDate();" id="Button1" /> <div id="date" /> </div> </form> </body></html><script type="text/javascript">function GetDate(){ var div = document.getElementById("date"); PageMethods.GetServerDate(function (result) { div.innerText = result; });}</script>

This looks a bug, thanks for reporting this issue, and it will be fixed in a future build.
-Hao

Hi,

that is not a bug. Remember that vbscript is case unsensitive.

Hi,

I tried the approach of using static methods for PageMethods in AJAX v1.0 Beta 2, but it is not working. The only change that happened is that the error message has changed from "PageMethods is undefined" to "PageMethods is null or not a object.

PLEASE HELP !!!!

Advance,

Where the heck is "vbscript" in whole picture? We are trying to access a WebMethod from Javascript using MS Ajax Beta 2 in the code-behind file.

I was hoping this would have been corrected in Beta 2. I guess I'll keep using the ATLAS CTP until this is resolved. Oh well, maybe in build 3??

hello.,

this is correct. the problem is related with the EnsureParameters of the WebServiceMethodData class. I don't know why, but it's "eating parameters" when they have the same name and differ only in case. here's the "bad" code:

privatevoidEnsureParameters()
{
if (this._parameterData ==null)
 {
lock (this)
 {
Dictionary<string,WebServiceParameterData>dictionary1 =newDictionary<string,WebServiceParameterData>(StringComparer.OrdinalIgnoreCase);
intnum1 =0;
foreach (ParameterInfoinfo1inthis._methodInfo.GetParameters())
 {
dictionary1[info1.Name] =newWebServiceParameterData(info1,num1);
num1++;
 }
this._parameterData =dictionary1;
 }
 }
}

I've tried reproducing this with a simple method and i get the 2 parameters and if i add them to a dictionary, i get 2 entries. this is not happening here (yes, i've used reeflection to reproduce what's going on and i can say that the dic only has one parameter.

if anyone have an idea on why is that, please,share with us!

thanks. 

hi.

dom't you hate it when you spend 1 hour looking at code and writing reflection just to see that the damn thing is right in front of you?:

newDictionary<string,WebServiceParameterData>(StringComparer.OrdinalIgnoreCase);

thanks Garbin!

Yeah, there are two places in the code that are using OrdinalIgnoreCase comparers which is what's causing the problem, removing the IgnoreCase for both dictionaries fixes the problem.

Hope that helps,
-Hao

hello.

does that mena that it'll be removed in the next release?

Yes I've already fixed it in the codebase.

Hope that helps,
-Hao