Question

Going nuts with this issue. I have a solution with 2 projects, one of them is a plain old html with jquery ajax call while the other is a WCF service. The html page will issue a ajax call to the WCF service to get a json string and use it for display purpose.

Now the issue is whenever i run in debug mode, both the html page and the WCF will be started with different port. And this has created a cross-origin issue for me when i perform testing (i.e. getting a 405 Method Not Allowed error with the calling type = OPTIONS in Firefox). I’d triple check the call method on my ajax script and the WCF service is the same (GET).

I’d search google but found that either i have to install a extension or perform some configuration on IIS, which i found cumbersome since what i’m doing is something simple. Following one example, I’d add in the following configuration in my web.config but it didn’t work:

    <system.serviceModel>
    <bindings>
      <webHttpBinding>
        <binding name="crossDomain" crossDomainScriptAccessEnabled="true" />
      </webHttpBinding>
    </bindings>
    <behaviors>
      <endpointBehaviors>
        <behavior name="MobileService.webHttpBehavior">
          <webHttp />
        </behavior>
      </endpointBehaviors>
      <serviceBehaviors>
        <behavior name="MyServiceBehavior">
          <serviceMetadata httpGetEnabled="true"  />
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
    <services>
      <service name="MobileService.SimpleMemberInfo" behaviorConfiguration="MyServiceBehavior">
        <endpoint address="" binding="webHttpBinding" contract="MobileService.IMemberInfo" bindingConfiguration="crossDomain" behaviorConfiguration="MobileService.webHttpBehavior">
        </endpoint>
      </service>
    </services>
  </system.serviceModel>
  <system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Origin" value="*" />
        <add name="Access-Control-Allow-Methods" value="GET" />
        <add name="Access-Control-Allow-Headers" value="Content-Type, Accept" />
      </customHeaders>
    </httpProtocol>
    <modules runAllManagedModulesForAllRequests="true"/>
    <directoryBrowse enabled="true"/>
    </system.webServer>

Any one has any idea to get rid of this annoying issue?

EDIT: Just to add, I’m running the debug with IIS Express that comes together with the VS Studio 2012

Add in WCF Code and Updated web.config

[ServiceContract]
public interface IMemberInfo
{
    [WebInvoke(Method = "GET",
           BodyStyle = WebMessageBodyStyle.Wrapped,
           ResponseFormat = WebMessageFormat.Json
    )]
    [OperationContract]
    string GetMemberInfoById();
    // TODO: Add your service operations here
}

My Script:

$(document).ready(function () {
    $.ajax("http://localhost:32972/SimpleMemberInfo.svc/GetMemberInfoById", {
        cache: false,
        beforeSend: function (xhr) {
            $.mobile.showPageLoadingMsg();
        },
        complete: function () {
            $.mobile.hidePageLoadingMsg();
        },
        contentType: 'application/json',
        dataType: 'json',
        type: 'GET',
        error: function () {
            alert('Something awful happened');
        },
        success: function (data) {
            var s = "";

            s += "<li>" + data + "</li>";
            $("#myList").html(s);

        }
    });
});

Answer 1

You need to use JSONP for a cross-domain call to get round the browser restrictions, and to update your web.config with crossDomainScriptAccessEnabled set to true to get round server ones. There’s a good example in the answer here: how to avoid cross domain policy in jquery ajax for consuming wcf service?

You may also have a problem with GET requests. Try the fixes outlined here:
Making a WCF Web Service work with GET requests

Altogether, you want a web.config that looks something like this:

<bindings>
  <webHttpBinding>
    <binding name="crossDomain" crossDomainScriptAccessEnabled="true" />
  </webHttpBinding>
</bindings>
<behaviors>
  <endpointBehavior>
    <behavior name="restBehavior">
      <webHttp />
    </behavior>
  </endpointBehavior>
  <serviceBehavior>         
     <behavior name="MyServiceBehavior">
        <serviceMetadata httpGetEnabled="true"  />
        <serviceDebug includeExceptionDetailInFaults="true"/>
     </behavior>
  </serviceBehavior>
</behaviors>
<services>
  <service name="..." behaviorConfiguration="MyServiceBehavior">
    <endpoint address="" binding="webHttpBinding" bindingConfiguration="crossDomain" 
              contract="..." behaviorConfigurations="restBehavior" /> 
  </service>
</services>

(Note that both the service and the endpoint have behaviours attached, allowing webHttp calls and httpGet calls respectively, and that the binding has crossDomain access explicitly enabled).

… a service method decorated like this:

[ServiceContract]
public interface IMyService
{
    [WebGet] // Required Attribute to allow GET
    [OperationContract]
    string MyMethod(string MyParam);
}

… and a client call using JSONP:

<script type="text/javascript">
$(document).ready(function() {
    var url =  "...";
    $.getJSON(url + "?callback=?", null, function(result) { // Note crucial ?callback=?
       // Process result
    });
});
</script>