server_wcf.html

---
layout: default
title: enable cross-origin resource sharing
---

<div class="container">
    <section>
        <h1>CORS on WCF</h1>
        <p>
            For WCF service you have to develop new behavior and include it in the endpoint configuration:
        </p>
        <h5>Create Message Inspector</h5>
        <pre class="code">
             public class CustomHeaderMessageInspector : IDispatchMessageInspector
            {
                Dictionary&lt;string, string&gt; requiredHeaders;
                public CustomHeaderMessageInspector (Dictionary&lt;string, string&gt; headers)
                {
                    requiredHeaders = headers ?? new Dictionary&lt;string, string&gt;();
                }

                public object AfterReceiveRequest(ref System.ServiceModel.Channels.Message request, System.ServiceModel.IClientChannel channel, System.ServiceModel.InstanceContext instanceContext)
                {
                    return null;
                }

                public void BeforeSendReply(ref System.ServiceModel.Channels.Message reply, object correlationState)
                {
                    var httpHeader = reply.Properties["httpResponse"] as HttpResponseMessageProperty;
                    foreach (var item in requiredHeaders)
                    {
                        httpHeader.Headers.Add(item.Key, item.Value);
                    }           
                }
            }
        </pre>
        <h5>Create Endpoint Behavior and use Message Inspector to add headers</h5>
        <pre class="code">
             public class EnableCrossOriginResourceSharingBehavior : BehaviorExtensionElement, IEndpointBehavior
            {
                public void AddBindingParameters(ServiceEndpoint endpoint, System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
                {
           
                }

                public void ApplyClientBehavior(ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
                {
            
                }

                public void ApplyDispatchBehavior(ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.EndpointDispatcher endpointDispatcher)
                {
                    var requiredHeaders = new Dictionary&lt;string, string&gt;();

                    requiredHeaders.Add("Access-Control-Allow-Origin", "*");
                    requiredHeaders.Add("Access-Control-Request-Method", "POST,GET,PUT,DELETE,OPTIONS");
                    requiredHeaders.Add("Access-Control-Allow-Headers", "X-Requested-With,Content-Type");

                    endpointDispatcher.DispatchRuntime.MessageInspectors.Add(new CustomHeaderMessageInspector(requiredHeaders));
                }

                public void Validate(ServiceEndpoint endpoint)
                {
            
                }

                public override Type BehaviorType
                {
                    get { return typeof(EnableCrossOriginResourceSharingBehavior); }
                }

                protected override object CreateBehavior()
                {
                    return new EnableCrossOriginResourceSharingBehavior();
                }
            }
        </pre>
        <h5>Register new behavior in web.config</h5>
        <pre class="code">
            &lt;extensions&gt;
              &lt;behaviorExtensions&gt;        
                &lt;add name=&quot;crossOriginResourceSharingBehavior&quot; type=&quot;Services.Behaviours.EnableCrossOriginResourceSharingBehavior, Services, Version=1.0.0.0, Culture=neutral&quot; /&gt;        
              &lt;/behaviorExtensions&gt;      
            &lt;/extensions&gt;
        </pre>
        <h5>Add new behavior to endpoint behavior configuration</h5>
        <pre class="code">
            &lt;endpointBehaviors&gt;      
            &lt;behavior name=&quot;jsonBehavior&quot;&gt;
                &lt;webHttp /&gt;
                &lt;crossOriginResourceSharingBehavior /&gt;
            &lt;/behavior&gt;
            &lt;/endpointBehaviors&gt;
        </pre>
        <h5>Configure endpoint</h5>
        <pre class="code">
            &lt;endpoint address=&quot;api&quot; binding=&quot;webHttpBinding&quot; behaviorConfiguration=&quot;jsonBehavior&quot; contract=&quot;Service.IServiceContract&quot; /&gt;
        </pre>
    </section>
</div>