Building GWT web clients [Part 4.1] – How to create an Azure RESTful web service?

Prerequisites: make sure that you have all the Azure SDK tools installed for your VS2008.

 

(1) Start by creating a new “Web Cloud Service” project in the Visual Studio. Give it a nice name.

(2) Add a new “WCF Service” to the WebRole project.

(3) Define a required contract:

The most important part here is to put attributes that will tell the WCF in what format to send/receive the message body (XML or JSON) …

[ServiceContract(Name = "service", Namespace = "http://www.igorshare.com")]
public interface IContactManagerService
{
    [OperationContract]
    [WebGet(UriTemplate = "/contacts", BodyStyle = WebMessageBodyStyle.Bare,
       ResponseFormat = WebMessageFormat.Json)]
    List<Contact> GetAllContacts();

    [OperationContract]
    [WebGet(UriTemplate = "/contacts/{filter}", BodyStyle = WebMessageBodyStyle.Bare,
       ResponseFormat = WebMessageFormat.Json)]
    List<Contact> GetContacts(string filter);
}

[DataContract]
public class Contact
{
    [DataMember]
    public string FirstName { get; set; }

    [DataMember]
    public string LastName { get; set; }

    [DataMember]
    public string Company { get; set; }
}

(4) Implement the service logic:

public class ContactManagerService : IContactManagerService
{
    private static readonly List<Contact> Contacts = new List<Contact>() { ... };

    public List<Contact> GetAllContacts()
    {
        return Contacts;
    }

    public List<Contact> GetContacts(string filter)
    {
        string f = filter.ToLower();

        var contacts = from contact in Contacts
                       where contact.FirstName.ToLower().Contains(f)
                            || contact.LastName.ToLower().Contains(f)
                            || contact.Company.ToLower().Contains(f)
                       select contact;

        return contacts.ToList();
    }
}

(5) Configure it to be exposed as a RESTful service:

To make it REALLY, REALLY simple for you, do this trick:

a) Comment out the system.serviceModel section in the Web.config file

b) Add the Factory attribute to the .svc file

<%@ ServiceHost Language="C#" Debug="true"
Service="ContactManagerCloudService_WebRole.ContactManagerService"
CodeBehind="ContactManagerService.svc.cs"
Factory="System.ServiceModel.Activation.WebServiceHostFactory" %>

(6) Build the service

 

You’re interested in 2 artifacts of the build:

1. .cscfg file – configuration for the Cloud Service deployment
2. .cspkg file – all the bits packaged (zipped)

 

At this moment you have 2 choices:

1. Run your project in the local Development Fabric (for testing and debugging), or …
2. Deploy it to the Azure Cloud (for staging or production)

 

To deploy your application to the cloud, do right-click on the CloudService project and select “Publish”.

Visual Studio will launch the Azure Service Developer Portal page. Log-in to your account, create a project and deploy your bits to the staging environment:

 

This is it!  You’re good to go.

BTW: make sure that your application works in the staging environment and then you can push it to Production by just switching it with the Staging.

 

 

Note: Check out a great explanation about the difference between the WCF REST Configuration for ASP.NET AJAX and plain REST Services by Rick Strahl.