2 posts tagged “web services”

View other items tagged “web services:” Photos, Audio, Videos, Books or Links. View “web services” on Vox.

WCF Bindings

Oct 12, 2009
Post a comment

Unlike traditional web services, WCF provides many different ways to communicate with a service. These are primarily driven by the bindings as configured via the application configuration file or the web configuration file. Aside from the contracts, the binding heavily depends on what you are trying to expose and how applications will leverage it.

basicHttpBinding: use for supporting legacy clients that expect ASMX service, does not implement security by default, defaults to no credentials just like ASMX services

wsHttpBinding: WS-Reliable Messaging, WS-Security, http transport, text/xml encoding, mesage security with windows authentication by default

ws2007HttpBinding: WS-Reliable Messaging, WS-Security, http transport, text/xml encoding, binding similar to wsHttpBinding but uses OASIS, message security with windows authentication by default

netTcpBinding: optimized for cross-machine communication, generates runtime communication stack with transport security and windows authentication by default, tcp protocol, binary message encoding, must be hosted in Windows Service or IIS7 via Windows Service Activation

netNamedPipeBinding: optimized for on-machine cross process communication, generates runtime communication stack by default, WS-Reliable Messaging, transport security, named pipes for message delivery, binary message encoding, not secured by default, must be hostedin Windows Service or IIS7 via Windows Service Activation

netMsmqBinding: queued binding for cross-machine communication, used for disconnected queuing, queuing provided by MSMQ as transport, supports disconnected operations, failure isolation, load leveling, use for when client and service do not both have to be online at the same time, must be hosted in Windows Service or IIS7 via Window Service Activation

wsFederationHttpBinding: federated security, used in implementation of federation, wcf implements federation over message and mixed mode security but not over transport security, must use http protocol as transport

ws2007FederationHttpBinding: similar to wsFederationHttpBinding but uses OASIS. Commonly used in integrating with STS services.

wsDualHttpBinding: duplex service contracts over http binding through SOAP, similar to wsHttpBinding but leveraged for duplex services. Does not allow hosting in IIS5 or IIS6, host in Windows Service or IIS7.

customBinding: Describes a full binding channel with elements through protocol binding elements, message encoding binding elements, transport security binding elements and transport binding elements.

Protocol Binding Elements: Transaction Flow, Reliable Messaging, Security

Message Encoding Binding Elements: Text, MTOM, Binary

Transport Security Binding Elements: Windows, SSL

Transport Binding Elements: HTTP, HTTPS, TCP, Named Pipes, MSMQTransport, MSMQIntegration, P2P

As I mentioned each of these bindings has there own purpose. You can see that from the custom binding you can create your own configuration for how clients and services communicate with the behavior of the exposed service. You'll find that contracts and code written will, for the most part, never change when it comes to WCF. There's no reason not to create web services through WCF anymore since you can leverage any kind of communication protocol you want and throttle, secure, integrate with any system your project needs.

WCF Headstart Part 1 - Contract Construction

Apr 26, 2009
Post a comment

A lot has changed in the world of web services. This series is to get you on the right track to building incredible web services using a ridiculously easy model in the .NET 3.0 Framework.

WCF Contracts

When we build web services, we are typically working with 3 types of 'contracts'. First, we have the services we talk to. Second we have operations on all of these services to which we use the objects and messages to communicate workflow in a data-driven way. WCF creates a great analogy for each of these with contracts.

Service Contracts

Service contracts are what we use to expose an actual web service to the public. The difference in WCF is that we define those services, first, through an interface.

using System.ServiceModel;

namespace WinOrFail
{
   [ServiceContract]
   public interface IWantToWin
   {
   }
}

There are plenty of ways to define out your ServiceContract just from the attribute itself. We'll work on those later though. Adding to the contract model, are operation contracts.

Operation Contracts

The operations are pretty easy to define, just like the service contract, we place them within the interface.

using System.ServiceModel;

namespace WinOrFail
{
   [ServiceContract]
   public interface IWantToWin
   {
   [OperationContract]
   bool IsThisPossible();
   }
}

The last of the contracts are the models we define, additionally, when working with the services - we call these

Data Contracts

Data contracts have additional parameters that we can add to further define the data within it. We use the DataContract attribute to expose it for those leveraging it, and the DataMember to expose individual properties and fields. If we have additional values, such as enumerations, we can use the EnumMember for those.

using System.Runtime.Serialization;
using System.ServiceModel;

namespace WinOrFail
{
   [ServiceContract]
   public interface IWantToWin
   {
   [OperationContract]
   bool IsThisPossible();
   }

   [DataContract]
   public class Money
   {
   [DataMember]
   public double Amount { get; set; }

   [DataMember]
   public Currency Currency { get; set; }
   }

   [DataContract]
   public enum Currency
   {
   [EnumMember]
   US,
   [EnumMember]
   Euro,
   [EnumMember]
   Peso
   }
}

There you have it! The contracts used for all WCF Services :) When building WCF services it is generally best to put these in a library that you can build just for the contract definitions. It helps you separate your code concerns.

Enjoy :)