If I create a WCF service can it be used by any other system (legacy etc.) that can make use of HTTP GET and POST?
I would like to open up our system with WCF.
Of course yes. WCF provides interoperable bindings like BasicHttpBinding, wsHttpBinding. They can be consumed from other platforms.
have a look at: http://msdn.microsoft.com/en-us/library/ms730017.aspx
Related
I have created a WCF service and hosted it through self hosting. This service doesn't have any metada published.
First Question
Can I consume it through Visual Studio, Add Service Reference? Hopefully not.
Can I consume it by creating manual proxy, i.e. ChannelFactory<ServiceContract>....?Hopefully yes.
Now in the second scenario, the client must be .Net, right?
So it implies that, to consume a wcf service on a non-.net platform, we have to expose its metadata?
Can't a WCF service without metadata, consume by Ajax client, or say Java client??
There are 3 options to consume a WCF Service:
If the service exposes a WSDL use "add service reference" from VS (or an equivalent from another platform). Note that if you do not want to expose the WSDL you could expose it just temporarly, save the WSDL in a file, and then send it to user in any platform to generate proxy from it. You can turn off the WSDL immediately after you save it. Also note that even if the WSDL is not exposed still you need to protect the web service from unauthorized access.
If this is a .Net client it can compile with the same Service Contract assembly and use ChannelFactory etc.
Any platform can send raw soap message (e.g. XML) to the service. Of course they need to know what is the right format. A WSDL can help but even without it if they have a working sample they can imitate it.
WCF provides REST (Representational State Transfer) support to consume it by non .NET client like JavaScript (AJAX), java, Objective C, web browser, etc...
Basically WCF REST is exposes methods and transferring data over the HTTP protocol and it supports all HTTP operations (GET, POST, PUT, and DELETE). This feature is making it platform independent as well as it doesn’t require metadata exposed.
Please refere below links to get more about WCF REST:
An Introduction To RESTful Services With WCF
WCF REST Programming Model Overview
WCF Rest vs. WCF SOAP
Create RESTful WCF Service API: Step By Step Guide
What is the relationship between WCF and REST&SOAP? Is WCF based on one of those technologies (REST or SOAP) or it is a separate technology?
WCF is a messaging framework for building distributed systems. Distributed systems is mostly just another word for web services.
What this means is that you can write methods in C# (or any of the .NET languages) and then apply a bunch of configurations to the code that make your code accessible to others and turn your code into a web service.
Those "bunch of configurations" are WCF. WCF allows you to expose your methods to other computers or applications using REST if you set up the WCF configurations around your C# code to expose it as a RESTful service. Or, you can easily take the same C# methods and make them available via the SOAP protocol.
If you have a method called "GetData()", you can set up the WCF configuration to make that method available in a service that is hosted in IIS. When someone calls that service, they can send an HTTP GET request to http://www.yourdomain.com/SomeService/GetData, and the GetData method will receive the message and send back a response. When you make a GET request over HTTP, you're using the REST. REST is pretty much tied to HTTP as the transport protocol. REST also has no standard message format. Whatever you want to send in your HTTP message, and however you want to send it is OK. You can send XML, or JSON, or just plain text. You can use POST, or GET or PUT or any of the HTTP verbs as well.
With SOAP, your messages can be sent to the service using any transport protocol -- you aren't tied to HTTP. SOAP messages are designed to be transport neutral. They are encoded in XML and the XML always has a head and a body node inside of an envelope node. There are lots of web standards around SOAP -- standards for putting security, sessions and other features into the header of the message, for example. Also, with SOAP, you get a WSDL, which I won't go into explaining here, but it makes it a LOT easier for clients to program against. Most programming languages have a method of taking a WSDL and converting it into strongly-typed methods and objects so that your service is easy to call.
REST is very popular on the internet and is as scalable as the internet (i.e. VERY scalable). SOAP is very popular in business-to-business applications.
WCF isn't automatically REST or SOAP, but you can make it that way. What you need here is a tutorial:
WCF
http://www.codeproject.com/Articles/406096/A-beginners-tutorial-for-understanding-Windows
REST
http://rest.elkstein.org/
Here's some other interesting stuff:
WCF - REST / SOAP
https://msdn.microsoft.com/en-us/library/hh323708(v=vs.100).aspx
WCF and REST
https://msdn.microsoft.com/en-us/library/ee391967.aspx
Or you can do a google/bing/metacrawler/altavista search on your own.....
From MSDN
The WCF programming model provides various capabilities, such as SOAP
services, web HTTP services, data services, rich internet application
(RIA) services, and workflow services. SOAP services support
interoperability between systems that are built with Java, other
platforms, and those that use messaging standards that are supported
by Microsoft®. SOAP services also support transports such as HTTP,
TCP, named pipes, and MSMQ. Web HTTP services and data services both
support REST. Web HTTP services enable you to control the service
location, request and response, formats, and protocols. Data services
enable you to expose data models, and data-driven logic as services.
WCF also includes two programming models: The service model and the
channel model. The service model provides a framework for defining
data contracts, service contracts and service behaviors. The channel
model supports specifying formats, transports, and protocols.
Both SOAP and REST services can provide functionality to web
applications, and both can be used to exchange information in the
web's distributed environment. Each one has its own advantages, and
limitations.
Although, this question has got several good answers, just putting in my 2-cents, in an attempt for newbies to WCF vs SOAP vs REST-full services, to make it a bit easier for them to understand.
We get confusions, whether WCF supports both REST and SOAP ? And, normally, we just see generic definitions about SOAP and REST. So , we need something from Microsoft to make us feel the truth : ) So here's a screenshot from Microsoft MSDN :
So, yes, WCF supports both .
In context with OP:
SOAP services: in WCF programming model support interoperability between systems that are built with Java, other
platforms, and those that use messaging standards that are supported
by Microsoft®. These also support transports such as HTTP,
TCP, named pipes, and MSMQ.
Web HTTP services : in WCF programming model supports REST. [Source: MSDN]
Could you please tell what is the difference between a WCF client and a non-WCF client?
When I generate proxy of a WCF service using svcutil and put that in client, what is created - wcf client or non-wcf client?
When should I use WCF client and non-WCF Client?
If you have a WCF service, its services are available to potentially several types of clients - both .NET applications using WCF themselves, or other apps.
Basically, any WCF binding that start with net.... is a .NET specific binding - only other .NET apps with WCF can connect to those services and call their methods.
The bindings with basic.... or ws...... typically are interoperable, e.g. using only industry standards like SOAP and WS-* standards - those can be called from Java, Ruby, PHP - you name it. Any language/system with a SOAP stack can call such a service (provided you get the configuration right on both ends)
The webHttpBinding is another special case - it's exposing it's services over REST - which means anything with a HTTP stack (pretty much every computer system and more and more phones and devices, too) can call its methods.
As long as you are programming your stuff in .NET, always use the WCF client - it's the easiest and the best if it's available. If you need to call your WCF service from a PHP client, of course, then you have to use PHP technology and something that's compatible between the two worlds....
I'm looking to understand when to use a WCF services instead of just using webclient or httpwebrequest. I guess I'm also looking to understand the difference between the design patterns that would be appropriate for both.
Are you talking about when to create a WCF service yourself (over web service), or when to consume an existing web service using WCF instead of .NET 2.0 ASMX clients?
As for creating a WCF service yourself:
Gives you a lot more options in terms of hosting (in an app, Windows Service, IIS, WAS)
Gives you a lot more security options
Gives you a lot more protocol options (besides just HTTP, you can also use WS-*, TCP, Named Pipes, MSMQ and more)
Allows you to write your service once, and expose it on multiple end-points with different protocols at the same time
As for using WCF to talk to an existing HTTP (ASMX) web service - I don't see a whole lot of massive benefits, except WCF uses more configuration over code, and it can be good to standardize on one way of doing things, if you already use other WCF services, anyway.
Marc
I'm currently using WCF for most of the things that I would use WebClient or HttpWebRequest/HttpWebResponse in the past. While there definitely is overhead for learing how to make calls to web methods using WCF, the extensibility of WCF and the abstraction it provides makes it a MUCH better candidate for these types of calls.
I've already used it to make calls to Akismet and RPX pretty easily.
To get started, I'd look at the section of the MSDN documentation titled "WCF Web Programming Object Model", located at:
http://msdn.microsoft.com/en-us/library/bb412204.aspx
For my project's web services I want to support desktop clients and silverlight clients. Should I write a separate web service for each or put all the operations in one service? If I put them all in one, I have to go with basicHttpBinding. The winforms app uses wsHttpBinding now, what do I lose going with basicHttpBinding?
I very strongly recommend you read this thoroughly:
"Silverlight and WCF Feature Comparison"
http://msdn.microsoft.com/en-us/library/cc896571(VS.95).aspx
There are quite a few gotchas when developing a web service for silverlight usage, especially if you already have a wsHttpBinding solution. Good luck!
EDIT: also I found this article useful:
WCF : BasicHttpBinding compared to WSHttpBinding at SOAP packet level
http://geekswithblogs.net/claeyskurt/archive/2008/04/22/121508.aspx
Use one web service with two endpoints, that would allow you to support basicHttpBinding as well as wsHttpBinding.
The difference between the two bindings is that basic is Soap 1.1 whereas ws is Soap 1.2 and WS-Addressing Specifications, in addition wsHttpBinding offers more security options