i have been reading a little about REST services and i would love to know more.
I wonder if anyone can confirm, currently we have a wcf web service (ending in .svc) and we have many clients accessing (i.e. form linux, max and PC) ...
if i was to change my server to use REST then would the clients break?
If you CHANGE the service to be a RESTful format, then yes...existing clients would have to change.
If you ADD a RESTful endpoint and kept the existing endpoint as well, then no...existing clients could continue to use the old endpoint until they migrated their code to use the new RESTful endpoint.
Well, the two world are really SOAP vs. REST.
The "normal" WCF services using NetTcpBinding, basicHttpBinding, wsHttpBinding etc. are all using SOAP - your message is embededded in a SOAP envelope and sent across the wire, and the response comes back the same way. That's why you can't just point your browser to a WCF service and get data - browsers can't send and receive SOAP messages.
Advantages of SOAP: you have things like WSDL/XSD to clearly and very strictly define what your service does and what kind of data you send around.
REST is a totally different beast - no more SOAP, no more WSDL and XSD, no more creating a client that knows about the data types being shuffled back and forth - you just have URL's which represent resources, and you get back some XML - not a whole lot of system support for describing WHAT that XML will be - you'll have to hope the developer of the REST service provides some documentation about what can be retrieved, and what it looks like.
So REST is a totally different beast than SOAP, and it's implemented in WCF using the webHttpBinding.
So if you have existing "traditional" WCF service and clients, and you now switch your service to REST, then yes - 100% sure you'll break EVERY client....
Marc
Related
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]
I've been playing around with WCF and I have managed to a WCF service to generate both SOAP, POX, and JSON formats pretty easily based on this example (I added the soap config).
http://www.c-sharpcorner.com/UploadFile/ashutosh.shukla1/3040/Default.aspx
And I see that if you add a timestamp field to your data base tables you can actually have a plain old WCF service work with Linq to SQL via this-
http://jonkruger.com/blog/2008/02/10/linq-to-sql-in-disconnectedn-tier-scenarios-saving-an-object/
I'm still a little confused about WCF vs WCF Data Services vs WCF Ria Services. I guess my goal and my question is.
Is it possible to write one service with multiple endpoints that does it all...POX, JSON, Java client compatible SOAP 1.1 with https and user name/password protection, and OData secured with https possibly as well? If so that sounds amazing, as I can create a self hosted uber data provider service that offers numerous ways clients can connect and use data.
Are we there yet? If so what do I use (still confused on the differences)?
Folks,
I'm building a pretty standard workflow that I want exposed via a WCF endpoint - I'm using the "WCF Service Application" project template and I've got a .xamlx service. This is a very simple document interchange workflow service - I want consumers to POST me a blob of XML as the body of an HTTP post (with HTTP headers containing authentication tokens). In response, these consumers will get a blob of XML containing the reply. 2 goals for me using REST/POX here are the document/message-based nature of the interaction AND I want to make client development easy for non-.NET environments (especially limited environments like Silverlight and iPhone).
I don't really see how to make this possible using out of the box features (unless I'm missing something). Does anybody know how to create a RESTful (or even REST-ish, I'm not picky) endpoint for a WF4 service-hosted workflow? Any info leading in the right direction here would be great.
There is an unreleased item on CodePlex to cover this, which includes source code. Also see this SO answer which contains another idea for achieving this.
If you'd like to see the CodePlex activity released, please up-vote the UserVoice request.
Using a REST Pass-Through Service
As #Maurice mentions, you can also treat the WF service as a back-end service and expose a REST service that simply calls through to the WF service.
This method is a bit clumsy, but has the advantage that it doesn't use anything unreleased or really complicated.
If the back-end service runs on the same machine as the REST service (which is probably what you'd do), you should expose the WF service using the named pipes binding. This binding is fast, but only works when the caller and callee are on the same box.
A further thought: your REST pass-through service is blocked while the back-end service is being called. If your WF service is not very fast, you'd benefit from making your REST service asynchronous so it doesn't block a thread pool thread while the WF service is being called.
There are no out of the box activities that will allow you to use REST with WF, the Receice is pure SOAP.
You can either build a custom REST Receive activity and use that with your workflow. Depending on your needs this is going to be quite a handful to a lot of work. The easy option is use use a standard REST WCF endpoint and convert the REST data to SOAP, pass rhe request on to the workflow, and do the reverse on the result message.
I have a web service that is used by many different clients using many different languages.
I want to switch it to wcf to take advantage of the many different endpoints.
However what has been stopping me is that I am afraid that the clients will have to use a special sdk to connect (if they are using java or php or some other language) that is different then the sdk they use to connect to the existing web service.
Is this true? Or is connecting to WCF the exact same as it is for web services in other languages.
The project I am currently working on has multiple WCF configurations, some are using the default SOAP implementation, and some are using a POX (plain-old-xml) style message.
So the short answer is 'yes' you can configure WCF in such a way to work with just about anything.
However, be warned that as soon as you step outside the default little box that WCF has set up for you, it gets pretty complicated. You end up with a lot of custom message parsing and security handling if you go to a POX message format. Its easier if you stick with SOAP though.
As for needing a 'special SDK' you won't. You can communicate with WCF with simple HTTP POST messages if needed.
I have clients that are using VB.NET apps (using SOAP) and Java apps (using POX) to hit my WCF services.
A basicHttpBinding endpoint in WCF is exactly a standard SOAP endpoint, and your Java or PHP clients will not have to change in any way.
I have a Windows Service which performs a certain function, and then needs to send that information off to a webservice for processing. The webservice is hosted by a remote web application. I am trying to ascertain the best way to call the webservice(s) as each web application might be only 2.0, or 3.5 etc. In my windows service, I am defining each "client" in the app.config, e.g.
<Client WebServiceUrl="http://location.com/webservice.svc" Username="" Password="">
</Client>
The web application must implement two web services that are required for my windows service to run, however not sure the best way to implement the "rules" for the web application.
EDIT:
I'll try and rephrase..
The Windows Service runs every 30 seconds and obtains a list of information. The service supports multiple "clients" as shown above. When each client process is run, the data is collected and is then needed to be sent to the supporting web application.
The windows service does not know what to do with the data, it is just sending it. Each web application for a client would be in different locations, and could possibly be built in 2.0, 3.5, PHP, etc. All the windows service cares about, is that when it performs its processing for a client, it is able to send the data to the webservice location defined in the app.config of the windows service.
What I'm trying to determine is how to connect to the webservice (which I'm leaning towards WCF, however Basic or WS not sure), and what rules need to be defined for the web application in how to build the response.
If the Windows service is to support php applications etc, WSHttpBinding would not be an option, which would mean BasicHttpBinding would then work. The other thing to decide is whether or not to utilise a RESTful service or SOAP service.
Hope this makes more sense.
I'm not really clear on what you are doing.
It seems like you have 3 things: A Windows Service, and then a web service, hosted in a web app.
I think your question is, what to use, REST, ASMX, WSE or WCF, when interconnecting the Windows Service app with the remote web service.
ASMX, WSE and WCF are alternative programming models for the web service. REST is not a programming model. It is not like the other three.
ASMX and WSE will require that you use Web services and SOAP.
WCF can allow you to use Web services and SOAP, REST (XML or JSON) over HTTP, or a binary format over TCP, among other options.
Because it is flexible and current technology, I'd recommend WCF. ASMX is now termed "legacy technology" by Microsoft. Doesn't mean it won't work, but it will not get updates. (Much like WinForms versus WPF). WSE is no longer in mainstream support, as far as I know. For these reasons, I wouldn't recommend starting a new project on WSE, nor on ASMX.
WCF is more general than ASMX and can seem more complicated, for that reason. But once you make some choices and zero in on what you want (for example choose HTTP and REST, or choose binary and TCP), it's more powerful. WCF can be used as the programming model on both the client or sender (in your case, the Windows Service, I guess) and/or on the server (the web service hosted in the web app).
Using WCF on the client side does not imply you must use it on the server side, and vice versa. On the other hand, if you control the source code on both ends, I would recommend using WCF on both sides.
As for "how to implement the rules for the web app" - I don't understand what you are asking there. Maybe if you are more specific on the question there, someone will be able to help out.
Update: Based on your additional explanation, I'm going to suggest you look at the REST stuff in WCF for .NET 3.5. In PHP it's very easy to implement a REST-style service, and with WCF, the same is true for .NET. Now in your case the Windows service is the client and it is sending out a request, an update request, to various servers that reside on your customers' networks. According to REST principles, I'd make those outbound requests PUTs or POSTs, depending on the semantics of the call.
Then you could ship some example service code to your (uppercase) Clients, to get them started on building what they need to receive your outbound PUT/POST messages.
Security is a concern though. You didn't mention it at all, which is surprising. Security is not one of those things best deferred, so that you "add it on later". You should think about it early - it may affect the protocol choices you make. For example, if you need to mutually authenticate the clients and servers (the latter at your "uppercase" Clients' networks), then you may want to go with SOAP, which gives you good options on the protocol side for security. Secure Web services extensions (WS-Sec, etc) are well supported in WCF, but not sure about the status of this capability in PHP.