Modeling State, Ignoring Transitions - Stu says stuff. Updated: Instead of reading my specific nits here, you can see a brief summary of my suggested guideline to designing a cloud interface. Ian Foster, Savas Parastatidis, Paul Watson, and Mark Mckeown have an article in the latest Communications of the ACM comparing WS-ResourceFramework (WS-RF), WS-Transfer (W-T), RESTful HTTP, and "no convention" as approaches to modeling state. This article was particularly timely, as it is very similar in approach to my "Managing Data in an SOA" talk at Jazoon 2008.
(A better formatted PDF copy of that presentation is available here.) Jazoon is primarily a Java conference, so I got the impression that about less than half of the room had even heard of the Web Services specifications I was talking about, let alone the tension among them, due to how much they overlap. Roy was in the crowd, offering the one audience comment at the end: "Given all of this, which approach would you recommend, or are you using, for your own work?
". RESTful HTTP in practice. This article gives a short overview about the basics of RESTful HTTP and discusses typical issues that developers face when they design RESTful HTTP applications. It shows how to apply the REST architecture style in practice. It describes commonly used approaches to name URIs, discusses how to interact with resources through the Uniform interface, when to use PUT or POST and how to support non-CRUD operations. REST is a style, not a standard. There is neither a REST RFC, nor a REST protocol specification nor something similar. The REST architecture style has been described in the dissertation of Roy Fielding, one of the principal authors of the HTTP and URI specification. An architecture style such as REST defines a set of high-level architectures decisions which is implemented by an application. Even though REST is heavily influenced by the Web-Technology, in theory the REST architecture style is not bound to HTTP. Resources Resources are the key abstractions in REST.
Representations. Best Practices for building JSON REST Web Services « Building Fe. A few of our friends have been asking us what are some of the best practices we learnt over the last two years designing and implementing RESTful Web Services as the back-end of the feedly service. Here is a quick/high level brain dump: Phase 1 – Defining a simple resource/service | Take a sample resource such as Customer Information, model it as JSON. Build a simple servlet where PUT creates a new customer, GET returns the customer information based on the customer key, DELETE deletes the customer and POST updates the customer information.
Make sure that PUT returns the right information regarding the URL of the newly created resource. In our case, we have a framework which maps JSON to our Java Model and use hibernate to persist that model in a MySQL database. Phase 2 – Implementing a client | Learn how to build a simple Javascript client which interacts with the service you built in phase one. We will try to add more as our back end evolves. Update July 8th 2009. Like this: Ryanolshanrest - Google Code. Dan Rigsby » REST Services and Metadata Endpoints in WCF. REST Services and Metadata Endpoints in WCF Posted by Dan Rigsby on May 29th, 2008 As mentioned in a previous article , there is no defined a way to get metadata about REST based services using webHttpBinding .
Since REST doesn’t use SOAP , there is no WSDL that defines the service and no built in way to generate metadata about it. REST operations return back POX or JSON or something else. You can still create a mexHttpBinding endpoint which can be used to represent the structure of the data that the REST service understands. One common tactic to give the REST service some kind of documentation, is to have a "Documentation" or "Help" method on your service that returns a an HTML page as a Stream which describes how to work with the REST service (as seen in pictureservices ).
Example Lets look at an example of the "Documentation" method on a REST service. The operation to look at is "GetDocumentation". [OperationContract] [WebGet(UriTemplate = "help" )] Stream GetDocumentation(); Demystifying The Code : REST in WCF Blog Series Index. Bill de hÓra: Patterns of Web Architecture. Eric Newcomer: "This afternoon I finally caught up up on Steve Vinoski's recent article and blog entries about the "evils" of RPC.
If you aren't already among those who have read them thoroughly, I'd encourage you to. Including the comments, it's one of the best discussions of the merits and demerits of RPC and REST that I've ever seen. The core of his argument is that the RPC abstraction is not helpful - in fact the opposite. Explicit programming is preferable when creating distributed applications. As someone in the middle of designing another RPC based system (Distributed OSGi), though, I'd like to weigh in with a few thoughts. ;-) As I've said before, the distributed OSGi design does not really represent a new distributed computing system.
The goal of distributed OSGi is to standardize how existing distributed software systems work with OSGi, extending the OSGi programming model to include remote services (today the standard only describes single JVM service invocations). Fielding Dissertation: CHAPTER 5: Representational State Transfe. [Top] [Prev] [Next] This chapter introduces and elaborates the Representational State Transfer (REST) architectural style for distributed hypermedia systems, describing the software engineering principles guiding REST and the interaction constraints chosen to retain those principles, while contrasting them to the constraints of other architectural styles. REST is a hybrid style derived from several of the network-based architectural styles described in Chapter 3 and combined with additional constraints that define a uniform connector interface.
The software architecture framework of Chapter 1 is used to define the architectural elements of REST and examine sample process, connector, and data views of prototypical architectures. 5.1 Deriving REST The design rationale behind the Web architecture can be described by an architectural style consisting of the set of constraints applied to elements within the architecture. 5.1.1 Starting with the Null Style 5.1.2 Client-Server 5.1.3 Stateless. IEEE-Convenience_Over_Correctness.pdf (application/pdf Object) Brain.Save() - WCF Web Programming Model Documentation.
Brain.Save() WCF Web Programming Model Documentation Friday, January 18 2008 - blog I've gotten a lot of requests (internally and externally) for requests for resources on how to use the new WCF Web Programming Model features in .NET 3.5. MSDN has a lot of great content on this stuff, but it's kind of sprinkled around in various places due to the way the MSDN table of contents is laid out. I figured it would be nice to have links to all of the important topics in one place, so here's the "mini-TOC" for the Web Programming Model content: Conceptual Overviews: Class Library Reference (not exhaustive): Configuration Schema: Samples: Tagged as: indigo Steve Maine Designed by Free CSS Templates.
A Brief Introduction to REST. You may or may not be aware that there is debate going on about the “right” way to implement heterogeneous application-to-application communication: While the current mainstream clearly focuses on web services based on SOAP, WSDL and the WS-* specification universe, a small, but very vocal minority claims there’s a better way: REST, short for REpresentational State Transfer. In this article, I will try to provide a pragmatic introduction to REST and RESTful HTTP application integration without digressing into this debate. I will go into more detail while explaining those aspects that, in my experience, cause the most discussion when someone is exposed to this approach for the first time.
Key REST principles Most introductions to REST start with the formal definition and background. Give every “thing” an ID I’m using the term “thing” here instead of the formally correct “resource” because this is such a simple principle that it shouldn’t be hidden behind terminology. Link things together. Addressing Doubts about REST. Invariably, learning about REST means that you’ll end up wondering just how applicable the concept really is for your specific scenario. And given that you’re probably used to entirely different architectural approaches, it’s only natural that you start doubting whether REST, or rather RESTful HTTP, really works in practice, or simply breaks down once you go beyond introductory, “Hello, World”-level stuff. In this article, I will try to address 10 of the most common doubts people have about REST when they start exploring it, especially if they have a strong background in the architectural approach behind SOAP/WSDL-based Web services. 1.
REST may be usable for CRUD, but not for “real” business logic This is the most common reaction I see among people who are skeptical about REST benefits. After all, if all you have is create/read/update/delete, how can you possibly express more complicated application semantics? 2. There are three answers to this very frequently asked question. 3. 4. 5. Dream - MindTouch OpenGarden.