I'm working on a project that will have two user interfaces. Web (asp.net MVC) and Desktop (Delphi 2010). It was requested by the customer, so we need to use Delphi.
We're thinking of architecture oriented by services, and so is WCF. To access WCF Services in Asp.Net MVC it is fine but what Need I do in Delphi? My principal doubt is, how to access a service in WCF using Delphi. Is there any way to make it easy?
Can my methods in service return IEnumerable or T[]?
Are there recommendations for this !?
Thanks!
The web services support in WCF provides many features which are not suported by Delphi - MTOM, WS-Addressing, WS-Reliable Messaging and WS-Security just to name a few. If you are designing both parts of the system (web service server and client(s)), you are in the happy situation that you can choose which features to use (as long as they are not dictated by other parties).
WCF fortunately does not 'dictate' to use SOAP. The Interoperability section in this Wikipedia article mentions for example WCF with standard XML (or RSS, or JSON). There is also a WCF binding for REST.
Planning a service oriented architecture is a tough task, so I highly recommend to read through the usual literature for this topic, and find a way to keep it as simple as possible and easy to test and evolve.
Maybe you can take a look at RemObjects SDK: it is a WCF-like solution, and you can use it for .Net, Delphi, Objective-C, PHP, C++, etc.
So you can build a server with RemObjects for .Net, for example TCP + Binary message for best performance (SOAP/XML is much slower!), and a Delphi 2010 client (even FreePascal is supported). Both sides (Delphi and .Net) are compatible with each other, even for the binary message!
My experience with RemObjects is very good: very easy to use and to build services (easier than WCF?), good support and quality etc.
One of the latest SOA framework for Delphi, is our Open Source mORMot framework.
You can use interface to define your Service contract, and access to them locally or remotely using named pipes, GDI messages, or TCP/HTTP. Your contract is defined as such on both client and server side, just like in WCF.
type
ICalculator = interface(IInvokable)
['{9A60C8ED-CEB2-4E09-87D4-4A16F496E5FE}']
function Add(n1,n2: integer): integer;
end;
It handles per-call, per-session, per-user or per-group instance live. See this sample code.
It is secure (with secure authentication at URI level), light and fast.
It uses JSON as communication (lighter than XML), and a RESTful access. It is ready to be consumed by AJAX or WCF clients (the latest after custom marshaling of the interfaces). It was optimized for speed and scalability (with advanced features like balanced custom hosting and per-interface/per-method access security).
The mORMot framework documentation has more than 800 pages, and some dedicated high-level explanation of Service Oriented Architecture design pattern in Delphi. It is integrated with a Client-Server ORM, so you have at hand all needed low-level tools to make a proper Domain-Driven application in Delphi, and other technologies.
Related
I know we are comparing 2 different technologies, but I would like to know pros and cons of both. WCF is present for almost a decade now. Didn't anything similar exist in java world until now?
At a very high level they would both appear to address the same tooling space.
However, the differences I can pick up on:
GRPC does not use SOAP to mediate between client and service over http. WCF supports SOAP.
GRPC is only concerned with RPC style communication. WCF supports and promotes REST and POX style services in addition to RPC.
GRPC provides support for multiple programming languages. WCF supports C# (and the other .net languages).
GRPC uses protobuf for on-wire serialization, WCF uses either XML/JSON or windows binary.
GRPC is open source
In short:
GRPC seems a much more focused services framework, it does one job really well and on multiple platforms.
WCF much more general purpose, but limited to .net for the time being (WCF is being ported to .net core but at time of writing only client side functionality is on .net core)
Apart from the answers mentioned, i wish to add that gRPC does not support windows/kerberos authentication, which is the defacto authentication mode in the corporate world.
For this reason, its very hard to migrate from WCF to gRPC.
As tom already mentioned:
WCF uses either XML/JSON or windows binary
while gRPC use binary, which makes messages much thinner and faster to deserialize on the client/server end-point. simply by dropping the human readability feature.
Also, please note that WCF needs extra configurations (and hassles) to comply with HTTP2 to gain its profits, e.g: shorter header and body (which means even faster transmission), more secure and reliable connection, and multiplexing (a.k.a multiple request/response in parallel), server-push and so-on ..., while gRPC has already embraced it.
I am relatively new to WCF. I am developing Web application.
I am trying to understanding "Why WCF" and read many articles .
But in many places it has been mentioned "to developed service oriented architecture ,to asynchronously send data" without any detailed explanation / any basic example.
Can somebody please let me know one simple example in layman's term ,"Why WCF" so that I can appreciate its existence.
I have had conversations with many people but none of them were able to answer this basic question.
I am also aware that ,many hundreds of applications have gone live before WCF was there...
Suppose, you do have a task to make a procedure of recieving of the coordinate point (lat,lon) and and returning the picture of the surrounding area. Or to make a language translator from voise input to text output. These jobs could uses several servers with a lot of data and could makes some huge mathimatic calculations. But you procedure should me quick, platform independend, secured, protocol-independent, consumed by different technologies (Web, Mobile, Applications). And at the same time it should be easy to consume by the end users, which do know nothing about you. As the main aim of ASP to handle web requests and generate the html responses, so the aim of WCF is to supply the end user with some useful functionality, developed by another user, remotly.
The developer creates a service (WCF) where he specifies its adress, binding and contract. Knowing these parameters other developers can consume this service. They can consume it by ASP, SilverLight, WPF, WinForms or any other technology (even none-microsoft), using SOAP protocol.
From Wikipedia:
The Windows Communication Foundation (or WCF) is an application
programming interface (API) in the .NET Framework for building
connected, service-oriented applications.
WCF is meant for designing and deploying distributed applications
under service-oriented architecture (SOA) implementation. **
Architechture
** WCF is designed using service oriented architecture principles to support distributed computing where services have remote consumers.
Clients can consume multiple services; services can be consumed by
multiple clients. Services are loosely coupled to each other. Services
typically have a WSDL interface (Web Services Description Language)
that any WCF client can use to consume the service, regardless of
which platform the service is hosted on. WCF implements many advanced
Web services (WS) standards such as WS-Addressing,
WS-ReliableMessaging and WS-Security. With the release of .NET
Framework 4.0, WCF also provides RSS Syndication Services,
WS-Discovery, routing and better support for REST services. Endpoint A
WCF client connects to a WCF service via an Endpoint. Each service
exposes its contract via one or more endpoints. An endpoint has an
address (which is a URL specifying where the endpoint can be accessed)
and binding properties that specify how the data will be transferred.
http://en.wikipedia.org/wiki/Windows_Communication_Foundation
Useful resources:
http://msdn.microsoft.com/sv-se/library/dd943056%28en-us%29.aspx
http://www.wcftutorial.net/
http://blah.winsmarts.com/2008-4-Writing_the_WCF_Hello_World_App.aspx
http://blah.winsmarts.com/2008-4-Writing_your_first_WCF_client.aspx
I would like to use a technology that is used for communication between services and several thousands of clients. I came to know of WCF and read a little about it. While it looks attractive and has no interoperability issues, i would like to know about other leading technologies which can give me the same features as WCF ? Are there any open source technologies out there ? Also, which is the most widely used technology? I just want this information before i commit myself to WCF.
EDIT: By alternative to WCF, i mean to say that i am looking for a framework that will help me to implement a webservice in linux or any other platform. For example, the wcf simplifies the process of creating a webservice by the use of hard coded .NET applications. Similarly, i need a tool in linux. I came across mono,but found out that it is not complete and not very reliable.
I also provide an Open Source WCF alternative in ServiceStack A modern, code-first, DTO-driven, WCF replacement web services framework encouraging code and remote best-practices for creating DRY, high-perfomance, scalable REST web services.
There's no XML config, or code-gen and your one clean C# web service is enabled all JSON, XML, SOAP, JSV, CSV, HTML endpoints are enabled out-of-the-box. It includes generic sync/async service clients providing a fast, typed, client/server communication gateway end-to-end.
I don't think there is any .net framework with comparable features. But the core protocols of WCF such as WSDL/SOAP are not Microsoft specific so it's not as if you're tying yourself into a particular protocol, you're just choosing an implementation.
To put it another way if you choose to migrate away from .net in the future then I would say the WCF migration would be one of the easiest parts. But if you stay with .net WCF is almost certainly going to be the best implementation available given the investment Microsoft has in it (Azure is built on WCF for example).
I am learning wcf but I have trouble understanding the benefits. Is there ever a time I would want to use traditional web services?
I read another thread with these benefits:
Opt in model for members using a certain attribute
Better security
No need to worry about binding (can't understand how this is true)
No need to worry about the xml
I read Programming WCF Services however this was an advanced book a bit like CLR via C#. I am now reading Learning WCF Services and will read Essential WCF (is recommended).
What would happen if I use a normal class to try to talk to a web/service reference? I know this sounds really naive, it's just my lack of experience in web services.
I am coding some WCF services so I am getting exposed to the specifics. They are interacting with a SOAP web service provided by my web host so I can get stats on my site. Is there anything wrong in this approach?
Thanks
WCF is a unified programming model for developing connected systems. What this means is that you use a single framework to develop service-oriented solutions. WCF allows you to keep your service implementation relatively unaware and care free of what's going on under the covers as far as how your service is consumed by clients and communication is handled. This allows you to take your service implementation and expose it in various ways by configuring it differently without touching your service implementation. This is the unified part. Without WCF, you have to get familiar with a framework specific for a particular communication technology such as ASP.NET asmx web service, .NET remoting, MSMQ etc and usually those frameworks impose on your service implementation and creep in such as using WebMethod attribute or having to derive from MarshallByRefObject object etc and you just can not take your service implementation and easily expose it over another communication stack. If I have a service that adds two numbers, why can it not be exposed over http or tcp easily without having to worry about low level details? This is the question in your post regarding binding. Binding allows you take a service and configure it so that it can be exposed over different transports and protocols using different encodings without ever touching your service implementation.
Is there ever a time I would want to use traditional web service?
Web service uses well defined, accepted, and used standards such as HTTP and SOAP. So if you want your service to be consumed by wide range of clients, then you would want to expose your service as a web service. WCF comes with pre-configured bindings out of the box that allows your service to be exposed as a web service easily: basicHttpBinding and wsHttpBinding. You may also want to consider RESTful services which is an architectural style that fits more natural with the HTTP model. WCF supports RESTful services as well
What would happen if I use a normal
class to try to talk to a web/service
reference? I know this sounds really
naive, it's just my lack of experience
in web services.
WCF service can expose the wsdl for a service just like ASP.NET asmx web service does. You can generate a client side proxy by simply adding a service reference to your client project. There is also a command line tool called svcutil that also generates the client side code that allows you to easily communicate with the service. The client side service class basically mirrors the service interface. You create an instance of the client side proxy for the service and then simply call methods on it just like any other .NET object. Under the covers, your method call will get converted to a message and sent over the wire to the server. On the server side, that message will get dispatched to the appropriate service method.
I hope this helps a bit.There are lots of online content such as videos on MSDN and channel 9 that you check out. The more you pound on it and expose yourself to it, the clearer WCF will get I am sure. Also, WCF is THE framework Microsoft recommends to develop connected system in .NET. The other technologies ASP.NET asmx, WSE, and .NET Remoting will most likely still be available going forward but may not be supported and developed further.
There are a number of existing approaches to building distributed applications. These include Web services, .NET Remoting, Message Queuing and COM Services. Windows Communication Foundation unifies these into a single framework for building and consuming services.
Here is a link from MSDN Why Use Windows Communication Foundation?
WCF is really the "new" standard and new generation of web service - and even more generally, communications - protocols and libraries for the .NET world.
Whenever you feel the need to have two systems talk to one another - think WCF. Whether that'll be behind the corporate firewall in your company LAN, whether it's across the internet, by means of a direct call or a delayed message queueing system - WCF is your answer. Mehmet has written a really nice summary of how WCF is the unification of a great many communication standards that existed in the Microsoft world before WCF.
I would think with the "Learning WCF" book, you should be a lot better off than with Programming WCF - that's quite advanced stuff already!
One of the mainstays of WCF is the architecture that you always talk to your service through a proxy - whether that service runs on the same machine using NetNamedPipe binding or halfway around the world in Down Under on a server - no difference, you always go through a proxy. That then also allows WCF to be so extensible - thanks to the proxy always being between the client (your application) and the service, it offers excellent ways of extending the behavior and the inner workings of WCF to your liking and needs.
WCF basically builds on SOAP communications - so interfacing and using existing SOAP services should be no problem at all. With the WCF REST Starter Kit and in the upcoming .NET 4.0 release cycle, WCF will also extend its reach into the REST style web communications, if that's ever going to be a requirement of yours.
All this really shows one of the biggest strenghts of WCF: it's a unified and extremely flexible and extensible communication framework, that can handle just about anything you throw at it. That alone is more than enough reason to learn WCF (which can be dauting at first, I agree!), and you won't regret the effort you put into this endeavor.
Marc
Have you a specific application you are writing for, or just getting your feet wet?
Google protocol buffers, is a very good choice of communications. John Skeet & Marc Gravell have both done C# implementations. See here
A .net desktop application will send information to a central server, there will be potentially thousands and thousands of deskop apps sending info to my server(s).
The data will be small in size.
Would .net web services be good for this scenerio or would WCF be better suited?
What are the pros/cons?
I'd go with a WCF REST-based service, because you'll be able to transmit pure data without the overhead of the SOAP header (and other envelope nonsense) that comes with the SOAP-based classic .asmx web service.
the possibilities for throttling, concurrency, etc. are far more developed within wcf.
its a little bit more work in the beginning, but i guess that it's better suited for scenarios where you need to have full control over your bindings.
WCF is a more robust approach to SOA. Microsoft is committed to making it the primary framework for building the next wave of Microsoft business applications. The functionality available already, early in its lifecycle, is superior to plain old web services. It's only going to get better. By going with WCF early, you will be able to ride the wave and take advantage of future new functionality.
In some cases depends on the type and amount of data to send.
WCF will give you more options to tweak your calls.
On the other hand, I can't think of advantages of implementing asp.net web services over WCF. In WCF you could also implement plain 'old' web services
ASMX is like remoting, it's still around because it shipped with 1.0, but you shouldn't use it anymore if you are starting a new project. WCF will give you many more features and better tooling support.