WCf duplex communication with Jquery - wcf

I have a WCF service and I need to setup the service to broadcast notifications to all the connected clients. However the call to WCF is made from jquery. So I need a method to be able to call back the jquery methods from WCF for broadcast. So basically I need a way to be able to call the jquery methods from WCF.
Please let me know if its possible and also any sample to illustrate it.

Calling WCF directly from JQuery for your scenario is not a good solution.
You cannot use WCF duplex outside intranet environments because of issues such as firewalls.
You have browser clients and you need to broadcast. Try using any implementations of xmpp such as SignalR. Implementing SignalR from scratch is much easier than maintaining your current WCF code in this scenario.

Related

What is the advantage of using Web API in wpf?

I need to calling our C# Methods from another server to perform some Action. I use C# in both servers. One is our Service Application, another one is a WPF application where I consume my Service.
Prefer I use a WCF or WebAPI service for Service Application?
Most People prefer to use Web Api, but web doesn't expose metadata for creating proxy by service.
which one is simple and better choose?
You may use either WCF or WebAPI, if multiple platforms (Mobile, Web, Other Service) are going to interact with your service, then I would recommend Web API, otherwise you may use WCF. Similar discussion has already happened in another question, please refer this link, hope this will be useful
Getting a web service and using android to consume them?

Push data to client using SignalR vs WCF?

I have one WPF client-server application. Now I have scenario like client will connect to server and server will push data to client periodically. I am bit confused about what technology and way should I choose for notification to clients.
SignalR is best for web application I think and I have desktop application. With WCF service, we can implement push notification through Duplex channel and callback. So can you please guide me what are the merits and demerits in using SignalR or WCF service ?
Thanks
Below are my observations from experiences:
SignalR pros:
Easy to startup, lower learning curve. You can easily run an example found from web
Exception handling (e.g. connection drops, timeouts) is embedded inside the API
SignalR cons:
Only supporting HTTP protocol
Duplex pros:
Supports TCP in addition to HTTP. This may be a serious performance gain if you know your client types and your system is working in a closed network. Also, working over TCP adds more connection stability than HTTP
Duplex cons:
Higher learning curve - harder to startup and have a stable solution. Want to verify it? Download a duplex and a SignalR sample from the web and see how much time you will spend to successfully run each other.
You need to handle all the exceptional cases (connection drops, timeouts, etc.)
I know I am not the only one who faced serious timeout problems when you want to use the duplex service for a long time. We need to make service calls periodically to keep client connections alive.
By the way, there are APIs exist for JavaScript, Desktop and Silverlight projects to consume SignalR services.
SignalR is not just about web. SignalR server side code does not care about the technology of its clients, you just need to have implementors at the client side.
If we isolate pusing data to the client, I would strongly recommend SignalR as it's much simpler than WCF in this aspect, I had my share of problems with WCF and I guess you had some yourself.
I found a simple console/web application sample here.
In general, Duplex WCF and using Callback like here seems very messy to me, there is a lot of configuration server side and this is why I think SignalR is simpler.
In addition, you can't use duplex (AFAIK) with javascript and objective-c.
I think you already got lots of data points about each of them. But selection of SignalR will provide you added advantage over development efforts which is in most of cases major decision block while selecting a technology.
You don't need to worry about API development / testing etc. and can have focus on your own implementation of the project.
Hope it helps!
SignalR can easily be used now with multiple clients from javascript, .NET both WinForms and WPF, and can even be used with a C++ client; Using a self hosted .NET signalr server (OWIN) is really nice way to have a standalone server that pushes / receives / broadcasts to multiple clients. The only thing that may be easier is ZeroMQ using its publish subscribe methodology.
One point that nobody has raised so far:
SignalR 1.0.1 requires .NET 4 on the server and client. Depending on
the version of your client and server that you are targeting that
might be an important factor to consider.
If you just want to update periodically for new data, you might be better to just use WCF and a polling mechanism from the client side rather than using either duplex WCF or signalr.

RESTful Workflow Service Endpoints in WF4 / WCF

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.

Reverse WCF that will connect to a non .net tcpip application

I am new to .net and am trying to use c# as the basis of my .net learning. I have a project where I need a service to connect to mutliple tcpip applications that are a 3rd party application written in vb6. Someone has mentioned using WCF as the base, but i'm not sure how it would make an outbound connection (instead of receiving incoming ones) to a non .net application? Please help
With C# and WCF, you can either create:
a WCF service which will offer up some functionality that other applications can call
or:
a client that connects to some other SOAP or REST service to consume functionality.
So which one is it you're looking for??
Also: WCF is a SOAP or REST based service stack - you cannot use it to connect to low-level TCP calls (socket programming). Your "other" side must understand either SOAP (the web service protocol) or REST (the URL-based lightweight protocol). If you other sides don't speak neither SOAP nor REST, you're out of luck and can't really use WCF for that.
You'll have to deal with socket programming, WCF won't help you here.
Try reading this: http://www.codeproject.com/KB/IP/socketsincsharp.aspx

Are WCF polling duplex services usable by other clients?

I'm writing a server app with a silverlight client. At some point I'd like non-silverlight clients to be able to use my services. Right now I've written some WCF services which get polled, but I'm not happy with the responsiveness. I'm thinking of switching the code over to using Silverlight/WCF duplex polling, but if I do that, will I be stuck with Silverlight as my only client? Is it better to write my own long-polling service using normal WCF http services?
I don't see your issue there. You can just define another binding for use by other clients (like WsHttpDualBinding). The same server code will perform the exact same task regardless of the underlying binding. That's the whole point of using WCF.
You can find a AJAX sample here for using a WCF duplex service http://tomasz.janczuk.org/2009/09/scale-out-of-silverlight-http-polling.html
By other .NET client - yes. By anything else : no. WsHttpDual is definitely NOT an interoperable protocol. It also has plenty of other drawbacks and pitfalls and I'd try to stay away from it as much as possible......
Marc