Has anybody been able to implement HTML 5 server-sent events using WCF REST? I have attempted to do it by creating a rest service that returns a Stream and this works if I use a "hard coded" event stream (i.e. I just create a string with the event text in, turn it into a MemoryStream that is then returned by the service operation). I can then see the events happening in my test page in Chrome. However, when I try to add events to the stream asynchronously, it fails because the stream is already closed. I think I need a way of keeping the stream open permanently.
Any advice greatly appreciated!
p.s. I can't use a duplex WCF binding for this because the HTML 5 specifies non-SOAP clients (obviously).
I think you have to implement your own Binding in this case. There's no built-in Binding for comet (server-push).
There is now a WCF binding for this called NetHttpBinding:
http://msdn.microsoft.com/en-us/library/system.servicemodel.nethttpbinding.aspx
Alternatively the same thing can be achieved using SignalR, which is part of ASP.Net
http://signalr.net/
Related
I spent few days search on this case. I checked out all wcf asynchronous implementaions.
I wasn't able to find what I was looking for.
Below is scenario.
WCF is running to accept xml
WCF needs to response to user for success receiving xml and release
the request immediately
WCF then needs to do processing to save xml to database and parsing xml to
convert something else.
I don't want to use separate service to process above. I want to use one service to handle all 3 cases above.
I checked out asynchronous way of coding in WCF, but this doesn't release the request right away. What is the best practice for this? Is there any sample code I can use?
Thank you in advance.
I think you would be better suited to using a different technology. Maybe look at Windows Workflow Foundation.
You can host WCF Workflow Services the same way as you host a standard WCF service, the main difference is that you can create specific workflows that can continue after acknowledging receipt of the original message.
You do this by persisting the message and returning to the user. WF allows you to create actions that continue after sending response back to the caller.
Visual studio provides you with a design surface that allows you to drag and drop components to create custom workflows. Additionally you can also make calls to other services if required.
With .net 4.5 you can now use C#, in previous versions of WF you had to use VB.net.
You can read about it on the MSDN site here:
http://msdn.microsoft.com/en-us/vstudio/jj684582.aspx
Hope this helps
I have a simple console app that calls a WCF service over net.tcp and uploads a file (using Stream). The WCF service is self-hosted, Framework 4.0.
I am looking for a way to now add some "progress info" on the client-side. Should this be done with hand-written IASync operations, or something else altogether?
This is actually pretty easy, though the solution doesn't really have anything to do with WCF. Create a wrapper Stream subclass that you pass the actual source Stream into. In the various Read overrides, first delegate to the underlying Stream you're wrapping. Next, increment a custom property with the number of bytes read and either fire a custom event or maybe implement INotifyPropertyChanged on the custom Stream subclass. By doing this, as WCF reads from the wrapper Stream to get the bytes to send over the wire, your client will be able to observe the changes.
I need to receive XML data from HttpPost requests. Currently I use HttpWebRequest to send the request and I convert the request to xml with StreamReader and XDocument.Parse.
Are there any benefits to switching over to WCF? Thanks!
If you don't plan to dramatically extend your application and only want to switch to WCF so that you are using it, no. :-)
WCF will give you some more flexibility - you could for example consume data in other data formats or from other transport formats (Named Pipes, ...)
I hope i understood your question correctly !!!
The use of WCF lies where you know that both the sending as well as receiving end share the same data contract.
I think in your case, using WCF will benefit if both are MS application and the contract is not supposed to change very frequently.
We have a Requirement of Consuming the WCf Services which is hosted in IIS like http://localhost/someservice.svc.
We would like to consume that Service via java script and bind my sample data controls called grid view on client side itself.
I think this can be done by Serializing and deserialzing to JSON and consume the data source and bind the grid controls.
Pls Refer the below link
http://forums.infragistics.com/forums/p/48035/258346.aspx
I would like to Achieve my func like the above link.
Can you pls guide me to achieve this Tasks.
Thanks
Regards
N.Balaji
Balaji,
Yes, you can definitely enable your WCF service (whether within IIS or not) to use JSON.
You do need to make one choice: do you want to use that service from the ASP .NET AJAX framework, or do you want to create a more general solution that is not tied down to that framework's usage within the browser?
If it's the former, use WebScriptEnablingBehavior. If it's the latter, use WebHttpBehavior.
For either scenario, detailed instructions are available in the following two MSDN sections:
AJAX Integration and JSON Support
WCF Web Http Programming Model
I have a VB.NET web service that calls a third party web service. How can I view the SOAP message generated by .NET before it is sent to the third party web service and how can I see the SOAP response before it is serialized by .NET.
When creating a standalone EXE, I see the Reference.vb file that is automatically generated, but don't see a similar file when my project is a web service. I have found lots of C# code to do this, but none in VB.NET.
Edit - Fiddler and TCP loggers are great, but will not work for my purposes. I need to be able to access the raw SOAP messages from within the application so I can log them or modify them. I need to do more than just see the messages going back and forth.
You can use fiddler or a tcp sniffer to filter and identify all outgoing and incoming traffic on your host.
This is if you want to see the xml request and response.
How about using an extension to allow you to examine the SOAP message?
Accessing Raw SOAP Messages in ASP.NET Web Services
http://msdn.microsoft.com/en-us/magazine/cc188761.aspx
I was trying to do the same thing and this seems to work for me:
Dim message As String = OperationContext.Current.RequestContext.RequestMessage.ToString()
I didn't think it would be that easy since most of the time ToString() returns the name of the class, but I tried it out and low and behold.
I know you asked this back in January so if since then you've figured out a better way let me know.
Please note that if you're catching the exception in a class that implements IErrorHandler then you have to perform this operation from within the ProvideFault() method instead of the HandleError() method because the context is closed before it gets to call the HandleError() method.
Hope this helps.