WCF V ASP services for FTP access from Silverlight 4 Part 2
Apologies as this Post is not as detailed as I would like it to be but time pressure dictates. Last time I discussed using a HTTP generic handler to handle the uploading of local files to a FTP server. In this Post I am going to discuss the WCF service to report back on the progress of the uploads to the eventual destination. I use ASP HTTP generic Handlers for file uploads as they do not time out as readily as WCF web services. This is an observational point of view. I don’t see much discussion on the matter of suitability so any comments would be welcome. Below is the Architecture of Our latest app ( I’ve left out the RIA services <-> Database part for simplicity).
To my mind and in what I know of WCF web services they are suited for short message exchange between web clients and the services. Opinions?
So we use them here to monitor the Asynchronous delivery of local files from a Silverlight client to the FTP server VIA the HTTP generic handler.
I used Duplex Polling for this purpose. The method is based on the WCF fire starter video series on channel 9 and this a video by Tomasz Janczuk on Duplex communication Duplex Communication with WCF in Silverlight 4.
The second video explains the process well. The hardest part of WCF services is in getting the message timing right. The WCF service queries the FTP server and sends message back to the Silverlight 4 client that has subscribed to the the service. Time is a bit tight. So if anyone wants me to post details then lets hear from you and I will. A bit busy at the moment. Later.