We have a .NET Sales Web Application for which Offline capability needs to be added. i.e The users can access(read,edit,create) the leads,oppurtunities and prospects even if they are not connected to the network and later when they come online, automatic Syncronization needs to happen with the underlying database(which is Oracle).
We know that there is Google gears and Adobe AIR out there. Which is best suited for .NET web applications??
You need some kind of a thick-client to do this, a Java app, Flash or Silverlight. This will need to work when the browser is "offline" and store data locally until a reconnect is possible.
In a nutshell: Each user edit results on teh UI results in 'command' being generated. This command is send to backend using ajax. If server sesponds that it processed the command ok, then verything is fine. If server is not responsing, store the command in queue of waiting commands and start timer that will try to send this queue to server.
This isn't simple, you have to worry about concurrency(two users editing the same record), transactions, user closing browser, etc.
I do not think you can prevent loss of user changes when user closes his browser without Google Gears or something like that, that will allow you to store information on client side.
I've used the Cassini web server, embedded in a web form with a System.Windows.Forms.WebBrowser object to run a web application "offline". You can download the Cassini web server from this link: http://ultidev.com/download/.
Here's a post that may help you as well: Cassini Desktop Adapter : Standalone Web Applications