In GWT, all the server request will happen based on RPC request. In vaadin what is communication methodology?
Both the client code and server code sat inside the same place. Meaning there is no separation for client and server which is not true for GWT.
Could any one clarify me?
For example i have a button in vaadin. Finally this is rendered using GWT client rendering engine and producing some UI. In vaadin i have attached an action listener with this button. If i click this button, my listener will be invoked. So how the communication is happening here?
in Vaadin, the framework core does all communication for you. Your UI code, which actually runs on the server, just receives click and other events like regular application.
As for your example - when client-side button instance (which is autogenerated for you by the vaadin rendering engine) is clicked, the click event code is transmitted by the framework to the server, where it decoded and pushed into the server-side event queue, thenfinally delivered to all your button event listeners.
Again, when you, for instance, change button’s text, the change request is queued by the framework and sent to the client on next communication cycle, where it is received by the client rendering engine, decoded and applied to the actual GWT button instance, changing it’s title.
You may be also interested reading the “Book of Vaadin” which can be downloaded from this site, it has a nice chapter describing how the framework is functioning - http://vaadin.com/book