Friday, May 30, 2003 07:32 AM
The Web is the difference. With a Web client browser and Web server, talking via HTTP over a network, communication only occurs by discrete client request, and discrete server response. So there is a disconnect, preventing the accurate implementation of the original MVC pattern.
Unlike real MVC where the GUI "view" is constantly updated by the controller, to reflect changes in the model, on the Web (hence Model 2) the "view" is split, between the client Web browser and the front end of the server (e.g. JSP's). In the client Web browser, the display can only be updated if the client itself initiates a discrete request, and gets back a discrete response from the server. Hence the MVC2 or "Model 2", to try and account for this split gap in the middle of the "view" tier.