All mixed up below > -----Original Message----- > From: Rosenberg, Leon [mailto:[EMAIL PROTECTED] > Sent: 16 November 2004 10:58 > To: Struts Users Mailing List; Dakota Jack > Subject: AW: talking about paradigms > > > Hi Jack, > > I like you kind of "cashing out", but I think your diagram > misses some points. In fact the view-controller itself is a > view on the application model, where the business logic unit > (which can be a component in a co-architecture i.e. > session-bean) is the appropriate controller. So a complex > mvc-architecture, contains more than one controller, but a > grid of smaller mvc cycles, each of them being the view on > the previous controller. > > You are partially right talking about Webframeworks as not > truly MVC, at least they do not have the possibility of > callbacks from controller to view (see also > subject/observer), but on the other hand, there is no need > for explicit back calling opportunity issued by Gamma as he > defined the MVC pattern. This why I think, we can still speak > about webframeworks as MVC, keeping in mind, that they are > solely client triggered. >
The design for web application is never not quite MVC as in the original Smalltalk definition / example, because of the limits of the HTTP / HTML protocols. Although stuff like Faces / Tapestry try there best to get around the missing update from the presentation (view) back to the controller. The classic MVC is the joystick (or input device) and model (map of a country) and several views ( GUIs anything you like such as VDUs, projectors). With the GUI programming in Swing ( and I think SWT) the controller and view are mashed together in a windows API. However you can still think of them as being separate because the windows API generates input event (mouse buttons and movement, keyboard keys) and incorporates a separate rendering pipeline (repaint this window or region of a window etc). With webapp and classic HTML development the notifications are broader than the windows API for operating system. Namely you can only have "Get me a next web page" and "Render a new page". Hence the multitude of solutions out there to make the notification more narrow, or fine-grain, from JSF, to MM Flex, to JDNC. I unable, personally, to see the landscape changing unless the underlying protocol HTTP is revisited by W3C. Maybe a universal standard will come along that will say "Fire event for this abstract webpage input" and a corresponding notification "Please just (re-)render for this abstract web component with the content I am sending you now". Yeap with baited breathe ... ==////== > > -----Ursprüngliche Nachricht----- > > Von: Dakota Jack [mailto:[EMAIL PROTECTED] > > Gesendet: Montag, 15. November 2004 20:46 > > An: Struts Users Mailing List; [EMAIL PROTECTED] > > Betreff: Re: talking about paradigms > > > > The whole discussion about MVC and web frameworks is important, I > > think, because not many cash it out when to do so (cash it > out) would > > be helpful for discussion. We might try some way of > refering to this > > such as WEBMVC. Anyway, the MVC pattern, taken literally, is > > impossible in a web framework. What is possible is > something like the > > following where the arrows indicate where there is a coupling: > > > > View <==> Controller <==> Model > > > > Here the Model and the View are completely decoupled. But, > even this > > is almost a total representation of what is really going > on. What is > > really going on is that the response object is ultimately HTML and > > that the JSP pages are part of creating the response object, so that > > JSP pages inherently provide a smart-serverside View. This > all is not > > simple to cash out. I have a sample beginning of cashing > this out at > > http://131.191.32.112:8080/ , which, if others want to provide > > alternative way of viewing this I will show them all. The most > > important thing, I think, is to distinguish between the > View data and > > the Model data. That is the distinction, I think, that > Craig makes in > > JSTL between iteration and sql statements in JSP. > > > > Jack > > > > > > -- > > "You can't wake a person who is pretending to be asleep." ==////== -- Peter Pilgrim Operations/IT - Credit Suisse First Boston, 10 South Colonnade, London E14 4QJ, United Kingdom Tel: +44-(0)207-883-4497 ============================================================================== This message is for the sole use of the intended recipient. If you received this message in error please delete it and notify us. If this message was misdirected, CSFB does not waive any confidentiality or privilege. CSFB retains and monitors electronic communications sent through its network. Instructions transmitted over this system are not binding on CSFB until they are confirmed by us. Message transmission is not guaranteed to be secure. ============================================================================== --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
