Thanks Jon, your comments are very helpful to me. - Oscar
--- In flexcoders@yahoogroups.com, Jon Bradley <[EMAIL PROTECTED]> wrote: > > > On Jul 10, 2008, at 11:33 AM, oscar.12321 wrote: > > > I seems to me that commands are not user gestures, nor clicks or > > backend queries. The only posible explanation to me is as use cases > > are abstract (What kind of things can the the user do?) so there is no > > a fixed rule. > > In my experience, use cases are more appropriately tied to events, > not commands. > > > In essence a methodology to identify commands could be: > > 1. Try to hold the view state in the view. > > Yea, but that's not necessarily always the case. Consider the states > Logged in/out. Those two states are application level and are > something that typically would be stored in the application model > locator. > > Remember, state can be global (application) or micro (mini mvc, or mv > only). You might have a portion of your application that works on, > say, a selected item, such as selecting an item and modifying it's > properties before adding it to a cart. This situation doesn't need a > selected item in the main application model. > > There are applications that, for example, might be geared toward > working on a collection of elements and all views and portions of the > application need to bind to that (not a storefront-type app). > > Let's say you write an image editing application. The selected image > that is being edited would be stored in the application model because > everything in the application aside from selecting the image to edit > performs operations on this selected image. > > Here you'd have the global 'selectedImage' property in the model that > views bind to, but then the view collections themselves may have a > local copy of that to work on (for undo/redo functionality, for > example). > > > 2. Determine the use cases, and make a command for each one. > > Not all the time. Some use cases are such that they kick off a chain > of events. For sake of argument, let's say 'addToCartEvent' has three > other events that need to occur before the final 'addToCartCommand" > is executed. Lots of things can happen in a use case life cycle. > > > 3. Any backend query is also a command. > > Not necessarily either. It may be a single command with a collection > of delegates. > > > 4. If you need to update the model from the view, don't do it > > directly. You have discovered a new command an probably a use case. > > That I do agree with. I never have my views modify the model > directly. That's generally frowned upon (though I'm sure there are > limited situations where this might be beneficial). > > just my 0.02. > > good luck with your experimentations with the framework. > > cheers, > > jon >
