How about if let's say you use classes from an external library in you model? It won't even be in you project structure. it will be from your libs where the swc's reside...You can clone vo's into model classes but it seems such a waste to me ... C
________________________________ From: Jorge Maiquez <[email protected]> To: [email protected] Sent: Thursday, August 6, 2009 6:42:16 PM Subject: RE: [flexcoders] cairngorm convention: vo or model? Ok, so if I’m understanding you correctly, you don’t have a problem storing a VO in some part of the model (assuming that the VO is used for both transport and storage)? In my Cairngorm project, the directory structure looks like this: business control commands events model view vo So if I do what you suggest, and allow for a VO to reside in the model, then the model will contain stuff that does not reside in the model directory, which feels kinda weird to me. I know I’m being very fussy over something very trivial :-) From:flexcod...@yahoogro ups.com [mailto:flexcoders@ yahoogroups. com] On Behalf Of claudiu ursica Sent: 06 August 2009 16:01 To: flexcod...@yahoogro ups.com Subject: Re: [flexcoders] cairngorm convention: vo or model? You are right, If your data is only transport stuff and then get rid of it it does not justify to put it in the model. If you need your data displayed in the view then your data will probably be in the model. It depends on your business case. The VO is just a name in the end... you can label a class with VO or not it is how you use it what matters. You can transport data with VO objects (classes with no methods) and put it inside other model classes (put a clone method inside that class to move data from VO). But in many cases this is not justified. For example you want to login, you get the username and pass form the textfield inside a VO. Attach that VO as a payload to the cairngorm event and send it to the server via command/delegate etc ... That is a case where you just transport data ... no need ot store it in the model ... If you get data from the server like some products and want to display them in the view, you can pu them in the model and use the model as a dataprovider for a list or whatever ... C ________________________________ From:Jorge Maiquez <jmaiq...@yahoo. com> To: flexcod...@yahoogro ups.com Sent: Thursday, August 6, 2009 4:50:14 PM Subject: RE: [flexcoders] cairngorm convention: vo or model? What about transient data? I was always under the impression that VO’s (or DTO’s or whatever they’re called) were more like throw-away objects: you use them to transfer data to/from a server, but that’s it. So if I label something as being a VO (e.g. ConversationVO) , then I don’t expect to find that class in the “model” classpath because I am not storing data in it. Consequently, I would not expect my view to bind to it. Does that make sense? I guess all I’m asking is: would you label something as being a VO and then bind your view to it? Symantics, I know, but I’m trying to figure out whether I’m the only one who thinks it’s weird :-) From:flexcod...@yahoogro ups.com [mailto:flexcoders@ yahoogroups. com] On Behalf Of claudiu ursica Sent: 06 August 2009 14:23 To: flexcod...@yahoogro ups.com Subject: Re: [flexcoders] cairngorm convention: vo or model? Ultimately the data should be in the model, and the view binds to the model. However depending on your needs you could notify the view from the command using responders. Check the UM Cairngorm extensions for this. HTH, Claudiu ________________________________ From:Jorge Maiquez <jmaiq...@yahoo. com> To: flexcod...@yahoogro ups.com Sent: Thursday, August 6, 2009 3:07:15 PM Subject: [flexcoders] cairngorm convention: vo or model? I have a some doubts about implementing Cairngorm correctly (and I guess MVC in general). I’m trying to decide where to place some of my data storing/transferrin g classes, and I was wondering if anyone has any rules of thumb for this kind of thing. These are the guidelines that I have been following until now: 1) the class only transfers data to/from a server: postfix “VO” and put it in the vo folder 2) the class only stores data for the local application: put it in the model folder 3) the class does both of the above: put it in the model folder (don’t postfix “VO”) I’m working with someone who does (1) even when the class is never sent across the wire. What’s the “right” way to do this? And also: I’ve read somewhere that VO’s should not contain any logic, and that you should be able to initialise all of its properties via the constructor. What do you think? TIA! -Jorge
