Re: [CFCDEV] Questions migrating to OO

[Nando]

Hi, I think one of the most important points to keep in mind is to keep your design practical. A lot of times in introductory texts on OO you see objects like Airport, Airplane, Wing, JetEngine, Passenger, Pilot, etc ... and you get the impression that to build an application in OO, you need to put every concept you can think of in your design. Not so. If Airport isn't "doing anything" in your app, you don't need an object for it. So, for instance, you have here List Object - Would handle the overall lists. ??? What is a list? A collection of list items? Is that what you mean here? What defines a list? A unique name? Probably an ID (ListID)? Probably a UserID that identifies the list as belonging to a user. If i'm understanding you correctly, and your users need to create lists by giving them a name like "Shopping on Tuesday" - then you have a candidate for an object named "List". But it doesn't make sense to me at all that a list object would be stored in application scope. Why? Because you almost certainly have multiple lists in your application. I'd put it either in session scope, perhaps, if you're doing some sort of validation with the ListName for instance and you want to persist the form data in the List object, or just leave it in request scope. <cfcomponent displayName="List" hint="I'm a List that belongs to a certain User" output="false">         <cffunction name="init" access="public" output="false">         <cfargument name="ListID" type="string" required="false" default="" />         <cfargument name="UserID" type="string" required="false" default="" />         <cfargument name="ListName" type="string" required="false" default="" />         <cfset setListID(arguments.ListID) />         <cfset setUserID(arguments.UserID) />         <cfset setListName(arguments.ListName) />         <cfreturn this />      </cffunction>         <cffunction name="getListID" access="public" returntype="string" output="false">         <cfreturn variables.ListID />     </cffunction>     <cffunction name="setListID" access="public" returntype="VOID" output="false">         <cfargument name="ListID" type="string" required="true" />         <cfset variables.ListID = arguments.ListID />     </cffunction>     <cffunction name="getUserID" access="public" returntype="string" output="false">         <cfreturn variables.UserID />     </cffunction>     <cffunction name="setUserID" access="public" returntype="VOID" output="false">         <cfargument name="UserID" type="string" required="true" />         <cfset variables.UserID = arguments.UserID />     </cffunction>     <cffunction name="getListName" access="public" returntype="string" output="false">         <cfreturn variables.ListName />     </cffunction>     <cffunction name="setListName" access="public" returntype="VOID" output="false">         <cfargument name="ListName" type="string" required="true" />         <cfset variables.ListName = arguments.ListName />     </cffunction> </cfcomponent> So, if you have multiple lists, do you need an object to represent all of your lists? Called "AllMyLists" or "UserLists" perhaps? I don't think so. Why? Because your users will probably not need to perform any operations on all their lists at once ... especially in a way that would lead you to represent them all in a business (or collection) object. When Users are dealing with Lists, functionally, they do so One_At_A_Time. You can still have an option in your app to delete all your lists in a Gateway for instance. That's about the only thing i can think of that a user would want to do with all their lists at once. There's no need at all to load all a User's Lists (and ListItems!) into a UserLists object to delete them. There's no purpose to that. After the User clicks on a link that says Delete All My Lists, you just get them to confirm it somehow in the UI, and once the confirmation comes thru, you call DeleteAllUserLists() in a gateway function, passing in the UserID, and that function simply deletes all the lists of that user from the database. Does that help? Nando Hi, I'm still new to a lot of OO stuff and coding CF procedurally for a few years, and I had some questions! I'm trying to migrate this app I have to OO and run it under model-glue 2.0 (if that matters). It is a to-do list manager, similar to remember the milk et al, but in CF and run locally mostly for my dev tasks. Anyhow, I ALWAYS get tripped up in architecture when it comes to OO. If someone had a few minutes to scan the below and offer any opinions/advice it would be appreciated, I'm very green to this so shouting is acceptable :) Breakout ========= List Object - Would handle the overall lists. Stored in application.x + dao + gateway List Item Object - would handle specifically items in a list, and I guess would be a dependancy of the list object? Stored in application.x +dao +gateway User Object - would store username, roles, email etc. Stored in session.x +dao +gateway UserSecurity - would take a user object and perform password changing, role based security, etc. Stored in application.x You are subscribed to cfcdev. To unsubscribe, please follow the instructions at http://www.cfczone.org/listserv.cfm CFCDev is supported by: Katapult Media, Inc. We are cool code geeks looking for fun projects to rock! www.katapultmedia.com An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org -- Aria Media Sagl CP 234 6934 Bioggio Switzerland +41 (0)91 608 2404 +41 (0)76 303 4477 www.aria-media.com You are subscribed to cfcdev. To unsubscribe, please follow the instructions at http://www.cfczone.org/listserv.cfm CFCDev is supported by: Katapult Media, Inc. 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