RE: [CFCDev] Factory Pattern

[Scratch]

Are you proposing something along the following:   <!--- LOAD ---> <cffunction name="loadInit" access="public" returntype="any">             <cfargument name="Obj" type="string" required="yes" />             <cfinvoke method="create#arguments.ObjectName#" returnVariable="Instance" />                                     <cfreturn Instance /> </cffunction>   <!--- LOAD INIT ---> <cffunction name="loadInit" access="public" returntype="any">             <cfargument name="Obj" type="string" required="yes" />            <cfargument name="initArgs" type="struct" required="yes" />             <cfinvoke method="create#arguments.Obj#" returnVariable="Instance" initArgs=”#arguments.initArgs” />                                     <cfreturn Instance /> </cffunction>   <!--- createXXX ---> <cffunction name="createXXX" access="private" returntype="XXX">             <cfargument name="initArgs" type="struct" required="no" default=”structnew()” />             <cfset var Instance=createobject('Component','XXX').init(this, argumentscollection=arguments.initArgs) />                                                             <cfreturn Instance /> </cffunction>   I’m not sure what problem that would solve? You would still have to decipher which load to call. And to make that decision you would have to go back and find out if the object takes args or not – which brings right back where we started.   Maybe Barney’s way is best – you just let the factory create and pass empty dependent objects, and then later you set them by passing in stateful instances.   On a related note, remind me again why it’s better to create the dependent objects in the Factory rather than just creating them in the object’s init():   EXAMPLE A (Create in the Factory - this is supposed to be better) <!—createXXX à <cfset var DependentObject1=load(‘DependentObject1’) /> <cfset var DependentObject2=load(‘DependentObject2’) /> <cfset var Instance=createobject('Component','XXX').init(this, DependentObject1, DependentObject2) />   <!—XXX’s init() à <cfset variables.instance.Factory=arguments.Factory /> <cfset variables.instance.DependentObject1=arguments.DependentObject1/> <cfset variables.instance.DependentObject2=arguments.DependentObject2/>   EXAMPLE B (Create in the init() - why not this way again?) <!—createXXX à <cfset var Instance=createobject('Component','XXX').init(this) />   <!—XXX’s init() à <cfset variables.instance.Factory=arguments.Factory /> <cfset variables.instance.DependentObject1= variables.instance.Factory.load(‘DependentObject1’)  /> <cfset variables.instance.DependentObject2= variables.instance.Factory.load(‘DependentObject2’)/>   As long as you’re passing THIS to the init() from the Factory, you will still be creating your objects in a consistent and simple manner and have access to any config in the Factory.   In terms of maintenance, the second way seems cheaper.  If a dependent objects changes you only have to change the init(), whereas with the other way you have to change it in the init() AND Factory.   What do you think?   Baz           From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Nando Sent: Wednesday, November 02, 2005 4:31 AM To: CFCDev@cfczone.org Subject: RE: [CFCDev] Factory Pattern   I like the second one better, because it gives me a consistent interface to program to.   But it's true what you say that it's more confusing, because then you always have to check if an object needs args passed into it before calling Factory.load()   So what about another public interface for Factory? How about if we leave load() as it is so we're always clear about what it does and create a loadInit() method in Factory: (and yes, maybe there's a better name for it ... )   <!--- loadInit ---> <cffunction name="loadInit" access="public" returntype="any">             <cfargument name="ObjectName" type="string" required="yes" />            <cfargument name="initArgs" type="struct" required="YES" />     What do you think of that approach?   I'd definitely prefer that Factoryhandles the the init() for me in it's own black box, but i certainly have situations where i need to pass application state stuff into objects to instantiate them. It doesn't seem like it's within Factory's mandate to know "everything". And it certainly is unpredictable what some yet to be designed object may need in it's init() method, even if it always needs the same exact thing.   So how do you feel about providing 2 interfaces in Factory? load() and loadInit()?       -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Nando Sent: Wednesday, November 02, 2005 7:07 AM To: CFCDev@cfczone.org Subject: RE: [CFCDev] Factory Pattern :) - back so soon?   myInstance = application.Factory.load('myObj') myInstance.init(InitParametersCouldGoHere)    or what about this?   myInstance = application.Factory.load('myObj',args)   <!--- load ---> <cffunction name="load" access="public" returntype="any">             <cfargument name="ObjectName" type="string" required="yes" />            <cfargument name="args" type="struct" required="no" />     Which do you like better? If you prefer one over the other, why?     -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Scratch Sent: Wednesday, November 02, 2005 6:15 AM To: CFCDev@cfczone.org Subject: [CFCDev] Factory Pattern   I was recommended to build a Factory object to create my CFCs in the following manner:   <!--- init ---> <cffunction name="init" access="public" returntype="SystemFactory">             <cfreturn this /> </cffunction>   <!--- load ---> <cffunction name="load" access="public" returntype="any">             <cfargument name="ObjectName" type="string" required="yes" />               <cfset var ObjectInstance="" />               <cfinvoke method="create#arguments.ObjectName#" returnVariable="ObjectInstance" />                                     <cfreturn ObjectInstance /> </cffunction>   <!--- createObjectXXX ---> <cffunction name="createObjectXXX" access="private" returntype=" ObjectXXX ">                                     <cfset var Object=createobject('Component','SystemCFC.ObjectXXX).init() />                                                             <cfreturn Object /> </cffunction>   The load() method takes a CFC name and calls the appropriate Create() method. My app should only call load().   First off is this a good way? Secondly, if I use this way I seem to lose the ability to pass already instantiated objects to my init() methods - ofcourse I can still create new dependent objects and pass them in, which is the point of the whole thing, but what about passing in already instantiated objects? How does that work with Factories?   Anyone care to post a link to their Factory file ;-)   Cheers,   Baz ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. 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An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to cfcdev@cfczone.org with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). An archive of the CFCDev list is available at www.mail-archive.com/cfcdev@cfczone.org