>>"You often see people use delegates this way as well:
buttonComponent.addEventListener("click",Delegate.create
(this,onButtonClick));This is handy- but if you have to remove that listener at a point in time, you have no reference to it in order to remove it, so clean up becomes hard. I usually create a variable to hold the reference and pass it in: public var delegateItem:Function;" not true. you can use arguments.caller to remove the listener when adding it like that. obviously that is only doable in the handler function. On 4/12/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > My two cents - > > EventDispatcher you use as a mixin, which basically means its a class you > don't use solely on its own, and its purpose is to dynamically add > something to object you mix it into. The members or functions of that > mixin class basically get added to your class (to the prototype object - > someone feel free to correct me if I am wrong - this is my understanding). > EventDispatcher affords you 3 primary functions you use - > addEventListener,removeEventListener and dispatchEvent. Mixing in a class > is an effective way to get additional functionality without inheriting - > as AS doesn't support multiple inheritance. > > With EventDispatcher you can mix it in- in a couple of ways. You can > initialize the class itself to be a broadcaster > (EventDispatcher.initialize(this)), you can utilie composition and have an > object which will then be the event source ( like adding an object in > your class that takes care of all the broadcasting responsibilities) and > there's another way I havent' seen implemented too often where you pass > the class protoype - in fact the first time I saw this approach was on > darron schall's blog > (http://www.darronschall.com/weblog/archives/000100.cfm). > > Delegate is a class that basically delegates/proxies the call. IN the > past, to do somethign like load in xml and then call a function in the > class, you would often see people do something like: > > myXML=new XML()); > myXML.host=this;// or myXML["host"]=this; > myXML.onLoad=function(){ > this.host.parseLoadedXML(); > } > myXML.load("file.xml"); > > WITH Delegate it takes care of making sure items are called in the scope > you designate, taking the scope/object and the function it should fire. > myXML=new XML()); > myXML.onLoad=Delegate.create(this,parseLoadedXML); > myXML.load("file.xml"); > > Delegate returns you a function. You can retain a reference to that > function by going somethign like: > var d:Function=Delegate.create(this,onHandleMethod); > > You often see people use delegates this way as well: > buttonComponent.addEventListener("click",Delegate.create > (this,onButtonClick)); > > This is handy- but if you have to remove that listener at a point in time, > you have no reference to it in order to remove it, so clean up becomes > hard. I usually create a variable to hold the reference and pass it in: > public var delegateItem:Function; > > delegateItem=Delegate.create(this,onButtonClick); > buttonComponent.addEventListener("click",delegateItem); > > > THen when i have to remove: > buttonComponent.removeEventListener("click",delegateItem); > > > I guess I am feeling verbose tonight. Anyone, jump in and correct me where > I might and possibly be wrong :) > > > > > > > > > > _______________________________________________ > [email protected] > To change your subscription options or search the archive: > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders > > Brought to you by Fig Leaf Software > Premier Authorized Adobe Consulting and Training > http://www.figleaf.com > http://training.figleaf.com > -- j:pn http://www.lennel.org _______________________________________________ [email protected] To change your subscription options or search the archive: http://chattyfig.figleaf.com/mailman/listinfo/flashcoders Brought to you by Fig Leaf Software Premier Authorized Adobe Consulting and Training http://www.figleaf.com http://training.figleaf.com
