Re: [flexcoders] Re: need strategy for filtering ArrayCollections in a Cairngorm app

[Tom Bray]

The problem is that changes to ModelLocator.getInstance().masterArray don't update the views' dataProviders.  In other words, the ArrayCollections that use masterArray as their source don't know when new items are added to or removed from masterArray.  That's why I was thinking that masterArray would actually be masterArrayCollection and I'd bind each of the view's dataProvider ACs to it so they could stay in sync.  I bound the master AC to the sub ACs using BindingUtils and was surprised to see the filter function on the sub ACs affect the master AC.  I posted sample code here: 
http://groups.yahoo.com/group/flexcoders/message/39064?l=1Thanks again!-TomOn 6/9/06, 
Tim Hoff <[EMAIL PROTECTED]> wrote:









  


    
            
Something like this should do the trick:

<mx:Script>
    <![CDATA[

import mx.collections.ArrayCollection;
       import org.ets.main.code.model.ModelLocator;

[Bindable]
       public var viewDataProvider : ArrayCollection;
       viewDataProvider=new
ArrayCollection({ModelLocator.getInstance().masterArray});

]]>
</mx:Script>

-TH

--- In flexcoders@yahoogroups.com, "Tom Bray" <[EMAIL PROTECTED]> wrote:
>
> Thanks, Tim. That makes sense but there's one limitation I'm not sure
how
> to work around. That master Array of users is going to be constantly
updated
> by the server to show who's currenlty online. Since an Array isn't
> bindable, how would you propagate changes from that Array to the
filtered
> ArrayCollections that use it as their source?
>
> -Tom
>
> On 6/9/06, Tim Hoff [EMAIL PROTECTED] wrote:
> >
> > Hey Tom,
> >
> > In response to this question and the BindingUtils and
> > ArrayCollection.filter question, I offer this suggestion. In the
> > ModelLocator maintain a single master Array of all the users. Then
> > in each instance of your view components, create a new bound
> > ArrayCollection (dataProvider), with the master Array as the
> > underlying source. Each of the ArrayCollections will have a
> > different filterFunction based on the type of view component that is
> > instantiated. Because the ArrayCollections don't actually contain
> > any data, just pointers to the underlying Array, I would handle the
> > ArrayCollections and filterFunctions in viewHelpers. In a sense,
> > you would be creating separate sub-sets of the master Array in each
> > instance of your views. If you preferred, you could maintain each
> > ArrayCollection (Array of ArrayCollections) in the ModelLocator as
> > well.
> >
> > I hope that this makes sense,
> > Tim Hoff
> >
> >
> > --- In flexcoders@yahoogroups.com <flexcoders%40yahoogroups.com>,

"Tom
> > Bray" tombray@ wrote:
> > >
> > > Say my model has an ArrayCollection of all the users that are
> > > connected to my Flex app. I then have configurable list views that
> > > display different subsets of that collection based on different
> > user
> > > properties (gender, age, location, etc.). Multiple views, multiple
> > > filters, all being fed from the same master ArrayCollection of all
> > > connected users. I even want the user to be able to dynamically
> > > create new views with different filters.
> > >
> > > Unless there's something I'm missing, each view is going to need
> > its
> > > very own ArrayCollection that has its own filter function set up.
> > I'm
> > > picturing a wrapper class that provides addFilter() and
> > removeFilter()
> > > methods so that the AC's filter function can traverse an array of
> > > other filters -- kind of a CompoundCommand pattern.
> > >
> > > Assuming that's part of the correct approach, I want my master AC
> > to
> > > pump changes out to the filtering ACs which pump changes out to
the
> > > views. Is there a way to make the binding mechanism work for this?
> > > Is there a simpler approach I'm overlooking?
> > >
> > > Any tips you can send my way would be greatly appreciated.
> > >
> > > Thanks,
> > >
> > > Tom
> > >
> >
> >
> >
>


      

    
    












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