Actually, you don't want to do either option. You want to implement getChildren to return a separate array collection for each collection of children. This is because the individual sets of children are tracked an managed by the tree so you can't reuse one collection instance, and you should not return different instances for the same set of children, otherwise one part of the tree code will make changes that some other part will not notice. Look at the default descriptor and see that it caches the AC instances per node/children set
________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of florian.salihovic Sent: Thursday, November 29, 2007 4:27 PM To: [email protected] Subject: [flexcoders] ListCollectionView#removeAll wants to dispatch undefined Currently i write a lil' component to display class hierachies. I wrote my own TreeDataDescriptor. SInce i work with my own class-, packages- and interface-descriptor classes to describe the structure, i encapsule some ArrayCollection. In order to display the structures in a tree, i need to melt them together in one ArrayCollection. So far so good... Since i want not to create a new ArrayCollection everytime the ITreeDataDescriptor#getChildren is called, i thought to create one ArrayCollection and remove all items when the function is called. I thought it would be ok to create a new field (typed: ArrayCollection) for the class. But actually the forces my component to crash. Here's the code: <pre><code> public function getChildren(node:Object, model:Object=null):ICollectionView { trace(this._className+"#getChildren"); try { if(node is PackageDescriptor) { this._children.sort = null; /*try { this._children.removeAll(); this._children.refresh(); } catch (e:Error) { trace("Error: "+e.message) } catch (e1:StackOverflowError) { trace("StackOverflowError: "+e1.message); } catch (e2:CollectionViewError) { trace("CollectionViewError: "+e2.message); } catch (e3:ArgumentError) { trace("ArgumentError: "+e2.message); }*/ trace("\tnode.className: "+PackageDescriptor(node).className); this._children = new ArrayCollection(); var packageDescriptor:PackageDescriptor = PackageDescriptor(node); for (var i:uint = 0; i<packageDescriptor.packages.length; i++) { this._children.addItem(PackageDescriptor(packageDescriptor.packages.getI temAt(i))); } for (var j:uint = 0; j<packageDescriptor.classes.length; j++) { this._children.addItem(ClassDescriptor(packageDescriptor.classes.getItem At(j))); } for (var k:uint = 0; k<packageDescriptor.interfaces.length; k++) { this._children.addItem(InterfaceDescriptor(packageDescriptor.interfaces. getItemAt(k))); } /*for (var l:uint = 0; l<this._children.length; l++) { trace("\t\t"+l+": "+this._children.getItemAt(l).name); }*/ return this._children; } } catch (e:Error) { trace("Error: "+e.message) } catch (e1:StackOverflowError) { trace("StackOverflowError: "+e1.message); } catch (e2:CollectionViewError) { trace("CollectionViewError: "+e2.message); } finally { return _children; } }</code></pre> So why is it at this point wrong to call removeAll to remove all references from the ArrayCollection instead of creating a new ArrayCollection all the time? The code above compiles. If i uncomment the first try/ctach statement, the application crashes.
