Creating Hierarchical ArrayCollection out of Flat Array Collection where each record has three fields ID, Name, PID (say)

Here my flat array collection was having three fields ZZCUST_VEND (ID),ZZNAME (name),ZZHCUST_VEND(PID) and sample data would be like

            var flatArrayCollection:ArrayCollection = new ArrayCollection([
            {ZZCUST_VEND:"1", ZZNAME:"A", ZZHCUST_VEND:"0"},
            {ZZCUST_VEND:"2", ZZNAME:"B", ZZHCUST_VEND:"0"},
            {ZZCUST_VEND:"3", ZZNAME:"C", ZZHCUST_VEND:"0"},
            {ZZCUST_VEND:"4", ZZNAME:"D", ZZHCUST_VEND:"0"},
            {ZZCUST_VEND:"5", ZZNAME:"A1", ZZHCUST_VEND:"1"},
            {ZZCUST_VEND:"6", ZZNAME:"B1", ZZHCUST_VEND:"2"},
            {ZZCUST_VEND:"7", ZZNAME:"C1", ZZHCUST_VEND:"3"},
            {ZZCUST_VEND:"8", ZZNAME:"A11", ZZHCUST_VEND:"5"},
            {ZZCUST_VEND:"9", ZZNAME:"B11", ZZHCUST_VEND:"6"},
            {ZZCUST_VEND:"10", ZZNAME:"C11", ZZHCUST_VEND:"7"},
            {ZZCUST_VEND:"11", ZZNAME:"D1", ZZHCUST_VEND:"4"},
            {ZZCUST_VEND:"12", ZZNAME:"D11", ZZHCUST_VEND:"11"},
            {ZZCUST_VEND:"13", ZZNAME:"E", ZZHCUST_VEND:"0"},
            {ZZCUST_VEND:"14", ZZNAME:"E1", ZZHCUST_VEND:"13"},
            {ZZCUST_VEND:"15", ZZNAME:"C12", ZZHCUST_VEND:"7"},
            ]);
 

<---------------------------------TreeNodeH in package components----------------------------------------------------------------->

package components
{
    import mx.collections.ArrayCollection;
    
    public class TreeNodeH
    {
        public var id:String;
        public var name:String;
        public var pid:String;
        public var children:ArrayCollection;
       
        public function addChild(node:TreeNodeH):void
        {
            if(this.children == null)
            {
                this.children = new ArrayCollection();
            }
            children.addItem(node);
        }
        public function TreeNodeH()
        {
        }

    }
}

<------------------------TreeCreator Class------------------------------>

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                TREE UTILITY CLASS                                                                                               //
//                USED TO CREATES HIERARCHICAL COLLECTION    OUT OF FLAT ARRAY COLLECTION WHERE EACH RECORD HAS (ID,NAME,PID).     //                                                                                                              //
//                Akhil Mittal                                                                                                     //
//                                                                                                                                 //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

package util
{
    import mx.collections.ArrayCollection;
    
    public class TreeCreator
    {
        public function TreeCreator()
        {
        }
        /*
            This function is used to insert a child node (childNode) under its parent node (node).
        */
        public static function insertchildForNode(node:TreeNodeH, childNode:Object):void
        {
            if(node.children == null)
            node.children = new ArrayCollection();
           
            var newChild:TreeNodeH = new TreeNodeH();
            newChild.id = childNode.idTab; //Id for every record in collection is idTab.
            newChild.name = childNode.nameTab;    //Name for every record is nameTab.
            //newChild.parentId and node.id will be same.
            newChild.pid = childNode.parentIDTab;    //Parent ID will be parentIDTab
            node.children.addItem(newChild);
        }
        /*
            This function is used to create a hierarchical collection out of Flat Array collection.
        */
         public static function createHierarchicalArrayCollection(flatArrayCollection:ArrayCollection):TreeNodeH
        {
            //First create a root node, but it wont be shown ultimately.
            var top:TreeNodeH = new TreeNodeH();
            top.name = "root";
            top.id = "0";    //ID for the root will be 0 so that all the nodes with zero PID would be added under this.
            top.pid = "-1";
           
            //Now for every node find its parent and add the current node to the parent.
            var parentNode:TreeNodeH = new TreeNodeH();
            for(var i:int = 0; i<flatArrayCollection.length;i++)
            {
                var currentRecord:Object = flatArrayCollection.getItemAt(i) as Object;
               
                //Find its proper parent reference
                if(currentRecord.parentIDTab == "0")
                    parentNode = top;
                else
                    parentNode = searchTreeForParentNode(currentRecord.parentIDTab,top);
               
                //If parent is found then add this node to parent.
                if(parentNode != null)
                    insertchildForNode(parentNode,currentRecord);
            }
            //Top is the root of that created tree.
            return top;
        }
       
        /*
            This function is used to search parent node for the node having PID as parentID. This is classic Breadth First Search
            and will start from the top node (rootNode).
        */
        public static function searchTreeForParentNode(parentID:String,rootNode:TreeNodeH):TreeNodeH
        {
            var openList:ArrayCollection = new ArrayCollection();
            openList.addItem(rootNode);
           
            var index:int = 0;
            while (openList.length != 0)
            {
                var node:TreeNodeH = openList.getItemAt(index) as TreeNodeH;
               
                if(parentID == node.id)
                {
                    return node;
                }
               
                var nodeChildsList:ArrayCollection = node.children;
                if(nodeChildsList != null)
                {
                    var nLength:int = nodeChildsList.length;
                    for(var i:int=0; i<nLength;i++)
                    {
                        var currentItem:TreeNodeH = nodeChildsList.getItemAt(i) as TreeNodeH;
                        openList.addItem(currentItem);
                    }            
                }
                index++;                
            }
            //Node Not found.
            return null;
        }
    }
}

Application can use this like:

[Bindable]
public var hierarchicalArrayCollection:ArrayCollection = new ArrayCollection();
var rootNode:TreeNodeH = TreeCreator.createHierarchicalArrayCollection(flatArrayCollection);
hierarchicalArrayCollection.addItem(rootNode);

<mx:Tree height="100%" width="100%" showRoot="true" allowMultipleSelection="true"/>