Move elements in an ArrayCollection – FLEX

actionscript-3apache-flex

Can someone lead me to SHIFT an element in an ArrayCollection in flex?

I have an ArrayCollection of sorted objects.

Now i need to move a row to the end of the ArrayCollection.

To illustrate, 

arrayCollection = ["Cars","Other","Trucks"];

This ArrayCollection is sorted. Now i need to move 'Other' to the end of the ArrayCollection. i.e., I need the array to be restructured as

arrayCollection  = ["Cars","Trucks","Other"];

Here is my code,

if(Index != -1){ 
CategoryList.addItem(CategoryList.removeItemAt(Index)); 
trace(CategoryList.source.join());}

'CategoryList' is an ArrayCollection of length 28, with 3 attributes for each object in the ArrayCollection.

'RemoveItem' works fine, but'AddItem' throws this error,

RangeError: Index '28' specified is out of bounds.
at mx.collections::ArrayList/addItemAt()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ArrayList.as:305]
at mx.collections::ListCollectionView/addItemAt()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:501]
at mx.collections::ListCollectionView/addItem()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:470]
at components::Home/creationOver()[C:\Documents and Settings\immanuel\My Documents\Flex Builder 3\Porj\src\components\Home.mxml:113]
at components::Home/___Home_Canvas1_creationComplete()[C:\Documents and Settings\immanuel\My Documents\Flex Builder 3\Porj\src\components\Home.mxml:2]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298]
at mx.core::UIComponent/set initialized()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:1169]
at mx.managers::LayoutManager/doPhasedInstantiation()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\LayoutManager.as:718]
at Function/http://adobe.com/AS3/2006/builtin::apply()
at mx.core::UIComponent/callLaterDispatcher2()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8628]
at mx.core::UIComponent/callLaterDispatcher()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8568]

I then try to insert at a specific position, 

CategoryList.addItemAt(CategoryList.removeItemAt(Index), CategoryList.length-1);

But this, throws the below error,

TypeError: Error #1006: value is not a function.
at mx.collections::ListCollectionView/getFilteredItemIndex()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:564]
at mx.collections::ListCollectionView/addItemsToView()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:896]
at mx.collections::ListCollectionView/listChangeHandler()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:1051]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.collections::ArrayList/internalDispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ArrayList.as:510]
at mx.collections::ArrayList/addItemAt()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ArrayList.as:311]
at mx.collections::ListCollectionView/addItemAt()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:501]
at components::Home/creationOver()[C:\Documents and Settings\immanuel\My Documents\Flex Builder 3\Porj\src\components\Home.mxml:113]
at components::Home/___Home_Canvas1_creationComplete()[C:\Documents and Settings\immanuel\My Documents\Flex Builder 3\Porj\src\components\Home.mxml:2]
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298]
at mx.core::UIComponent/set initialized()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:1169]
at mx.managers::LayoutManager/doPhasedInstantiation()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\LayoutManager.as:718]
at Function/http://adobe.com/AS3/2006/builtin::apply()
at mx.core::UIComponent/callLaterDispatcher2()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8628]
at mx.core::UIComponent/callLaterDispatcher()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:8568]

Best Answer

var array:Array = ["Cars", "Other", "Trucks"];
pushToEnd(array, 1);

trace(array.join()); //Cars,Trucks,Other

/**
* Removes the item at 'index' and pushes it to the back of the array.
*/

function pushToEnd(array:Array, index:Number):void
{
  array.push(array.splice(index, 1)[0]);
}

It's easier with an ArrayCollection

arrayCol.addItem(arrayCol.removeItemAt(index));

UPDATE: Working sample - see it for yourself.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" 
    creationComplete="create();">
    <mx:Button label="push" click="handle();"/>
    <mx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;

            private var ac:ArrayCollection;

            private function handle():void
            {
                ac.addItem(ac.removeItemAt(1));
                trace(ac.source.join());
            }

            private function create():void
            {
                ac = new ArrayCollection(["asd", "qwe", "zxc", "123"]);
                trace(ac.source.join());
            }
        ]]>
    </mx:Script>
</mx:Application>
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