The following example shows how you can expand/collapse branches in a Flex Tree control by clicking on the row instead of having to click on the disclosure/arrow icon.

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/04/05/opening-branches-by-clicking-rows-in-a-tree-control-in-flex/ -->
<mx:Application name="Tree_itemClick_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">
 
    <mx:Script>
        <![CDATA[
            import mx.collections.ICollectionView;
            import mx.events.ListEvent;
 
            private function tree_itemClick(evt:ListEvent):void {
                var item:Object = Tree(evt.currentTarget).selectedItem;
                if (tree.dataDescriptor.isBranch(item)) {
                    tree.expandItem(item, !tree.isItemOpen(item), true);
                }
            }
 
            private function tree_labelFunc(item:XML):String {
                var children:ICollectionView;
                var suffix:String = "";
                if (tree.dataDescriptor.isBranch(item)) {
                    children = tree.dataDescriptor.getChildren(item);
                    suffix = " (" + children.length + ")";
                }
                return item[tree.labelField] + suffix;
            }
        ]]>
    </mx:Script>
 
    <mx:XML id="dp">
        <root>
            <folder label="One">
                <folder label="One.A">
                    <item label="One.A.1" />
                    <item label="One.A.2" />
                    <item label="One.A.3" />
                    <item label="One.A.4" />
                    <item label="One.A.5" />
                </folder>
                <item label="One.1" />
                <item label="One.2" />
            </folder>
            <folder label="Two">
                <item label="Two.1" />
                <folder label="Two.A">
                    <item label="Two.A.1" />
                    <item label="Two.A.2" />
                </folder>
            </folder>
        </root>
    </mx:XML>
 
    <mx:Tree id="tree"
            dataProvider="{dp}"
            showRoot="false"
            labelField="@label"
            labelFunction="tree_labelFunc"
            width="300"
            rowCount="6"
            itemClick="tree_itemClick(event);" />
 
</mx:Application>

View source is enabled in the following example.

 
About The Author

Peter deHaan

Peter deHaan currently works for Adobe on the Flex SDK QA team. While not working on Flex, Flash, and ColdFusion applications, Peter enjoys making up bios and writing in 3rd person. Peter's rarely updated blog can be found at blogs.adobe.com/pdehaan/, actionscriptexamples.com, airexamples.com, and coldfusionexamples.com.

29 Responses to Opening branches by clicking rows in a Tree control in Flex

  1. eternalko says:

    Hi Peter!!!

    This is what I was looking for!!!

    THANK YOU!!

    eternalko

  2. Klaus Busse says:

    Hi Peter,

    great and very useful :-)

    Klaus

  3. coco says:

    thanks,good example!

  4. Yair says:

    How do I translate this example to use in an advanceddatagrid?

    Thanks,
    Yair

  5. Xyrer says:

    You amaze me with every post, thanks a lot.

  6. James says:

    OMG have been trying to find this for ever. Would be nice to see a XML populate this navigation with subcategories, would be killer!

  7. lwz7512 says:

    very useful sample, I have used it in our project!
    thanks!

  8. nwebb says:

    Thanks.

    Just a note – it looks like the itemOpen and itemClose events don’t get dispatched when you click on the row (only when you click on the arrow), so you may need to dispatch them manually:

    private function tree_itemClick(evt:ListEvent):void {
        var item:Object = Tree(evt.currentTarget).selectedItem;
        var eventType:String;
        if (tree.dataDescriptor.isBranch(item)){
            tree.expandItem(item, !tree.isItemOpen(item), true);
            // Clicking on anything other than the arrow doesn't dispatch the
            // normal Tree events, so manually dispatch...
            eventType = (tree.isItemOpen(item)) ? TreeEvent.ITEM_OPEN : TreeEvent.ITEM_CLOSE;
            var event:TreeEvent = new TreeEvent(eventType);
            event.item = item;
            tree.dispatchEvent(event);
        }
    }
    
  9. peterd says:

    nwebb,

    Great tip, thanks!

    Peter

  10. Jim Thompson says:

    Is there a way to keep the folders from getting selected with the highlight. They can highlight on rollover, just not persist the highlight on click.

  11. Tom says:

    Dont work, for dispatch this event you have to use the internal function dispatchTreeEvent!

    1 – import mx.core.mx_internal;
    2 – use namespace mx_internal;
    3 – dispatchTreeEvent(TreeEvent.ITEM_OPENING,
    item, //item
    this, //renderer
    evt, //trigger
    !isItemOpen(item), //opening
    true, //animate
    true) //dispatch

    mx_internal allow to access to ‘private’ members and is very usefull (another example is for the VideoDisplay to enable the smoothing)

  12. Kalpesh says:

    Is it possible to make wordwrape for TExt…Or is it possible ot make variable row height with tree control….

  13. Gerry says:

    Great work!

    Could you please tell me how to handle the item_click stuff in reference to an ADVANCEDDATAGRID.

    Many thanks in advance.

    Gerry

  14. Thanks Peter, Great stuff!

  15. John says:

    I’d like to see an example of this with AdvancedDataGrid as well!

  16. GT says:

    Hi all.

    For those who want to apply the same logic to an ADG, here’s what I did (I’m an amateur, so be gentle if the coding turns out to contain woeful inefficiency)…

    private function adg_itemClick(evt:ListEvent):void {
        var item:Object = AdvancedDataGrid(evt.currentTarget).selectedItem;
        totList.expandItem(item, !totList.isItemOpen(item), true);
    }
    

    It worked perfectly. I got rid of the if test because I couldn’t find the adg crollary to the dataDescriptor.isBranch bizzo. (‘Bizzo’ is an Australian technical term, meaning ‘something I dont really understand’… I understand if you aren’t familiar with it)

    ‘totList’ is the adg to which this function is applied as an itemClick.

    As usual, flexexamples has given me something that solves a problem – with my role being to find out how to bash the example to fit my project.

    Cheerio

    GT
    France

    PS sorry for not uttingthe code in acode frame – I can’t see how to do that.

  17. Lee Probert says:

    Just to confirm … with the AdvancedDataGrid not checking if the clicked item is a branch doesn’t seem to matter. The only thing that confused me is the AdvancedDataGridItemSelectEvent in FB3 that the compiler doesn’t like … you need to use a standard ListEvent … ho-hum! Also, while I’m at it … if you’re wondering how to assign different Item renderers for different branches look in the Flex help at the <mx:rendererProviders> tag … this was very handy!

  18. Steven Walter says:

    Is there a way to get the actual item from a itemRollover event when using an advanced datagrid that is grouped from a flat arraycollection? With the original datagrid you could simply get the item using this method on the event:

    event.currentTarget.dataProvider.getItemAt(event.rowIndex))

  19. DjKermit says:

    About that close/open event dispatching, look at fourth parameter of expandItem method (dispatchEvent:Boolean = false). Set it to true and it will work just fine.

  20. Senthil says:

    How to get the exact value from a itemRollover event when using an advanced datagrid

  21. Vijay Mareddy says:

    For ADG u need to use the ADGGroupItemRenderer:

    public class MyAdvancedDataGridGroupItemRenderer extends AdvancedDataGridGroupItemRenderer {
        private var _listOwner:AdvancedDataGrid;
        private var _listData:AdvancedDataGridListData;
    
        public function MyAdvancedDataGridGroupItemRenderer(){
            super();
        }
    
        override public function set listData(value:BaseListData):void {
            super.listData = value;
            if (value) {
                _listData = value as AdvancedDataGridListData;
                _listOwner = value.owner as AdvancedDataGrid;
    
                label.addEventListener(MouseEvent.MOUSE_OVER,
                    function(event:MouseEvent):void {
                        _listOwner.contextMenu = myContextMenu();
                        event.stopImmediatePropagation();
                    });
    
                label.addEventListener(MouseEvent.MOUSE_OUT,
                    function(event:MouseEvent):void {
                        _listOwner.contextMenu = null;
                        event.stopImmediatePropagation();
                    });
    
                addEventListener( MouseEvent.CLICK,
                    function(event:MouseEvent):void {
                        _listOwner.expandChildrenOf(_listData.item, !_listData.open);
                        event.stopImmediatePropagation();
                    });
            }
        }
    
        private function myContextMenu():ContextMenu {
            var contextMenu:ContextMenu = new ContextMenu();
            contextMenu.hideBuiltInItems();
    
            var expandCollapseItem:ContextMenuItem = new ContextMenuItem("Expand/Collapse Item",false,true,true);
            expandCollapseItem.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT,
                function(event:ContextMenuEvent):void {
                    _listOwner.expandItem( _listData.item, !_listData.open, false, false,null);
                    event.stopImmediatePropagation();
                });
            contextMenu.customItems.push(expandCollapseItem);
    
            var expandCollapseChildrenOf:ContextMenuItem = new ContextMenuItem("Expand/Collapse Children Of",false,true,true);
            expandCollapseChildrenOf.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT,
                function(event:ContextMenuEvent):void {
                    _listOwner.expandChildrenOf(_listData.item, !_listData.open);
                    event.stopImmediatePropagation();
                });
            contextMenu.customItems.push(expandCollapseChildrenOf);
            /**
             *     collapseAll/expandAll  is causing
             *     Error #1502: A script has executed for
             *     longer than the default timeout period of 15 seconds.
             */
            //            var collapseAllMenuItem:ContextMenuItem = new ContextMenuItem("Collapse All Groups",true,true,true);
            //            collapseAllMenuItem.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT,
            //                function(event:ContextMenuEvent):void {
            //                    _listOwner.collapseAll();
            //                });
            //            contextMenu.customItems.push(collapseAllMenuItem);
            //
            //            var expandAllMenuItem:ContextMenuItem = new ContextMenuItem("Expand All Groups",false,true,true);
            //            expandAllMenuItem.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT,
            //                function(event:ContextMenuEvent):void {
            //                    _listOwner.expandAll();
            //                });
            //            contextMenu.customItems.push(expandAllMenuItem);
    
            return contextMenu;
        }
    
    • Bhargav says:

      Hey Vijay,
      I understand this is a very old post for you. But I was trying to implement your idea for an ADG but in vain.

      Can you please explain your code or provide me a project file ofcorse alongwith the whole working code?

      Bhargav

  22. Sam says:

    Hi,

    Nice example. Can you explain how to display only the nodes we want ?

    For example, in your XML, you have “folder” nodes and “item” nodes, and I would like to only show “folder” nodes.

    Is it possible ?

    Thanks,

    Sam

  23. Jason says:

    Thank you very much for this example, it helped me optimise my own code!

  24. Ron says:

    Could someone please help me, how do you get the depth of a node in an advanced Data grid.

  25. kubarium says:

    Hi,

    I have been trying the same trick for FileSystemTree in AIR but it does not work.

    When I click on the row, I see the triangle looking down. I click again, it goes back to its initial position. I trace if the branch is open and get false/true so no problem there. However, the tree structure does not update itself. Moreover, if I happen to click on the triangle first, then everything works smoothly. There must be something about disclosure events, right?

  26. Matt says:

    Another great example!

  27. Elena says:

    Hi, very useful example indeed.
    I am a newbie so my question may sound stupid, what if you want to point to a specific object (aka folder) and not the whole tree?

    Thanks.

  28. shaman4d says:

    Animation on opening and closing doesn’t work. Could you help me?

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