[Flash 8/AS2] Skip over branches in XML?

programming flash
1

I have an tree component that is populated via XML. There are branch nodes and child nodes for each branch. This is a user interface for an elearning course. The branch nodes/folders in the tree component are for course sections and the child/leaf nodes for each are the content topics. each have a url attribute with a path to the appropriate content swf. The branch nodes/folders in the tree component do nothing when they are clicked on, as intended.

I also have previous/next buttons. They basically just navigate between leaf nodes. However, if the currently playing topic/leaf node is the first underneath a branch/folder, and I click on the ‘previous’ button, nothing happens. How can I set this thing to ‘skip over’ branch nodes? Here is the relevant code (the tree change listener, and the previous/next button event handlers:


var treeClickListener:Object = new Object();
treeClickListener.change = function() {
    var item = menu_ctr.selectedItem;
    var earl = item.attributes.url;
    nowPlaying = menu_ctr.selectedItem;
    if(earl) { //the var name 'earl' is equal to 'url' in xml, because url is a keyword in flash so shouldn't use it...
        content_cld.contentPath = earl;
        lessonName_txt.text = nowPlaying.attributes.unit + " : " + nowPlaying.attributes.lesson;
        //added 060208 - close the menu when user selects an item
        hideMenu();
        //set the 'demo' indicator if the content is a demo
        if (nowPlaying.attributes.demo == "yes")
        {
            demo_mc.gotoAndStop("on");
        } else {
            demo_mc.gotoAndStop("off");
        } cefe       
    }
}

menu_ctr.addEventListener("change",treeClickListener);

/***********************************************
* Navigation Buttons
***********************************************/
next_btn.onRelease = function()
{
    if (!nowPlaying.nextSibling)
    {
        return;
    } else
    {
        content_cld.contentPath = nowPlaying.nextSibling.attributes.url;
        nowPlaying = nowPlaying.nextSibling;
        lessonName_txt.text = nowPlaying.attributes.unit + " : " + nowPlaying.attributes.lesson;
        if (nowPlaying.attributes.demo == "yes")
        {
            demo_mc.gotoAndStop("on");
        } else {
            demo_mc.gotoAndStop("off");
        }        
    }
    
}

previous_btn.onRelease = function()
{
    if (!nowPlaying.previousSibling)
    {
        trace("No previousSibling");

    } else
    {
        content_cld.contentPath = nowPlaying.previousSibling.attributes.url;
        nowPlaying = nowPlaying.previousSibling;
        lessonName_txt.text = nowPlaying.attributes.unit + " : " + nowPlaying.attributes.lesson;
        if (nowPlaying.attributes.demo = "yes")
        {
            demo_mc.gotoAndStop("on");
        } else {
            demo_mc.gotoAndStop("off");
        }        
    }
}

Here is an excerpt from the XML file:


<tree>

	<folder label="PowerPoint-Based Movies">
		<link label="Subtopic One" unit="Unit One" lesson="Lesson One" url="content/SWFfromPPTslides/PPTSlide_RUSS_TEST_skin.swf" />
		<link label="Subtopic Two" unit="Unit Two" lesson="Lesson Two" url="content/mark1.swf" />
	</folder>

	<folder label="Captivate-Based Movies">
		<link label="Subtopic One" unit="Unit Three" lesson="Lesson Three" demo="yes" url="content/SWFofdesktop/test32_demo_skin.swf" />
		<link label="Subtopic Two" unit="Unit Four" lesson="Lesson Four" demo="yes" url="content/mark2.swf" />
		
		<folder label="Subfolder Example">
			<link label="Subtopic One" url="#" />
			<link label="Subtopic Two" url="#" />
		</folder>
	
	</folder>

</tree>
2

Solved it myself - just needed to think through the nextSibling/previousSibling/parentNode navigation methods better.


previous_btn.onRelease = function()
{
	if (!nowPlaying.previousSibling)
	{
		if (!nowPlaying.parentNode.previousSibling)
		{
			//do nothing, since there is no previous topic to play
			trace("there is no previous topic to play!");
			
		} else
		{
			//load previous leaf from previous branch
			content_cld.contentPath = nowPlaying.parentNode.previousSibling.lastChild.attributes.url;
			nowPlaying = nowPlaying.parentNode.previousSibling.lastChild;
		}

	} else
	{
		content_cld.contentPath = nowPlaying.previousSibling.attributes.url;
		nowPlaying = nowPlaying.previousSibling;
		lessonName_txt.text = nowPlaying.attributes.unit + " : " + nowPlaying.attributes.lesson;
		if (nowPlaying.attributes.demo = "yes")
		{
			demo_mc.gotoAndStop("on");
		} else {
			demo_mc.gotoAndStop("off");
		}		
	}
}