determine position of an ordered list item

wac · 11-10-2004, 07:44 PM

I would like to determine the position of an LI in an ordered list. There's the 'value' attribute, but that's unfortunately deprecated. Is there any other way???

Roy Sinclair · 11-10-2004, 09:20 PM

Position relative to other LI items? Position relative to the browser window?

Sorry but you're not coming in clear yet.

wac · 11-12-2004, 04:19 PM

sorry,
The index value that gets displayed when one writes
<ol>
<li> something</li>
<li> anotherthing</li>
</ol>

should display as
1. something
2. anotherthing

If I programatically insert an LI between 1 and 2, I expected
1. something
2. inserted
3. anotherthing

but I seem to always see li.value as 0

Garadon · 11-12-2004, 05:19 PM

I am sure this could be done simpler wouldn't be surprised, but the following code can be used to return the index of an element 0 indexed.

Code:

<script>
function index(){
var child=this.previousSibling;
i=0;
while(child!=null){child=child.previousSibling;i++}
return i;
}
function test(){
ele=document.getElementById('t');
ele.index=index;
alert(ele.index());
}
Object.prototype.index=index;
</script>
<body onload="test();">
  <ol>
	  <li>tt</li>
	  <li id="t">tt</li>			
	  <li>tt</li>	
	  <li>tt</li>				
	</ol>
	<img>
	<a></a>
</body>

thanks to firefox I had to change the index function to this

Code:

function index(){
var child=this;
i=0;
while(child!=null){   
  child=child.previousSibling;i++;
	if(child==null)break;
  while(child.nodeName=='#text'){child=child.previousSibling;if(child==null)break;};
}
return i-1;
}

wac · 11-12-2004, 05:45 PM

(sigh

), it looks like inserting an LI doesn't cause renumbering using either <LI value=''<%=n%>' > or <OL start='0' > when an item is inserted or deleted, so I'll have to use Garadons method.
Oh well, the pitfalls of DHTML.

codegoboom · 11-12-2004, 06:05 PM

The list should be renumbered. What method are you using?

wac · 11-12-2004, 06:15 PM

sorry I can't provide the entire code in context
but this is the basics. After the insertBefore,
when I check .value of each element, I get 0 for everything
if I use <ol start='0'>, or I get the original values, if I put a
value tag on each LI. I get no reordering.

Is this another one of those stupid IE tricks? I'm using (and stuck with)
IE 6+

Code:

		
          var row = document.createElement('LI') ;
		row.id = id ;
		row.className = 'flow' ;
		row.style.width = width ;
		
		row.innerHTML = newtable ;  
		
	var idx = 0 ;
		try
		{
		var children = parent.getElementsByTagName('LI') ;
			idx = parseInt(event.getAttributeValue('index')) -1 ;
			parent.insertBefore(row, children[idx]) ;
		}
		catch (err)
		{
			idx = 0 ;
			parent.insertBefore(row, parent.firstChild) ;
		}

codegoboom · 11-12-2004, 07:50 PM

That's what the value attribute is for; it overrides auto-ordering. The list will be reordered correctly if you omit the attributes, or reassign all of them.