[SOLVED] XSL: Count levels between current node and another specific node

XSL: Count levels between current node and another specific node

I have following XML structure:

<someSubNodeInXmlFile text="mainListStart">
    <a text="text1">
        <b text="text2">
            <a text="text3">
                <c text=""text4/>
            </a>
            <a text="text5"/>
        </b>
    </a>
    <a text="text6">
        <c text="text7"/>
    </a>
</someSubNodeInXmlFile>

My problem is about numbering. The above XML can be seen as a nested list.

The default format for the numbering is '1.1.1 ', level="multiple". But if the list is nested for the 4th time or more, the format should change to '1', level="single".

The desired output for the above structure would be:

1. mainListStart
    1.1 text1
        1.1.1 text2
            1   text3
                1   text4
            2   text5
    1.2 text6
        1.2.1 text7

In my opinion e.g. if my current node is the first I need to calculate how many ancestors are between my current node and the parent . If the calculated number is lower than 4, use '1.1.1 ' as list-item format, otherwise use '1' as format.

I tried several things now, but none of them worked. I am able to calculate how many ancestors in general I have for the current node, but this is calculating the complete ancestor tree, and not until the specific node 'someSubNodeInXmlFile'.

Is this possible with a simple xpath expression or do I try to calculate the number with a recursive template that starts from current() and looks for each next ancestor if it's desired one, adding one to a number if not and proceed to the next ancestor?

I can imagine that the latter idea is not very performant (if it works at all). But what's the best solution?

Thanks in advance.

BRgrds, Jens

Solution

If you know hot to get the number of all the ancestors of a node, then just subtract the number of the ancestors of someSubNodeInXmlFile and you have the number of the nodes in between (plus one).

R---o---o---X---o---o---o---o---o---N
            3                       9
            \_______________________/
                  9 - 3 - 1 = 5