depth of inheritance tree

mejias · February 7th, 2011, 04:04 PM

Hi

How can get the depth of inheritance tree?

I have a xml like this:

<class><name>ColumnX</name>

<super><name>Static</name></super>

</class>
<class><name>ColumnY</name>

<super><name>ColumnX</name></super>

</class>
<class><name>ColumnZ</name>

<super><name>ColumnY</name></super>

</class>
<class><name>ColumnW</name>

<super><name>Static</name></super>

</class>

I'm working a xsl like this:

<xsl:template match="//class">
<xsl:apply-templates select="//*[name()='super' and super/name = class/name]"/>
</xsl:template>

But, is this is a disaster. I do not know how to get the highest level of inheritance depth of an XML tree as above.

Any ideas?

mhkay · February 7th, 2011, 06:49 PM

I would start by building the tree as an XML tree, and then find the maximum depth. (Presumably you want the tree for other reasons as well.) By the "XML tree" I mean one where the parent-child relationship in the tree represents the superclass-subclass relationship in the data. Assuming you know what the root node is, building the tree is not difficult: it's essentially

Code:

<xsl:template match="class">
  <class name="{name}">
    <xsl:apply-templates select="//class[super/name=current()/name]"/>
  </class>
</xsl:template>

Then the maximum depth in this tree is max(//class/count(ancestor::*)).

mejias · February 7th, 2011, 08:19 PM

My xslt do not support max function!!

Is there another way to do it?

Thanks.

mhkay · February 8th, 2011, 05:02 AM

If you're constrained to use XSLT 1.0 then it's a good idea to say so, since it avoids wasting people's time (usually I leave XSLT 1.0 questions to someone else since it's so long since I used it, and since the answers are often so convoluted).

Generally the way to compute max() in XSLT 1.0 is to sort into descending order, and then take the first. Essentially

Code:

<xsl:for-each select="//*">
  <xsl:sort select="count(ancestor::*)" data-type="number" order="descending"/>
  <xsl:if test="position() = 1">
    <xsl:value-of select="count(ancestor::*)"/>
  </xsl:if>
</xsl:for-each>