Re: Best way to represent an item and its context?

Michael Kay
Saxonica

Hi Folks,

Consider this XML document:

<?xml version="1.0"?>
<Book>
       <title>GML</title>
       <author>Ron Lake</author>
       <date>2004</date>
</Book>

Suppose that while processing that XML document I get to the author element:

<author>Ron Lake</author>

I want to store this element and its context in a variable. The context of author is the entire document.

So I want a function that takes as input the author element and the Book element and returns a representation of the element and its context:

item-in-context :: Item -> Context -> Item-in-Context

Read as: "The function item-in-context has two arguments -- an item (element) and a context -- and it returns a representation of the element and its context."

Here I invoke that function and store the result into a variable:

<xsl:template match="/">

<xsl:variable name="v1" select="f:item-in-context(Book/author, Book)" />

</xsl:template>

I have various functions which operate on that Item-in-Context variable. For example, one function returns the item's parent:

parent :: Item-in-Context -> Item

Here I invoke the parent function and store the result into a second variable:

<xsl:template match="/">

<xsl:variable name="v1" select="f:item-in-context(Book/author, Book)" />

<xsl:variable name="v2" select="f:parent($v1)" />

</xsl:template>

What's the best way to represent an item and its context?

/Roger