XSLT link between two elements that share the same value and print the linked data

Question

I've started learning xml/xslt and xsl-fo and while doing some basic exercises I've got myself into a small issue.

I am trying to link the books to their category price using <category> and <priceCategory> . Not sure what to search for, while browsing stackoverflow I found that I can use a key, like this.

<xsl:key name="link" match="priceCategory" use="priceCategory"/>

and print the value using

<xsl:for-each select="bookstore/books/mybook">
<xsl:value-of select="name"/>
<xsl:value-of select="key('link', money/prices/price)/priceCategory"/>
</xsl:for-each>

But I had no success so far, anyone can help me with some documentation or an example/explanation, I think I am not searching for the right thing, I can't find the right word for this type of problem.

This is an example XML:

<bookstore>
      <books>
            <mybook>
                  <name>bookname1</name>
                  <pages>350</pages>
                  <category>A</category>
            </book>
            <mybook>
                  <name>bookname2</name>
                  <pages>150</pages>
                  <category>B</category>
            </book>
            <mybook>
                  <name>bookname3</name>
                  <pages>450</pages>
                  <category>B</category>
            </book>
            <mybook>
                  <name>bookname4</name>
                  <pages>550</pages>
                  <category>C</category>
            </book>
      <books>
      <money>
            <prices>
                  <price>50</price>
                  <priceCategory> A </priceCategory>
            </prices>
            <prices>
                  <price>100</price>
                   <priceCategory> B </priceCategory>                  
            </prices>
            <prices>
                  <price>150</price>
                  <priceCategory> C </priceCategory>                 
            </prices>
      </money>
</bookstore>

Thank you :)

Answer 1

I suppose you want to show the price of the category? If yes, you could use this:

<xsl:key name="link" match="prices" use="priceCategory"/>

This key wil match on prices using priceCategory when calling the key as "filter" .

<xsl:for-each select="bookstore/books/mybook">
<xsl:value-of select="name"/>
<xsl:value-of select="key('link', category)/price"/>
</xsl:for-each>