Don't understand how XSLT works

metinhoclam · July 31st, 2010, 12:47 PM

I have the source document:
<?xml version="1.0" encoding="ISO-8859-1"?>

<catalog>
<cd>
<title>Empire Burlesque</title>
<artist>Bob Dylan</artist>
<country>USA</country>
<company>Columbia</company>
<price>10.90</price>
<year>1985</year>
</cd>

<cd>
<title>Still got the blues</title>
<artist>Gary Moore</artist>
<country>UK</country>
<company>Virgin records</company>
<price>10.20</price>
<year>1990</year>
</cd>

<cd>
<title>One night only</title>
<artist>Bee Gees</artist>
<country>UK</country>
<company>Polydor</company>
<price>10.90</price>
<year>1998</year>
</cd>
<cd>
<title>Sylvias Mother</title>
<artist>Dr.Hook</artist>
<country>UK</country>
<company>CBS</company>
<price>8.10</price>
<year>1973</year>
</cd>
<cd>
<title>Maggie May</title>
<artist>Rod Stewart</artist>
<country>UK</country>
<company>Pickwick</company>
<price>8.50</price>
<year>1993</year>
</cd>

<cd>
<title>For the good times</title>
<artist>Kenny Rogers</artist>
<country>UK</country>
<company>Mucik Master</company>
<price>8.70</price>
<year>1995</year>
</cd>

<cd>
<title>Soulsville</title>
<artist>Jorn Hoel</artist>
<country>Norway</country>
<company>WEA</company>
<price>7.90</price>
<year>1996</year>
</cd>
<cd>
<title>Bridge of Spies</title>
<artist>T`Pau</artist>
<country>UK</country>
<company>Siren</company>
<price>7.90</price>
<year>1987</year>
</cd>

<cd>
<title>Midt om natten</title>
<artist>Kim Larsen</artist>
<country>EU</country>
<company>Medley</company>
<price>7.80</price>
<year>1983</year>
</cd>
<cd>
<title>Pavarotti Gala Concert</title>
<artist>Luciano Pavarotti</artist>
<country>UK</country>
<company>DECCA</company>
<price>9.90</price>
<year>1991</year>
</cd>
<cd>
<title>The dock of the bay</title>
<artist>Otis Redding</artist>
<country>USA</country>
<company>Atlantic</company>
<price>7.90</price>
<year>1987</year>
</cd>

</catalog>
---
And my transformation file like this:
----
<?xml version="1.0" encoding="ISO-8859-1"?>

<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<html>
<body>
<h2>My CD Collection</h2>
<xsl:call-template name="artist"/>
<xsl:call-template name="below18"/>

</body>
</html>
</xsl:template>

<xsl:template name="artist" >
<ArtistUK>
<xsl:for-each select="catalog/cd/artist">
<xsl:if test="catalog/cd/country='UK'">
<list_artist><xsl:value-of select ="artist"/></list_artist>
</xsl:if>
</xsl:for-each>
</ArtistUK>
</xsl:template>



<xsl:template name="below18" >
<Artistbelow18>
<xsl:for-each select="catalog/cd/artist">
<xsl:if test="catalog/cd/year > 1992 and catalog/cd/country='UK'">
<list_artist><xsl:value-of select ="artist"/></list_artist>
</xsl:if>
</xsl:for-each>
</Artistbelow18>
</xsl:template>
</xsl:stylesheet>
----
The expectation document is: receive the information about 2 list of artists (that is in upper each template)

Martin Honnen · July 31st, 2010, 12:54 PM

I think instead of

Code:

<xsl:for-each select="catalog/cd/artist">
<xsl:if test="catalog/cd/country='UK'">
<list_artist><xsl:value-of select ="artist"/></list_artist>
</xsl:if>
</xsl:for-each>

you rather want

Code:

<xsl:for-each select="catalog/cd[country='UK']/artist">
   <list_artist><xsl:value-of select ="."/></list_artist>
</xsl:for-each>

although using an element like 'list_artist' in HTML (which your first template outputs) does not make much sense. But at least the code above shows you how to put a predicate in square brackets and it should correctly output artist names.

mhkay · July 31st, 2010, 02:51 PM

You need to read about the concept of the "context node" or "context item" which represent the current position in the document. An instruction like xsl:for-each changes the context node. Relative path expressions navigate starting at the context node. So you don't want to say

Code:

<xsl:for-each select="catalog/cd/artist">
<xsl:if test="catalog/cd/country='UK'">

you should say instead

Code:

<xsl:for-each select="catalog/cd/artist">
<xsl:if test="../country='UK'">

or in this case, since the condition applies to the whole body of the for loop, you can simply select the cd's you want with a predicate select="catalog/cd[country='uk']/artist".