XPath expression to select all XML child nodes except a specific list?_问答_开发者

XPath expression to select all XML child nodes except a specific list?

开发者 https://www.devze.com 2022-12-12 22:30 出处：网络

Here\'s the sample data: <catalog> <cd> <title>Empire Burlesque</title> <artist>Bob Dylan</artist>

相关专题：xslt

Here's the sample data:

<catalog>
    <cd>
        <title>Empire Burlesque</title>
        <artist>Bob Dylan</artist>
        <country>USA</country>
                <customField1>Whatever</customField1>
                <customField2>Whatever</customField2>
                <customField3>Whatever</customField3>
        <company>Columbia</company>
        <price>10.90</price>
        <year>1985</year>
    </cd>
    <cd>
        <title>Hide your heart</title>
        <artist>Bonnie Tyler</artist>
        <country>UK</country>
                <customField1>Whatever</customField1>
                <customField2>Whatever</customField2>
        <company>CBS Records</company>
        <price>9.90</price>
        <year>1988</year>
    </cd>
    <cd>
        <title>Greatest Hits</title>
        <artist>Dolly Parton</artist>
        <country>USA</country>
                <customField1>Whatever</customField1>
        <company>RCA</company>
        <price>9.90</price>
        <year>1982</year>
    </cd>
</catalog>

Say I want to select everything except the price and year elements. I would expect to write something like the below, which obviously doesn't work.

<?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>
  <xsl:for-each select="//cd/* except (//cd/price|//cd/year)"开发者_运维问答>
    Current node: <xsl:value-of select="current()"/>
    <br />
  </xsl:for-each>
  </body>
  </html>
</xsl:template>
</xsl:stylesheet>

Please help me find a way to exclude certain child elements.

<xsl:for-each select="//cd/*[not(self::price or self::year)]">

But actually this is bad and unnecessarily complicated. Better:

<xsl:template match="catalog">
  <html>
    <body>
      <xsl:apply-templates select="cd/*" />
    </body>
  </html>
</xsl:template>

<!-- this is an empty template to mute any unwanted elements -->
<xsl:template match="cd/price | cd/year" />

<!-- this is to output wanted elements -->
<xsl:template match="cd/*">
  <xsl:text>Current node: </xsl:text>
  <xsl:value-of select="."/>
  <br />
</xsl:template>

Avoid <xsl:for-each>. Almost all of the time it is the wrong tool and should be substituted by <xsl:apply-templates> and <xsl:template>.

The above works because of match expression specificity. match="cd/price | cd/year" is more specific than match="cd/*", so it is the preferred template for cd/price or cd/year elements. Don't try to exclude nodes, let them come and handle them by discarding them.

I'd start experimenting with something like

"//cd/*[(name() != 'price') and (name() != 'year')]"

Or you just do normal recursive template matching with <xsl:apply-templates/>, and then have empty templates for <price/> and <year/> elements:

<xsl:template match="price"/>
<xsl:template match="year"/>

XPath expression to select all XML child nodes except a specific list?

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