如何从标记存储在变量中的树中选择节点? [英] How can I select nodes from a tree whose markup is stored in a variable?

问题描述

考虑以下 XSLT 脚本:

Consider the following XSLT script:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:output method="text" encoding="iso-8859-1"/>

<xsl:variable name="stringmap">
<map>
<entry><key>red</key><value>rot</value></entry>
<entry><key>green</key><value>gruen</value></entry>
<entry><key>blue</key><value>blau</value></entry>
</map>
</xsl:variable>

<xsl:template match="/">
<!-- IMPLEMENT ME -->
</xsl:template>

</xsl:stylesheet>

我希望这个脚本打印redgreenblue.

有什么方法可以将存储在 stringmap 变量中的 XML 标记视为自己的文档，我可以在其上运行 XPath 查询?我基本上是在寻找类似的东西

Is there any way to treat the XML markup which is stored in the stringmap variable as a document of its own which I can run XPath queries on? I'm basically looking for something like

<xsl:for-each select="document($stringmap)/map/entry">
    <xsl:value-of select="key"/>
</xsl:for-each>

(除了 document() 函数需要一个 URI).

(except that the document() function expects an URI).

动机:我有各种长 元素将给定的字符串映射到另一个字符串.我想用一个带有map"参数(这是一个简单的 XML 文档)的模板替换所有这些.我希望然后我可以用一个简单的语句替换 <xsl:choose> 像 <xsl:value-of select="$stringmap/map/entry/value[../key='$givenkey']"/>

Motivation: I have various long <xsl:choose> elements which map a given string to another string. I'd like to replace all those with a single template which takes a 'map' argument (which is a simple XML document). My hope is that I can then replace the <xsl:choose> with a simple statement like <xsl:value-of select="$stringmap/map/entry/value[../key='$givenkey']"/>

我通过 xsltproc 使用 XSLT 1.0.

I'm using XSLT 1.0 using xsltproc.

推荐答案

你几乎是对的，使用 document('') 将允许你处理当前样式表中的节点集:

You're almost right, using document('') will allow you to process node sets inside the current stylesheet:

<xsl:for-each select="document('')/xsl:stylesheet/xsl:variable[@name='stringmap']/map/entry">
    <xsl:value-of select="key"/>
</xsl:for-each>

在这种情况下，不必将 map 节点集定义为变量:

It's not necessary to define the map node set as a variable in this case:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet xmlns:data="some.uri" version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <data:map>
    <entry><key>red</key><value>rot</value></entry>
    <entry><key>green</key><value>gruen</value></entry>
    <entry><key>blue</key><value>blau</value></entry>
  </data:map>

  <xsl:template match="/">
    <xsl:for-each select="document('')/xsl:stylesheet/data:map/entry">
      <xsl:value-of select="key"/>
    </xsl:for-each>
  </xsl:template>

</xsl:stylesheet>

如果您不使用 xsl:variable 作为包装器，您必须记住顶级元素必须具有非空的命名空间 URI.

If you do not use xsl:variable as a wrapper, you must remember that a top level elements must have a non null namespace URI.

在 XSLT 2.0 中，可以只迭代变量中的内容:

In XSLT 2.0 it would've been possible to just iterate over the content in a variable:

<xsl:variable name="map">
  <entry><key>red</key><value>rot</value></entry>
  <entry><key>green</key><value>gruen</value></entry>
  <entry><key>blue</key><value>blau</value></entry>
</xsl:variable>

<xsl:template match="/">
  <xsl:for-each select="$map/entry">
    <xsl:value-of select="key"/>
  </xsl:for-each>
</xsl:template>

这篇关于如何从标记存储在变量中的树中选择节点?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！