我正在研究一个项目并遇到问题。 我最近确定一个人不能改变变量值，似乎无法找到解决这个问题的方法。我需要创建通用的代码，我无法做到这一点。
我的XSLT代码 .........
<tracklist>
<xsl:for-each select = "VinylRecord/Tracks/Song">
<xsl:choose>
<xsl:when test = "@Track = 1">
<xsl:element name="side{@Side}">
<xsl:variable name = "d" select = "@Track"/>
<xsl:for-each select = "../Song">
<xsl:choose>
<xsl:when test = "@Side = ../Song/following:: @Side">
<track>
<xsl:attribute name = "no">
<xsl:value-of select = "@Track" />
</xsl:attribute>
<xsl:attribute name = "runtime">
<xsl:value-of select = "Length" />
</xsl:attribute>
<xsl:value-of select = "text()" />
</track>
</xsl:when>
</xsl:choose>
</xsl:for-each>
</xsl:element>
</xsl:when>
</xsl:choose>
</xsl:for-each>
</tracklist>
XML文档 ............
<Tracks>
<Song Side="A" Track="1">
The Nerve
<Length>2.58</Length>
</Song>
<Song Side="A" Track="2">
Backfire
<Length>3.22</Length>
</Song>
<Song Side="A" Track="3">
Clipping
<Length>4.05</Length>
</Song>
<Song Side="A" Track="4">
Spotlight
<Length>3.21</Length>
</Song>
<Song Side="A" Track="5">
No Response
<Length>4.01</Length>
</Song>
<Song Side="A" Track="6">
Pins and Needles
<Length>4.05</Length>
</Song>
<Song Side="B" Track="1">
Goodbye
<Length>4.09</Length>
</Song>
<Song Side="B" Track="2">
Odds
<Length>3.01</Length>
</Song>
<Song Side="B" Track="3">
Electrify
<Length>3.49</Length>
</Song>
<Song Side="B" Track="4">
Armistice
<Length>3.54</Length>
</Song>
<Song Side="B" Track="5">
Lost Year
<Length>3.13</Length>
</Song>
<Song Side="B" Track="6">
Burden
<Length>9.06</Length>
</Song>
</Tracks>
...
任何提示都将非常感谢
预期结果 ...............
这只是上面显示的整个程序的片段，但结果假设显示为：
<tracklist>
<sideA>
<track no="1" runtime="2.58">The Nerve</track>
<track no="2" runtime="3.22">Backfire</track>
<track no="3" runtime="4.05">Clipping</track>
<track no="4" runtime="3.21">Spotlight</track>
<track no="5" runtime="4.01">No Response</track>
<track no="6" runtime="4.05">Pins and Needles</track>
</sideA>
<sideB>
<track no="1" runtime="4.09">Goodbye</track>
<track no="2" runtime="3.01">Odds</track>
<track no="3" runtime="3.49">Electrify</track>
<track no="4" runtime="3.54">Armistice</track>
<track no="5" runtime="3.13">Lost Year</track>
<track no="6" runtime="9.06">Burden</track>
</sideB>
</tracklist>
答案 0 :(得分：0)
“这不是一个错误，它是一个功能”：XSLT变量的设计是不可更改的。实际上它们可以被命名为常量。解决这个问题很困难，可以使用参数来完成。在大多数情况下，如果使用XSLT编程尝试，则不需要，其中程序由数据通过模板驱动。像“for-each”这样的事情是程序性的方式，并不真正适合XSLT的想法。你想得到什么结果呢？
在知道预期结果后，sylesheet应如下所示：
<xsl:template match="Tracks">
<tracklist>
<sideA>
<xsl:apply-templates select="Song[@Side='A']"/>
</sideA>
<sideB>
<xsl:apply-templates select="Song[@Side='B']"/>
</sideB>
</tracklist>
</xsl:template>
<xsl:template match="Song">
<track no="{@Track}" runtime="{Length}">
<xsl:value-of select="text()"/>
</track>
</xsl:template>
答案 1 :(得分：0)
它看起来像是一个标准的分组问题。
如果您使用的是XSLT 2.0，那么
<xsl:for-each-group select="Song" group-by="Side">
<xsl:element name="Side{current-grouping-key)}">
<xsl:for-each select="current-group()">
<track no="{position()}" runtime="{Length}">
<xsl:value-of select="."/>
</track>
</xsl:for-each>
</xsl:element>
</xsl:for-each-group>
使用XSLT 1.0它会更加困难，但仍然是教科书问题：查找“Muenchian Grouping”的答案。
答案 2 :(得分：0)
此XSLT解决方案非常简单：
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:key name="kFollowing" match="Song"
use="generate-id(preceding-sibling::Song[not(@Side = current()/@Side)][1])"/>
<xsl:template match="node()|@*">
<xsl:copy>
<xsl:apply-templates select="node()|@*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="/*">
<tracklist>
<xsl:apply-templates/>
</tracklist>
</xsl:template>
<xsl:template match="Song"/>
<xsl:template match=
"Song[not(@Side = preceding-sibling::Song[1]/@Side)]">
<xsl:element name="side{@Side}">
<xsl:apply-templates mode="inGroup" select=
"key('kFollowing', generate-id(preceding-sibling::Song[1]/@side))"/>
</xsl:element>
</xsl:template>
<xsl:template match="Song" mode="inGroup">
<track no="{@Track}" runtime="{Length}"><xsl:value-of select="text()"/></track>
</xsl:template>
<xsl:template match="text()"/>
</xsl:stylesheet>
应用于提供的XML文档：
<Tracks>
<Song Side="A" Track="1">
The Nerve
<Length>2.58</Length>
</Song>
<Song Side="A" Track="2">
Backfire
<Length>3.22</Length>
</Song>
<Song Side="A" Track="3">
Clipping
<Length>4.05</Length>
</Song>
<Song Side="A" Track="4">
Spotlight
<Length>3.21</Length>
</Song>
<Song Side="A" Track="5">
No Response
<Length>4.01</Length>
</Song>
<Song Side="A" Track="6">
Pins and Needles
<Length>4.05</Length>
</Song>
<Song Side="B" Track="1">
Goodbye
<Length>4.09</Length>
</Song>
<Song Side="B" Track="2">
Odds
<Length>3.01</Length>
</Song>
<Song Side="B" Track="3">
Electrify
<Length>3.49</Length>
</Song>
<Song Side="B" Track="4">
Armistice
<Length>3.54</Length>
</Song>
<Song Side="B" Track="5">
Lost Year
<Length>3.13</Length>
</Song>
<Song Side="B" Track="6">
Burden
<Length>9.06</Length>
</Song>
</Tracks>
产生了想要的正确结果：
<tracklist>
<sideA>
<track no="1" runtime="2.58">
The Nerve
</track>
<track no="2" runtime="3.22">
Backfire
</track>
<track no="3" runtime="4.05">
Clipping
</track>
<track no="4" runtime="3.21">
Spotlight
</track>
<track no="5" runtime="4.01">
No Response
</track>
<track no="6" runtime="4.05">
Pins and Needles
</track>
</sideA>
<sideB>
<track no="1" runtime="2.58">
The Nerve
</track>
<track no="2" runtime="3.22">
Backfire
</track>
<track no="3" runtime="4.05">
Clipping
</track>
<track no="4" runtime="3.21">
Spotlight
</track>
<track no="5" runtime="4.01">
No Response
</track>
<track no="6" runtime="4.05">
Pins and Needles
</track>
</sideB>
</tracklist>