我了解XPath语法是如何工作的,并且可以编写XPath命令从XML文件中提取某些信息。
我希望将XPath命令转换为XSLT脚本,以便其他人可以在XML文件上运行脚本以获得相同的输出。
。
我有一个XML文件,我们说,看起来像这样:
<?xml version="1.0" encoding="UTF-8"?>
<library>
<section id="109196796">
<master_information>
<shelf_identifier>
<identifier type="CodeX" type_id="2">LB1500605917</identifier>
<identifier type="Common Code" type_id="15">150060591</identifier>
</shelf_identifier>
<shelf_master>
<section_type>1</section_type>
<book_type>3</book_type>
</shelf_master>
</master_information>
</section>
<section id="109196798">
<master_information>
<shelf_identifier>
<identifier type="CodeX" type_id="2">LB0777775917</identifier>
<identifier type="Common Code" type_id="15">077777591</identifier>
</shelf_identifier>
<shelf_master>
<section_type>1</section_type>
<book_type>3</book_type>
</shelf_master>
</master_information>
</section>
<section id="109196800">
<master_information>
<shelf_identifier>
<identifier type="CodeX" type_id="2">LB2589165917</identifier>
<identifier type="Common Code" type_id="15">258916591</identifier>
</shelf_identifier>
<shelf_master>
<section_type>1</section_type>
<book_type>3</book_type>
</shelf_master>
</master_information>
</section>
</library>
如果我运行下面的XPath命令,
//identifier[@type='CodeX']
我得到了输出:
LB1500605917
LB0777775917
LB2589165917
. .这是意料之中的。现在,我尝试将XPath命令转换为XSL语法,如下所示:
<?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"/>
<xsl:variable name="return">
<xsl:text>
</xsl:text> <!-- defined a line break -->
</xsl:variable>
<xsl:template match="//library"></xsl:template>
<xsl:template match="//section/master_information/shelf_identifier/identifier">
<xsl:value-of select="@type='CodeX'"/>
<xsl:value-of select="$return"/> <!-- this basically puts a line break -->
</xsl:template>
</xsl:stylesheet>
XSL似乎是正确的。但是,不会生成任何输出。
我是XSL/XSLT的新手。我做错了什么?
您可以做的是添加一个与xpath相同节点匹配的模板,然后输出值和换行符…
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<!--The strip-space isn't completely necessary. I just always include it in my
default stylesheets. It strips whitespace. You can preserve whitespace with
xsl:preserve-space. See https://www.w3.org/TR/xslt#strip for more details.-->
<xsl:strip-space elements="*"/>
<!--Suppress output of text nodes by built-in templates.-->
<xsl:template match="text()"/>
<!--Match "indentifier" elements that contain a "type" attribute
with the value of "CodeX".-->
<xsl:template match="identifier[@type='CodeX']">
<!--Output the value of the current context ("identifier") concatenated with
a newline. ("
" is a hex entity reference. You could also use a decimal
reference (" ")). You could use either of these references as the value
of a variable too (or even declare it as an entity).
I use normalize-space() instead of . to clean up any additional spaces.
See https://www.w3.org/TR/xpath/#function-normalize-space for details.-->
<xsl:value-of select="concat(normalize-space(),'
')"/>
</xsl:template>
</xsl:stylesheet>
注意与text()
匹配的空模板。添加这一点是为了通过XSLT的内置模板规则抑制text()节点的输出。
还请注意,我没有在我的匹配中使用//
。这也是因为内置规则;默认情况下,它们允许递归处理。
你为什么不干脆:
XSLT 1.0<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" encoding="UTF-8"/>
<xsl:template match="/">
<xsl:for-each select="//identifier[@type='CodeX']">
<xsl:value-of select="."/>
<xsl:text> </xsl:text>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>