XML Tutorial/XPath/attribute
Версия от 18:22, 25 мая 2010; (обсуждение)
Содержание
- 1 Attributes can be accessed in similar way as elements
- 2 Attributes can be processed in the same way as elements
- 3 Check attribute existance
- 4 Check value of attribute
- 5 for-each select="attribute::*"
- 6 If the element has an attribute
- 7 includes or excludes elements if the specified attribute is present
- 8 Select elements, which contain or do not contain the given attribute
- 9 select="state/@joined"
Attributes can be accessed in similar way as elements
"@" is in the front of attribute names.
"@name" matches name attribute of an element.
"data/@color" matches color attribute of data element.
File: Data.xml
<?xml version="1.0"?>
<dog name="Joe">
<data weight="18 kg" color="black"/>
</dog>
File: Transform.xslt
<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="dog">
<paragraph>
<b>
<xsl:text>Dog: </xsl:text>
</b>
<xsl:value-of select="@name"/>
</paragraph>
<paragraph>
<b>
<xsl:text>Color: </xsl:text>
</b>
<xsl:value-of select="data/@color"/>
</paragraph>
</xsl:template>
</xsl:stylesheet>
Output:
<?xml version="1.0" encoding="UTF-8"?><paragraph><b>Dog: </b>Joe</paragraph><paragraph><b>Color: </b>black</paragraph>
Attributes can be processed in the same way as elements
File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<employee id="js0034">
Joe Smith
</employee>
File: Transform.xslt
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="employee">
<xsl:value-of select="."/>
<xsl:text>[</xsl:text>
<xsl:apply-templates select="@id"/>
<xsl:text>]</xsl:text>
</xsl:template>
<xsl:template match="@id">
<b>
<i>
<xsl:value-of select="."/>
</i>
</b>
</xsl:template>
</xsl:stylesheet>
Output:
<?xml version="1.0" encoding="UTF-8"?>
Joe Smith
[<b><i>js0034</i></b>]
Check attribute existance
File: Data.xml
<?xml version="1.0" standalone="yes"?>
<poem author="jm" year="1667">
<verse>line 1</verse>
<verse>line 2</verse>
<verse>line 3</verse>
<verse>line 4</verse>
</poem>
File: Transform.xslt
<?xml version="1.0" standalone="yes"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output method="text" />
<xsl:template match="poem">
<xsl:if test="@author="jm"">1. The poem"s author is jm.</xsl:if>
</xsl:template>
</xsl:stylesheet>
Output:
1. The poem"s author is jm.
Check value of attribute
File: Data.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="Transform.xslt"?>
<advertisement action="create">
asdf
</advertisement>
File: Transform.xslt
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output method="text" indent="no" />
<xsl:variable select="advertisement/text" name="path" />
<xsl:template match="/">
<xsl:apply-templates select="$path" />
</xsl:template>
<xsl:template match="text">
<xsl:apply-templates />
</xsl:template>
<xsl:template match="headline">
<xsl:text>\F4</xsl:text>
<xsl:value-of select="text()" />
</xsl:template>
<xsl:template match="para">
<xsl:if test="self::para[@fontsize="agate"]">
<xsl:text> \F1</xsl:text>
<xsl:value-of select="text()" />
</xsl:if>
<xsl:if test="self::para[@justify="flushleft"]">
<xsl:text><</xsl:text>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
for-each select="attribute::*"
File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<data>
<AAA id="a1" pos="start">
<BBB id="b1"/>
<BBB id="b2"/>
</AAA>
<AAA id="a2">
<BBB id="b3"/>
<BBB id="b4"/>
<CCC id="c1">
<CCC id="c2"/>
</CCC>
<BBB id="b5">
<CCC id="c3"/>
</BBB>
</AAA>
</data>
File: Transform.xslt
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<table border="1" cellpadding="6">
<tr>
<td colspan="2">Axis: attribute</td>
</tr>
<tr>
<td>Element</td>
<td>Node-set</td>
</tr>
<xsl:for-each select="/source//*">
<xsl:call-template name="print"/>
</xsl:for-each>
</table>
</xsl:template>
<xsl:template name="print">
<tr>
<td>
<xsl:value-of select="name()"/>
<xsl:text> id = </xsl:text>
<xsl:value-of select="./@id"/>
</td>
<td>
<xsl:for-each select="attribute::*">
<xsl:if test="not(@id)">
<xsl:value-of select="name()"/>
</xsl:if>
<xsl:value-of select="./@id"/>
<xsl:text/>
</xsl:for-each>
</td>
</tr>
</xsl:template>
</xsl:stylesheet>
Output:
<?xml version="1.0" encoding="UTF-8"?><table border="1" cellpadding="6"><tr><th colspan="2">Axis: attribute</th></tr><tr><td>Element</th><td>Node-set</th></tr></table>
If the element has an attribute
File: Data.xml
<?xml version="1.0" standalone="yes"?>
<poem author="jm" year="1667">
<verse>line 1</verse>
<verse>line 2</verse>
<verse>line 3</verse>
<verse>line 4</verse>
</poem>
File: Transform.xslt
<?xml version="1.0" standalone="yes"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output method="text" />
<xsl:template match="poem">
<xsl:if test="@author">
The poem has an author attribute.
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Output:
The poem has an author attribute.
includes or excludes elements if the specified attribute is present
File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<data>
<car id="a234" checked="yes"/>
<car id="a111" checked="yes"/>
<car id="a005"/>
</data>
File: Transform.xslt
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="car[not(@checked)]">
<paragraph>
<xsl:text>Car: </xsl:text>
<xsl:value-of select="@id"/>
</paragraph>
</xsl:template>
</xsl:stylesheet>
Output:
<?xml version="1.0" encoding="UTF-8"?>
<paragraph>Car: a005</paragraph>
Select elements, which contain or do not contain the given attribute
File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<data>
<car id="a234" checked="yes"/>
<car id="a111" checked="yes"/>
<car id="a005"/>
</data>
File: Transform.xslt
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="car[@checked]">
<paragraph>
<xsl:text>Car: </xsl:text>
<xsl:value-of select="@id"/>
</paragraph>
</xsl:template>
</xsl:stylesheet>
Output:
<?xml version="1.0" encoding="UTF-8"?>
<paragraph>Car: a234</paragraph>
<paragraph>Car: a111</paragraph>
select="state/@joined"
File: Data.xml
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="Transform.xslt" type="text/xsl"?>
<member>
<state joined="1995">Austria</state>
<state joined="1950">Belgium</state>
<state joined="1973">Denmark</state>
<state joined="1995">Finland</state>
<state joined="1950">France</state>
</member>
File: Transform.xslt
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" />
<xsl:template match="member">
<xsl:text>Number of EU Member States: </xsl:text>
<xsl:value-of select="count(state)" />
<xsl:text> </xsl:text>
<xsl:apply-templates select="state/@joined">
<xsl:sort data-type="number" />
</xsl:apply-templates>
<xsl:text> </xsl:text>
</xsl:template>
<xsl:template match="state/@joined">
<xsl:text> - </xsl:text>
<xsl:apply-templates select=".." />
<xsl:text> (</xsl:text>
<xsl:value-of select="." />
<xsl:text>) </xsl:text>
</xsl:template>
</xsl:stylesheet>
Output:
Number of EU Member States: 5
- Belgium (1950)
- France (1950)
- Denmark (1973)
- Austria (1995)
- Finland (1995)