XPath谓词 _谓词

谓词指定用方括号括起来的XPath表达式。在某些情况下, 它用于限制节点集中的选定节点。请参见” 雇员” 示例中的谓词用法。
employee.xml

< ?xml version = "1.0"?> < ?xml-stylesheet type = "text/xsl" href = "http://www.srcmini.com/employee.xsl"?> < class> < employee id = "001"> < firstname> Abhiram< /firstname> < lastname> Kushwaha< /lastname> < nickname> Manoj< /nickname> < salary> 15000< /salary> < /employee> < employee id = "002"> < firstname> Akash< /firstname> < lastname> Singh< /lastname> < nickname> Bunty< /nickname> < salary> 25000< /salary> < /employee> < employee id = "003"> < firstname> Brijesh< /firstname> < lastname> Kaushik< /lastname> < nickname> Ballu< /nickname> < salary> 20000< /salary> < /employee> < employee id = "004"> < firstname> Zoya< /firstname> < lastname> Mansoori< /lastname> < nickname> Sonam< /nickname> < salary> 30000< /salary> < /employee> < /class>

Index	Predicate	Description
1)	/class/employee[1]	它将选择第一个employee元素, 它是class元素的子元素。
2)	/class/employee[last()]	它将选择为class元素的子元素的最后一个employee元素。
3)	/ class / employee [@id = 002]	它将选择id为002的员工元素。
4)	/ class / salary [salary> 10000]	它将选择薪金大于10000的员工元素。

XPath谓词示例让我们以一个示例为例, 通过遍历每个员工来创建一个< employee> 元素及其详细信息的表。本示例使用谓词计算雇员节点的位置, 然后打印雇员详细信息。
【XPath谓词】employee.xml

< ?xml version = "1.0"?> < ?xml-stylesheet type = "text/xsl" href = "http://www.srcmini.com/employee.xsl"?> < class> < employee id = "001"> < firstname> Abhiram< /firstname> < lastname> Kushwaha< /lastname> < nickname> Manoj< /nickname> < salary> 15000< /salary> < /employee> < employee id = "002"> < firstname> Akash< /firstname> < lastname> Singh< /lastname> < nickname> Bunty< /nickname> < salary> 25000< /salary> < /employee> < employee id = "003"> < firstname> Brijesh< /firstname> < lastname> Kaushik< /lastname> < nickname> Ballu< /nickname> < salary> 20000< /salary> < /employee> < employee id = "004"> < firstname> Zoya< /firstname> < lastname> Mansoori< /lastname> < nickname> Sonam< /nickname> < salary> 30000< /salary> < /employee> < /class>

员工.xsl

< ?xml version = "1.0" encoding = "UTF-8"?> < xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform"> < xsl:template match = "/"> < html> < body> < h2> Employee< /h2> < table border = "1"> < tr bgcolor = "pink"> < th> ID< /th> < th> First Name< /th> < th> Last Name< /th> < th> Nick Name< /th> < th> Salary< /th> < /tr> < xsl:for-each select = "/class/employee[1]"> < tr> < td> < xsl:value-of select = "@id"/> < /td> < td> < xsl:value-of select = "firstname"/> < /td> < td> < xsl:value-of select = "lastname"/> < /td> < td> < xsl:value-of select = "nickname"/> < /td> < td> < xsl:value-of select = "salary"/> < /td> < /tr> < /xsl:for-each> < xsl:for-each select = "/class/employee[last()]"> < tr> < td> < xsl:value-of select = "@id"/> < /td> < td> < xsl:value-of select = "firstname"/> < /td> < td> < xsl:value-of select = "lastname"/> < /td> < td> < xsl:value-of select = "nickname"/> < /td> < td> < xsl:value-of select = "salary"/> < /td> < /tr> < /xsl:for-each> < xsl:for-each select = "/class/employee[@id = 002]"> < tr> < td> < xsl:value-of select = "@id"/> < /td> < td> < xsl:value-of select = "firstname"/> < /td> < td> < xsl:value-of select = "lastname"/> < /td> < td> < xsl:value-of select = "nickname"/> < /td> < td> < xsl:value-of select = "salary"/> < /td> < /tr> < /xsl:for-each> < xsl:for-each select = "/class/employee[salary > 10000]"> < tr> < td> < xsl:value-of select = "@id"/> < /td> < td> < xsl:value-of select = "firstname"/> < /td> < td> < xsl:value-of select = "lastname"/> < /td> < td> < xsl:value-of select = "nickname"/> < /td> < td> < xsl:value-of select = "salary"/> < /td> < /tr> < /xsl:for-each> < /table> < /body> < /html> < /xsl:template> < /xsl:stylesheet>

输出