{"id":106,"date":"2018-07-26T08:45:31","date_gmt":"2018-07-26T08:45:31","guid":{"rendered":"http:\/\/csp12.epgpbooks.inflibnet.ac.in\/?post_type=chapter&p=106"},"modified":"2018-08-02T06:13:38","modified_gmt":"2018-08-02T06:13:38","slug":"xpath","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/csp12\/chapter\/xpath\/","title":{"rendered":"XPath"},"content":{"raw":"Introduction<\/strong>\r\n\r\n \r\n

XPath (the XML Path language) is a language for finding information in an XML document. It is a major element in the XSLT standard. Without XPath knowledge you will not be able to create XSLT documents. XPath uses path expressions to navigate in XML documents and to select nodes or node-sets in an XML document. These path expressions look very much like the expressions used in JavaScript, Java, XML Schema, PHP, Python, C and C++, and lots of other languages.<\/p>\r\n \r\n

XPath is a syntax for defining parts of an XML document. It contains a library of standard functions. It is also used in XQuery, XPointer and XLink.<\/p>\r\n

Figure 14.1 shows how XPath, the path language is useful for other XML technologies like XSLT, XQuery, XPointer and XLink.<\/p>\r\n \r\n

\"\"<\/p>\r\n\r\n

\r\n\r\n \r\n\r\nXPath Nodes<\/strong>\r\n\r\n \r\n

XPath identifies seven kinds of nodes like Element node, Attribute node, Text node, Namespace node,Processing Instruction node, Comment node and Document node. XML documents are also treated as trees of nodes.<\/p>\r\n \r\n\r\nXML CODE<\/strong>\r\n\r\n<\/div>\r\n\u00a0 \u00a0<?xml version=\"1.0\" encoding=\"UTF-8\"?><\/span>\r\n\r\n<bookstore><\/span>\r\n\r\n<book><\/span>\r\n\r\n(<\/span>ROOT ELEMENT NODE<\/em>)<\/span>\r\n\r\n<title lang=\"en\">Harry Potter<\/title><\/span>\r\n\r\n<<\/span>author>J K. Rowling<\/author><\/span>\r\n\r\n<year>2005<\/year><\/span>\r\n\r\n<price>29.99<\/price><\/span>\r\n\r\n<\/book><\/span>\r\n\r\n<\/bookstore><\/span>\r\n\r\n(<\/span>ATTRIBUTE NODE<\/em>)<\/span>\r\n\r\n(<\/span>ELEMENT NODE)<\/em>\r\n\r\n \r\n\r\nRelationship of Nodes<\/strong>\r\n

\r\n\r\n\u00a0 \u00a0 PARENT NODE<\/strong>\r\n\r\n \r\n

Each element and attribute has one parent<\/em>. In the above example the <book> element is the parent of the <title>, <author>, <year>, and <price>.<\/p>\r\n \r\n\r\nCHILDREN NODE<\/strong>\r\n\r\n \r\n

Element nodes may have zero, one or more children<\/em>. The <title>, <author>, <year>, and <price> elements are all children of the <book> element.<\/p>\r\n \r\n\r\nSIBLING NODE<\/strong>\r\n\r\n<\/div>\r\n

\u00a0 Nodes that have the same parent<\/em>. The <title>, <author>, <year>, and <price> elements are all siblings ANCESTOR NODE<\/strong><\/p>\r\n \r\n

A node's parent, parent's parent, etc. The ancestors of the <title> element are the <book> element and the <bookstore> element.<\/p>\r\n \r\n\r\nDESCENDANT NODE<\/strong>\r\n\r\n \r\n

A node's children, children's children, etc. In the above example, descendants of the <bookstore> element are the <book>, <title>, <author>, <year>, and <price> elements.<\/p>\r\n \r\n\r\nXPath Syntax<\/strong>\r\n\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nXPath Syntax for Path Expression<\/strong>\r\n\r\n \r\n

XPath uses a path expression to select node or list of nodes from an XML document.<\/p>\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nXPath Syntax for Predicates<\/strong>\r\n\r\n \r\n

Predicate refers to XPath expression written in square brackets. Predicates are used to find a specific node or a node that contains a specific value. Table 14.3 shows how to give path expressions with predicates.<\/p>\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nTable 14.4 shows how to give path expressions with predicates along with attributes.\r\n\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nWildcard in XPath<\/strong>\r\n\r\n \r\n\r\nSelecting Unknown Nodes<\/strong>\r\n\r\n \r\n

XPath wildcards can be used to select unknown XML nodes. XPath defines following wildcards on nodes to be used with XPath expressions. Table 14.5 shows the different wildcards used and its description.<\/p>\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nSelecting Several Paths<\/strong>\r\n\r\n \r\n

By using the '|'<\/strong> operator in an XPath expression you can select several paths. In the Table 14.6 below we have listed some path expressions that can be given with several paths and the result of the expressions.<\/p>\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nXPath Axes<\/strong>\r\n\r\n \r\n

Axes are named so because they refers to axis on which elements are lying relative to an e lement.Following is the list of various Axes values given in Table 14.6 and Table 14.7.<\/p>\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nAn axis defines a node-set relative to the current node\r\n\r\n \r\n

\"\"<\/p>\r\n \r\n\r\nLocation Path Expression<\/strong>\r\n\r\n \r\n

A location path can be absolute or relative. An absolute location path starts with a slash ( \/ ) and a relative location path does not. In both cases the location path consists of one or more steps, each separated by a slash:<\/p>\r\n \r\n\r\nAn absolute location path will be given as: \/step\/step\/...\r\n\r\nA relative location path will be given as:\u00a0\u00a0\u00a0\u00a0\u00a0 step\/step\/...\r\n\r\nEach step is evaluated against the nodes in the current node-set.\r\n\r\n \r\n\r\nLocation Path Expression Steps & Syntax<\/strong>\r\n\r\n \r\n\r\nLocation path expression consists of following steps:\r\n

    \r\n \t
  1. An axis that defines the tree-relationship between the selected nodes and the current node.<\/li>\r\n \t
  2. A node-test that identifies a node within an axis or specifies the name of the node to be selected.<\/li>\r\n \t
  3. Zero or more predicates to further refine the selected node-set.<\/li>\r\n<\/ol>\r\nThe syntax for a location step is:\r\n\r\naxisname::nodetest[predicate]\r\n\r\n \r\n\r\nLocation Path Expression Examples<\/strong>\r\n\r\n \r\n\r\nAn XPath expression returns either a node-set, a string, a Boolean, or a number.\r\n\r\n \r\n

    \"\"<\/p>\r\n \r\n\r\nXPath Operators<\/strong>\r\n\r\n \r\n\r\nTable 14.8 shows a list of the operators that can be used in XPath expressions.\r\n\r\n \r\n

    \"\"<\/p>\r\n \r\n

    \r\n\r\n\u00a0 \u00a0 \u00a0XPath Expressions<\/strong>\r\n\r\n \r\n

    XPath query string to retrieve information from XML documents is called expression. XPath expressions are classified as,<\/p>\r\n\r\n

      \r\n \t
    • Sequence Expressions<\/li>\r\n \t
    • Range Expressions<\/li>\r\n \t
    • Filter Expressions<\/li>\r\n \t
    • Arithmetic Expression<\/li>\r\n \t
    • Comparison Expression<\/li>\r\n \t
    • Logical Expression<\/li>\r\n \t
    • For Expression<\/li>\r\n \t
    • Conditional Expression<\/li>\r\n \t
    • Quantified Expression<\/li>\r\n<\/ul>\r\n\u00a0 \u00a0 XPath Functions<\/strong>\r\n\r\n \r\n

      The XPath language provides a core library of functions that deal with Node set functions for working with node-sets, either the implicit current node set or one passed as a parameter.String functions are provided for working with strings and include type coercions.Boolean functions are provided for working with Booleans, including type coercions.Number functions are provided for working with numbers, including type coercions.<\/p>\r\n\r\n<\/div>\r\n

      \u00a0 \u00a0 XPath Function Example<\/strong><\/p>\r\n\r\n

      \r\n\r\n \r\n\r\nSome examples using XPath functions are:\r\n\r\nTo determine the number of articles written by Mr. Jones:\r\n\r\ncount(\/journal\/article[author\/last=\"Jones\"])\r\n\r\nTo find all authors whose last name begins with Mc:\r\n\r\n\/journal\/article[starts-with(author\/last,\"Mc\")]\r\n\r\n \r\n\r\n\u00a0XPath Node Set Function<\/strong>\r\n\r\n \r\n\r\nBelow is the list of some of the XPath Node set functions.\r\n\r\n \r\n\r\nnumber last() <\/strong>- Returns the index of the last item of the current node set.\r\n\r\nExample - \/journal\/article[last()]\r\n\r\nnumber position() - <\/strong>Returns the index of the current item in the current node set.\r\n\r\nExample - \/journal\/article[position()<3]\r\n\r\nnumber count(node-set) - <\/strong>Returns the number of items in the argument node set.\r\n\r\nExample - count(\/journal\/article)\r\n\r\nnode-set id(object) - <\/strong>Returns the elements with the ID specified.\r\n\r\nExample - id(\"article.1\")\/author\/last\r\n\r\n \r\n\r\nXPath String Function<\/strong>\r\n\r\n \r\n\r\nBelow is the list of some of the XPath string functions.\r\n\r\nstring string(object?) <\/strong>- Converts an object (possibly the current context node) to its string value. Example - \/journal\/article\/author[string()='Jones']\r\n\r\nstring concat(string, string, string*) <\/strong>- Concatenates two or more strings together.\r\n\r\nExample - concat(author\/salutation, ' ', author\/last)\r\n\r\nstring starts-with(string, string) <\/strong>- Determines if the first argument starts with the second\u00a0argument string.\r\n\r\nExample - \/journal\/article[starts-with(title, 'Advanced')]\r\n\r\nstring ends-with(string, string) <\/strong>- Determines if the first argument ends with the second argument string.\r\n\r\nExample - \/journal\/article[ends-with(title, 'Advanced')]\r\n\r\nstring contains(string, string) - <\/strong>Determines if the first argument contains the second argument string.<\/span>\r\n\r\nExample - \/journal\/article[contains(title, 'XPath')]<\/span>\r\n\r\nstring substring-before(string, string) - <\/strong>Retrieves the substring of the first argument that occurs before the first occurrence of the second argument string.<\/span>\r\n\r\nExample - substring-before(\/journal\/article[1]\/date, '\/')<\/span>\r\n\r\nstring substring-after(string, string) - <\/strong>Retrieves the substring of the first argument that occurs after the first occurrence of the second argument string.<\/span>\r\n\r\nExample - substring-after(\/journal\/article[1]\/date, '\/')<\/span>\r\n\r\nstring substring(string, number, number?) - <\/strong>Retrieves the substring of the first argument starting at the index of the second number argument, for the length of the optional third argument.<\/span>\r\n\r\nExample - substring('Jones', 3)<\/span>\r\n\r\nnumber string-length(string?) - <\/strong>Determines the length of a string, or the current context node\u00a0<\/span>coerced to a string.<\/span>\r\n\r\nExample - \/journal\/article[string-length(author\/last) > 9]<\/span>\r\n\r\nstring normalize-space(string?) - <\/strong>Retrieves the string argument or context node with all space normalized, trimming white space from the ends and compressing consecutive white space elements to a single space.<\/span>\r\n\r\nExample - normalize-space(\/journal\/article[1]\/content)<\/span>\r\n\r\n \r\n\r\nXPath Boolean Function<\/strong>\r\n\r\n<\/div>\r\n
      \r\n

      \u00a0 \u00a0Below is the list of some of the XPath Boolean functions.<\/p>\r\n

      Boolean boolean(object) - <\/strong>Converts the argument to a Boolean value.<\/p>\r\n

      Example - boolean(\/journal\/article\/author\/last[.='Jones'])<\/p>\r\n

      Boolean not(boolean) - <\/strong>Negates the boolean value.<\/p>\r\n

      Example - not(\/journal\/article\/author\/last[.='Jones'])<\/p>\r\n

      Boolean boolean-from-string(string) - <\/strong>Returns true if the required parameter string is true, 1, or<\/p>\r\n

      Yes. In all other conditions, false is returned.<\/p>\r\n

      Example - boolean-from-string(..\/pay_entire_amount)<\/p>\r\n

      Boolean true() - <\/strong>The Boolean value is true.<\/p>\r\n

      Boolean false() - <\/strong>The Boolean value is false.<\/span><\/p>\r\n

      object if(boolean,object,object) - <\/strong>Evaluates the first parameter as a Boolean, returning the second parameter when true, otherwise the third parameter.<\/span><\/p>\r\n

      Example \u2013 if(\/journal\/article\/author\/last[.='Jones'],'Match found','No match')<\/span><\/p>\r\n \r\n

      XPath Number Function<\/strong><\/p>\r\n

      Below is the list of some of the XPath Number functions.<\/span><\/p>\r\n

      number number(object?) - <\/strong>Converts the argument or context node to a number value.<\/span><\/p>\r\n

      Example - \/journal[number(year)=2003]<\/span><\/p>\r\n

      number sum(node-set) - <\/strong>Sums the node set value.<\/span><\/p>\r\n

      Example - sum(\/journal\/article\/author\/age)<\/span><\/p>\r\n

      number floor(number) - <\/strong>Returns the largest integer that is not greater than the number\u00a0<\/span>argument.<\/span><\/p>\r\n

      Example - floor(100.5)=100<\/span><\/p>\r\n

      number round(number) - <\/strong>Rounds the number argument.<\/span><\/p>\r\n

      Example - ceiling(100.3)=100<\/span><\/p>\r\n \r\n

      Summary<\/strong><\/p>\r\n\r\n<\/div>\r\n

      \r\n\r\n \r\n

      This module explains about XPath and how to define XPath expressions to navigate in XML documents. It also explores about XPath syntax, Location path expression ,Absolute\/Relative path, Predicate, Wildcard, Axes and XPath operators and functions.<\/p>\r\n\r\n<\/div>\r\n ","rendered":"

      Introduction<\/strong><\/p>\n

       <\/p>\n

      XPath (the XML Path language) is a language for finding information in an XML document. It is a major element in the XSLT standard. Without XPath knowledge you will not be able to create XSLT documents. XPath uses path expressions to navigate in XML documents and to select nodes or node-sets in an XML document. These path expressions look very much like the expressions used in JavaScript, Java, XML Schema, PHP, Python, C and C++, and lots of other languages.<\/p>\n

       <\/p>\n

      XPath is a syntax for defining parts of an XML document. It contains a library of standard functions. It is also used in XQuery, XPointer and XLink.<\/p>\n

      Figure 14.1 shows how XPath, the path language is useful for other XML technologies like XSLT, XQuery, XPointer and XLink.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

      \n

       <\/p>\n

      XPath Nodes<\/strong><\/p>\n

       <\/p>\n

      XPath identifies seven kinds of nodes like Element node, Attribute node, Text node, Namespace node,Processing Instruction node, Comment node and Document node. XML documents are also treated as trees of nodes.<\/p>\n

       <\/p>\n

      XML CODE<\/strong><\/p>\n<\/div>\n

      \u00a0 \u00a0<?xml version=”1.0″ encoding=”UTF-8″?><\/span><\/p>\n

      <bookstore><\/span><\/p>\n

      <book><\/span><\/p>\n

      (<\/span>ROOT ELEMENT NODE<\/em>)<\/span><\/p>\n

      <title lang=”en”>Harry Potter<\/title><\/span><\/p>\n

      <<\/span>author>J K. Rowling<\/author><\/span><\/p>\n

      <year>2005<\/year><\/span><\/p>\n

      <price>29.99<\/price><\/span><\/p>\n

      <\/book><\/span><\/p>\n

      <\/bookstore><\/span><\/p>\n

      (<\/span>ATTRIBUTE NODE<\/em>)<\/span><\/p>\n

      (<\/span>ELEMENT NODE)<\/em><\/p>\n

       <\/p>\n

      Relationship of Nodes<\/strong><\/p>\n

      \n

      \u00a0 \u00a0 PARENT NODE<\/strong><\/p>\n

       <\/p>\n

      Each element and attribute has one parent<\/em>. In the above example the <book> element is the parent of the <title>, <author>, <year>, and <price>.<\/p>\n

       <\/p>\n

      CHILDREN NODE<\/strong><\/p>\n

       <\/p>\n

      Element nodes may have zero, one or more children<\/em>. The <title>, <author>, <year>, and <price> elements are all children of the <book> element.<\/p>\n

       <\/p>\n

      SIBLING NODE<\/strong><\/p>\n<\/div>\n

      \u00a0 Nodes that have the same parent<\/em>. The <title>, <author>, <year>, and <price> elements are all siblings ANCESTOR NODE<\/strong><\/p>\n

       <\/p>\n

      A node’s parent, parent’s parent, etc. The ancestors of the <title> element are the <book> element and the <bookstore> element.<\/p>\n

       <\/p>\n

      DESCENDANT NODE<\/strong><\/p>\n

       <\/p>\n

      A node’s children, children’s children, etc. In the above example, descendants of the <bookstore> element are the <book>, <title>, <author>, <year>, and <price> elements.<\/p>\n

       <\/p>\n

      XPath Syntax<\/strong><\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      XPath Syntax for Path Expression<\/strong><\/p>\n

       <\/p>\n

      XPath uses a path expression to select node or list of nodes from an XML document.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      XPath Syntax for Predicates<\/strong><\/p>\n

       <\/p>\n

      Predicate refers to XPath expression written in square brackets. Predicates are used to find a specific node or a node that contains a specific value. Table 14.3 shows how to give path expressions with predicates.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      Table 14.4 shows how to give path expressions with predicates along with attributes.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      Wildcard in XPath<\/strong><\/p>\n

       <\/p>\n

      Selecting Unknown Nodes<\/strong><\/p>\n

       <\/p>\n

      XPath wildcards can be used to select unknown XML nodes. XPath defines following wildcards on nodes to be used with XPath expressions. Table 14.5 shows the different wildcards used and its description.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      Selecting Several Paths<\/strong><\/p>\n

       <\/p>\n

      By using the ‘|’<\/strong> operator in an XPath expression you can select several paths. In the Table 14.6 below we have listed some path expressions that can be given with several paths and the result of the expressions.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      XPath Axes<\/strong><\/p>\n

       <\/p>\n

      Axes are named so because they refers to axis on which elements are lying relative to an e lement.Following is the list of various Axes values given in Table 14.6 and Table 14.7.<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      An axis defines a node-set relative to the current node<\/p>\n

       <\/p>\n

      \"\"<\/p>\n

       <\/p>\n

      Location Path Expression<\/strong><\/p>\n

       <\/p>\n

      A location path can be absolute or relative. An absolute location path starts with a slash ( \/ ) and a relative location path does not. In both cases the location path consists of one or more steps, each separated by a slash:<\/p>\n

       <\/p>\n

      An absolute location path will be given as: \/step\/step\/…<\/p>\n

      A relative location path will be given as:\u00a0\u00a0\u00a0\u00a0\u00a0 step\/step\/…<\/p>\n

      Each step is evaluated against the nodes in the current node-set.<\/p>\n

       <\/p>\n

      Location Path Expression Steps & Syntax<\/strong><\/p>\n

       <\/p>\n

      Location path expression consists of following steps:<\/p>\n

        \n
      1. An axis that defines the tree-relationship between the selected nodes and the current node.<\/li>\n
      2. A node-test that identifies a node within an axis or specifies the name of the node to be selected.<\/li>\n
      3. Zero or more predicates to further refine the selected node-set.<\/li>\n<\/ol>\n

        The syntax for a location step is:<\/p>\n

        axisname::nodetest[predicate]<\/p>\n

         <\/p>\n

        Location Path Expression Examples<\/strong><\/p>\n

         <\/p>\n

        An XPath expression returns either a node-set, a string, a Boolean, or a number.<\/p>\n

         <\/p>\n

        \"\"<\/p>\n

         <\/p>\n

        XPath Operators<\/strong><\/p>\n

         <\/p>\n

        Table 14.8 shows a list of the operators that can be used in XPath expressions.<\/p>\n

         <\/p>\n

        \"\"<\/p>\n

         <\/p>\n

        \n

        \u00a0 \u00a0 \u00a0XPath Expressions<\/strong><\/p>\n

         <\/p>\n

        XPath query string to retrieve information from XML documents is called expression. XPath expressions are classified as,<\/p>\n

          \n
        • Sequence Expressions<\/li>\n
        • Range Expressions<\/li>\n
        • Filter Expressions<\/li>\n
        • Arithmetic Expression<\/li>\n
        • Comparison Expression<\/li>\n
        • Logical Expression<\/li>\n
        • For Expression<\/li>\n
        • Conditional Expression<\/li>\n
        • Quantified Expression<\/li>\n<\/ul>\n

          \u00a0 \u00a0 XPath Functions<\/strong><\/p>\n

           <\/p>\n

          The XPath language provides a core library of functions that deal with Node set functions for working with node-sets, either the implicit current node set or one passed as a parameter.String functions are provided for working with strings and include type coercions.Boolean functions are provided for working with Booleans, including type coercions.Number functions are provided for working with numbers, including type coercions.<\/p>\n<\/div>\n

          \u00a0 \u00a0 XPath Function Example<\/strong><\/p>\n

          \n

           <\/p>\n

          Some examples using XPath functions are:<\/p>\n

          To determine the number of articles written by Mr. Jones:<\/p>\n

          count(\/journal\/article[author\/last=”Jones”])<\/p>\n

          To find all authors whose last name begins with Mc:<\/p>\n

          \/journal\/article[starts-with(author\/last,”Mc”)]<\/p>\n

           <\/p>\n

          \u00a0XPath Node Set Function<\/strong><\/p>\n

           <\/p>\n

          Below is the list of some of the XPath Node set functions.<\/p>\n

           <\/p>\n

          number last() <\/strong>– Returns the index of the last item of the current node set.<\/p>\n

          Example – \/journal\/article[last()]<\/p>\n

          number position() – <\/strong>Returns the index of the current item in the current node set.<\/p>\n

          Example – \/journal\/article[position()<3]<\/p>\n

          number count(node-set) – <\/strong>Returns the number of items in the argument node set.<\/p>\n

          Example – count(\/journal\/article)<\/p>\n

          node-set id(object) – <\/strong>Returns the elements with the ID specified.<\/p>\n

          Example – id(“article.1”)\/author\/last<\/p>\n

           <\/p>\n

          XPath String Function<\/strong><\/p>\n

           <\/p>\n

          Below is the list of some of the XPath string functions.<\/p>\n

          string string(object?) <\/strong>– Converts an object (possibly the current context node) to its string value. Example – \/journal\/article\/author[string()=’Jones’]<\/p>\n

          string concat(string, string, string*) <\/strong>– Concatenates two or more strings together.<\/p>\n

          Example – concat(author\/salutation, ‘ ‘, author\/last)<\/p>\n

          string starts-with(string, string) <\/strong>– Determines if the first argument starts with the second\u00a0argument string.<\/p>\n

          Example – \/journal\/article[starts-with(title, ‘Advanced’)]<\/p>\n

          string ends-with(string, string) <\/strong>– Determines if the first argument ends with the second argument string.<\/p>\n

          Example – \/journal\/article[ends-with(title, ‘Advanced’)]<\/p>\n

          string contains(string, string) – <\/strong>Determines if the first argument contains the second argument string.<\/span><\/p>\n

          Example – \/journal\/article[contains(title, ‘XPath’)]<\/span><\/p>\n

          string substring-before(string, string) – <\/strong>Retrieves the substring of the first argument that occurs before the first occurrence of the second argument string.<\/span><\/p>\n

          Example – substring-before(\/journal\/article[1]\/date, ‘\/’)<\/span><\/p>\n

          string substring-after(string, string) – <\/strong>Retrieves the substring of the first argument that occurs after the first occurrence of the second argument string.<\/span><\/p>\n

          Example – substring-after(\/journal\/article[1]\/date, ‘\/’)<\/span><\/p>\n

          string substring(string, number, number?) – <\/strong>Retrieves the substring of the first argument starting at the index of the second number argument, for the length of the optional third argument.<\/span><\/p>\n

          Example – substring(‘Jones’, 3)<\/span><\/p>\n

          number string-length(string?) – <\/strong>Determines the length of a string, or the current context node\u00a0<\/span>coerced to a string.<\/span><\/p>\n

          Example – \/journal\/article[string-length(author\/last) > 9]<\/span><\/p>\n

          string normalize-space(string?) – <\/strong>Retrieves the string argument or context node with all space normalized, trimming white space from the ends and compressing consecutive white space elements to a single space.<\/span><\/p>\n

          Example – normalize-space(\/journal\/article[1]\/content)<\/span><\/p>\n

           <\/p>\n

          XPath Boolean Function<\/strong><\/p>\n<\/div>\n

          \n

          \u00a0 \u00a0Below is the list of some of the XPath Boolean functions.<\/p>\n

          Boolean boolean(object) – <\/strong>Converts the argument to a Boolean value.<\/p>\n

          Example – boolean(\/journal\/article\/author\/last[.=’Jones’])<\/p>\n

          Boolean not(boolean) – <\/strong>Negates the boolean value.<\/p>\n

          Example – not(\/journal\/article\/author\/last[.=’Jones’])<\/p>\n

          Boolean boolean-from-string(string) – <\/strong>Returns true if the required parameter string is true, 1, or<\/p>\n

          Yes. In all other conditions, false is returned.<\/p>\n

          Example – boolean-from-string(..\/pay_entire_amount)<\/p>\n

          Boolean true() – <\/strong>The Boolean value is true.<\/p>\n

          Boolean false() – <\/strong>The Boolean value is false.<\/span><\/p>\n

          object if(boolean,object,object) – <\/strong>Evaluates the first parameter as a Boolean, returning the second parameter when true, otherwise the third parameter.<\/span><\/p>\n

          Example \u2013 if(\/journal\/article\/author\/last[.=’Jones’],’Match found’,’No match’)<\/span><\/p>\n

           <\/p>\n

          XPath Number Function<\/strong><\/p>\n

          Below is the list of some of the XPath Number functions.<\/span><\/p>\n

          number number(object?) – <\/strong>Converts the argument or context node to a number value.<\/span><\/p>\n

          Example – \/journal[number(year)=2003]<\/span><\/p>\n

          number sum(node-set) – <\/strong>Sums the node set value.<\/span><\/p>\n

          Example – sum(\/journal\/article\/author\/age)<\/span><\/p>\n

          number floor(number) – <\/strong>Returns the largest integer that is not greater than the number\u00a0<\/span>argument.<\/span><\/p>\n

          Example – floor(100.5)=100<\/span><\/p>\n

          number round(number) – <\/strong>Rounds the number argument.<\/span><\/p>\n

          Example – ceiling(100.3)=100<\/span><\/p>\n

           <\/p>\n

          Summary<\/strong><\/p>\n<\/div>\n

          \n

           <\/p>\n

          This module explains about XPath and how to define XPath expressions to navigate in XML documents. It also explores about XPath syntax, Location path expression ,Absolute\/Relative path, Predicate, Wildcard, Axes and XPath operators and functions.<\/p>\n<\/div>\n

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