81 lines
3.3 KiB
Ruby
81 lines
3.3 KiB
Ruby
require 'rexml/functions'
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require 'rexml/xpath_parser'
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module REXML
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# Wrapper class. Use this class to access the XPath functions.
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class XPath
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include Functions
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# A base Hash object, supposing to be used when initializing a
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# default empty namespaces set, but is currently unused.
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# TODO: either set the namespaces=EMPTY_HASH, or deprecate this.
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EMPTY_HASH = {}
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# Finds and returns the first node that matches the supplied xpath.
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# element::
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# The context element
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# path::
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# The xpath to search for. If not supplied or nil, returns the first
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# node matching '*'.
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# namespaces::
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# If supplied, a Hash which defines a namespace mapping.
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# variables::
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# If supplied, a Hash which maps $variables in the query
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# to values. This can be used to avoid XPath injection attacks
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# or to automatically handle escaping string values.
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#
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# XPath.first( node )
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# XPath.first( doc, "//b"} )
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# XPath.first( node, "a/x:b", { "x"=>"http://doofus" } )
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# XPath.first( node, '/book/publisher/text()=$publisher', {}, {"publisher"=>"O'Reilly"})
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def XPath::first element, path=nil, namespaces=nil, variables={}
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raise "The namespaces argument, if supplied, must be a hash object." unless namespaces.nil? or namespaces.kind_of?(Hash)
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raise "The variables argument, if supplied, must be a hash object." unless variables.kind_of?(Hash)
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parser = XPathParser.new
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parser.namespaces = namespaces
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parser.variables = variables
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path = "*" unless path
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element = [element] unless element.kind_of? Array
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parser.parse(path, element).flatten[0]
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end
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# Iterates over nodes that match the given path, calling the supplied
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# block with the match.
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# element::
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# The context element
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# path::
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# The xpath to search for. If not supplied or nil, defaults to '*'
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# namespaces::
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# If supplied, a Hash which defines a namespace mapping
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# variables::
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# If supplied, a Hash which maps $variables in the query
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# to values. This can be used to avoid XPath injection attacks
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# or to automatically handle escaping string values.
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#
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# XPath.each( node ) { |el| ... }
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# XPath.each( node, '/*[@attr='v']' ) { |el| ... }
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# XPath.each( node, 'ancestor::x' ) { |el| ... }
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# XPath.each( node, '/book/publisher/text()=$publisher', {}, {"publisher"=>"O'Reilly"}) \
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# {|el| ... }
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def XPath::each element, path=nil, namespaces=nil, variables={}, &block
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raise "The namespaces argument, if supplied, must be a hash object." unless namespaces.nil? or namespaces.kind_of?(Hash)
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raise "The variables argument, if supplied, must be a hash object." unless variables.kind_of?(Hash)
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parser = XPathParser.new
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parser.namespaces = namespaces
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parser.variables = variables
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path = "*" unless path
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element = [element] unless element.kind_of? Array
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parser.parse(path, element).each( &block )
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end
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# Returns an array of nodes matching a given XPath.
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def XPath::match element, path=nil, namespaces=nil, variables={}
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parser = XPathParser.new
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parser.namespaces = namespaces
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parser.variables = variables
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path = "*" unless path
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element = [element] unless element.kind_of? Array
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parser.parse(path,element)
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end
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end
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end
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