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  • rexml/xpath_parser.rb

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REXML::XPathParser

You don't want to use this class. Really. Use XPath, which is a wrapper for this class. Believe me. You don't want to poke around in here. There is strange, dark magic at work in this code. Beware. Go back! Go back while you still can!

Constants

ALL

Expr takes a stack of path elements and a set of nodes (either a Parent or an Array and returns an Array of matching nodes

ELEMENTS
LITERAL

Public Class Methods

new( ) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 39
def initialize( )
  @parser = REXML::Parsers::XPathParser.new
  @namespaces = nil
  @variables = {}
end

Public Instance Methods

[]=( variable_name, value ) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 76
def []=( variable_name, value )
  @variables[ variable_name ] = value
end
first( path_stack, node ) click to toggle source

Performs a depth-first (document order) XPath search, and returns the first match. This is the fastest, lightest way to return a single result.

FIXME: This method is incomplete!

 
               # File rexml/xpath_parser.rb, line 85
def first( path_stack, node )
  #puts "#{depth}) Entering match( #{path.inspect}, #{tree.inspect} )"
  return nil if path.size == 0

  case path[0]
  when :document
    # do nothing
    return first( path[1..-1], node )
  when :child
    for c in node.children
      #puts "#{depth}) CHILD checking #{name(c)}"
      r = first( path[1..-1], c )
      #puts "#{depth}) RETURNING #{r.inspect}" if r
      return r if r
    end
  when :qname
    name = path[2]
    #puts "#{depth}) QNAME #{name(tree)} == #{name} (path => #{path.size})"
    if node.name == name
      #puts "#{depth}) RETURNING #{tree.inspect}" if path.size == 3
      return node if path.size == 3
      return first( path[3..-1], node )
    else
      return nil
    end
  when :descendant_or_self
    r = first( path[1..-1], node )
    return r if r
    for c in node.children
      r = first( path, c )
      return r if r
    end
  when :node
    return first( path[1..-1], node )
  when :any
    return first( path[1..-1], node )
  end
  return nil
end
get_first(path, nodeset) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 63
def get_first path, nodeset
 #puts "#"*40
 path_stack = @parser.parse( path )
 #puts "PARSE: #{path} => #{path_stack.inspect}"
 #puts "PARSE: nodeset = #{nodeset.inspect}"
 first( path_stack, nodeset )
end
match( path_stack, nodeset ) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 126
def match( path_stack, nodeset ) 
  #puts "MATCH: path_stack = #{path_stack.inspect}"
  #puts "MATCH: nodeset = #{nodeset.inspect}"
  r = expr( path_stack, nodeset )
  #puts "MAIN EXPR => #{r.inspect}"
  r
end
namespaces=( namespaces={} ) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 45
def namespaces=( namespaces={} )
  Functions::namespace_context = namespaces
  @namespaces = namespaces
end
parse(path, nodeset) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 55
def parse path, nodeset
 #puts "#"*40
 path_stack = @parser.parse( path )
 #puts "PARSE: #{path} => #{path_stack.inspect}"
 #puts "PARSE: nodeset = #{nodeset.inspect}"
 match( path_stack, nodeset )
end
predicate(path, nodeset) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 71
def predicate path, nodeset
  path_stack = @parser.parse( path )
  expr( path_stack, nodeset )
end
variables=( vars={} ) click to toggle source 
 
               # File rexml/xpath_parser.rb, line 50
def variables=( vars={} )
  Functions::variables = vars
  @variables = vars
end