class 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

DEBUG
LITERAL

Public Class Methods

new (strict: false)

Source

# File lib/rexml/xpath_parser.rb, line 60
def initialize(strict: false)
  @debug = DEBUG
  @parser = REXML::Parsers::XPathParser.new
  @namespaces = nil
  @variables = {}
  @functions = FunctionsClass.new
  @nest = 0
  @strict = strict
end

Public Instance Methods

[]= ( variable_name, value )

Source

# File lib/rexml/xpath_parser.rb, line 108
def []=( variable_name, value )
  @variables[ variable_name ] = value
end

first ( path_stack, node )

Source

# File lib/rexml/xpath_parser.rb, line 117
def first( path_stack, node )
  return nil if path.size == 0

  case path[0]
  when :document
    # do nothing
    first( path[1..-1], node )
  when :child
    for c in node.children
      r = first( path[1..-1], c )
      return r if r
    end
  when :qname
    name = path[2]
    if node.name == name
      return node if path.size == 3
      first( path[3..-1], node )
    else
      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
    first( path[1..-1], node )
  when :any
    first( path[1..-1], node )
  else
    nil
  end
end

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!

get_first (path, node)

Source

# File lib/rexml/xpath_parser.rb, line 98
def get_first path, node
  path_stack = @parser.parse( path )
  first( path_stack, node )
end

match (path_stack, node)

Source

# File lib/rexml/xpath_parser.rb, line 154
def match(path_stack, node)
  nodeset = [node]
  result = expr(path_stack, nodeset)
  case result
  when Array # nodeset
    result.uniq
  else
    [result]
  end
end

namespaces= ( namespaces={} )

Source

# File lib/rexml/xpath_parser.rb, line 70
def namespaces=( namespaces={} )
  @functions.namespace_context = namespaces
  @namespaces = namespaces
end

parse (path, node)

Source

# File lib/rexml/xpath_parser.rb, line 80
def parse path, node
  path_stack = @parser.parse( path )
  if node.is_a?(Array)
    Kernel.warn("REXML::XPath.each, REXML::XPath.first, REXML::XPath.match dropped support for nodeset...", uplevel: 1)
    return [] if node.empty?
    node = node.first
  end

  document = node.document
  if document
    document.__send__(:enable_cache) do
      match( path_stack, node )
    end
  else
    match( path_stack, node )
  end
end

predicate (path, node)

Source

# File lib/rexml/xpath_parser.rb, line 103
def predicate path, node
  path_stack = @parser.parse( path )
  match( path_stack, node )
end

variables= ( vars={} )

Source

# File lib/rexml/xpath_parser.rb, line 75
def variables=( vars={} )
  @functions.variables = vars
  @variables = vars
end