class XPath::Renderer

Public Class Methods

new(type) click to toggle source
# File lib/xpath/renderer.rb, line 9
def initialize(type)
  @type = type
end
render(node, type) click to toggle source
# File lib/xpath/renderer.rb, line 5
def self.render(node, type)
  new(type).render(node)
end

Public Instance Methods

anywhere(element_names) click to toggle source
# File lib/xpath/renderer.rb, line 55
def anywhere(element_names)
  with_element_conditions('//', element_names)
end
attribute(current, name) click to toggle source
# File lib/xpath/renderer.rb, line 63
def attribute(current, name)
  if valid_xml_name?(name)
    "#{current}/@#{name}"
  else
    "#{current}/attribute::*[local-name(.) = #{string_literal(name)}]"
  end
end
axis(current, name, element_names) click to toggle source
# File lib/xpath/renderer.rb, line 51
def axis(current, name, element_names)
  with_element_conditions("#{current}/#{name}::", element_names)
end
binary_operator(name, left, right) click to toggle source
# File lib/xpath/renderer.rb, line 71
def binary_operator(name, left, right)
  "(#{left} #{name} #{right})"
end
child(current, element_names) click to toggle source
# File lib/xpath/renderer.rb, line 47
def child(current, element_names)
  with_element_conditions("#{current}/", element_names)
end
convert_argument(argument) click to toggle source
# File lib/xpath/renderer.rb, line 18
def convert_argument(argument)
  case argument
  when Expression, Union then render(argument)
  when Array then argument.map { |element| convert_argument(element) }
  when String then string_literal(argument)
  when Literal then argument.value
  else argument.to_s
  end
end
css(current, selector) click to toggle source
# File lib/xpath/renderer.rb, line 95
def css(current, selector)
  paths = Nokogiri::CSS.xpath_for(selector).map do |xpath_selector|
    "#{current}#{xpath_selector}"
  end
  union(paths)
end
descendant(current, element_names) click to toggle source
# File lib/xpath/renderer.rb, line 43
def descendant(current, element_names)
  with_element_conditions("#{current}//", element_names)
end
function(name, *arguments) click to toggle source
# File lib/xpath/renderer.rb, line 106
def function(name, *arguments)
  "#{name}(#{arguments.join(', ')})"
end
is(one, two) click to toggle source
# File lib/xpath/renderer.rb, line 75
def is(one, two)
  if @type == :exact
    binary_operator('=', one, two)
  else
    function(:contains, one, two)
  end
end
literal(node) click to toggle source
# File lib/xpath/renderer.rb, line 91
def literal(node)
  node
end
render(node) click to toggle source
# File lib/xpath/renderer.rb, line 13
def render(node)
  arguments = node.arguments.map { |argument| convert_argument(argument) }
  send(node.expression, *arguments)
end
string_literal(string) click to toggle source
# File lib/xpath/renderer.rb, line 28
def string_literal(string)
  if string.include?("'")
    string = string.split("'", -1).map do |substr|
      "'#{substr}'"
    end.join(%q(,"'",))
    "concat(#{string})"
  else
    "'#{string}'"
  end
end
text(current) click to toggle source
# File lib/xpath/renderer.rb, line 87
def text(current)
  "#{current}/text()"
end
this_node() click to toggle source
# File lib/xpath/renderer.rb, line 39
def this_node
  '.'
end
union(*expressions) click to toggle source
# File lib/xpath/renderer.rb, line 102
def union(*expressions)
  expressions.join(' | ')
end
variable(name) click to toggle source
# File lib/xpath/renderer.rb, line 83
def variable(name)
  "%{#{name}}"
end
where(on, condition) click to toggle source
# File lib/xpath/renderer.rb, line 59
def where(on, condition)
  "#{on}[#{condition}]"
end

Private Instance Methods

valid_xml_name?(name) click to toggle source
# File lib/xpath/renderer.rb, line 122
def valid_xml_name?(name)
  name =~ /^[a-zA-Z_:][a-zA-Z0-9_:\.\-]*$/
end
with_element_conditions(expression, element_names) click to toggle source
# File lib/xpath/renderer.rb, line 112
def with_element_conditions(expression, element_names)
  if element_names.length == 1
    "#{expression}#{element_names.first}"
  elsif element_names.length > 1
    "#{expression}*[#{element_names.map { |e| "self::#{e}" }.join(' | ')}]"
  else
    "#{expression}*"
  end
end