Class: Nokogiri::CSS::XPathVisitor

Inherits:
Object
  • Object
show all
Defined in:
lib/nokogiri/css/xpath_visitor.rb

Overview

:nodoc:

Instance Method Summary collapse

Instance Method Details

#accept(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 178

def accept node
  node.accept(self)
end

#visit_attribute_condition(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 75

def visit_attribute_condition node
   attribute = if (node.value.first.type == :FUNCTION) or (node.value.first.value.first =~ /::/)
                 ''
               else
                 '@'
               end
  attribute += node.value.first.accept(self)

  # Support non-standard css
  attribute.gsub!(/^@@/, '@')

  return attribute unless node.value.length == 3

  value = node.value.last
  value = "'#{value}'" if value !~ /^['"]/

  if (value[0]==value[-1]) && %q{"'}.include?(value[0])
    str_value = value[1..-2]
    if str_value.include?(value[0])
      value = 'concat("' + str_value.split('"', -1).join(%q{", '"', "}) + '", "")'
    end
  end

  case node.value[1]
  when :equal
    attribute + " = " + "#{value}"
  when :not_equal
    attribute + " != " + "#{value}"
  when :substring_match
    "contains(#{attribute}, #{value})"
  when :prefix_match
    "starts-with(#{attribute}, #{value})"
  when :dash_match
    "#{attribute} = #{value} or starts-with(#{attribute}, concat(#{value}, '-'))"
  when :includes
    "contains(concat(\" \", #{attribute}, \" \"),concat(\" \", #{value}, \" \"))"
  when :suffix_match
    "substring(#{attribute}, string-length(#{attribute}) - " +
      "string-length(#{value}) + 1, string-length(#{value})) = #{value}"
  else
    attribute + " #{node.value[1]} " + "#{value}"
  end
end

#visit_class_condition(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 144

def visit_class_condition node
  "contains(concat(' ', normalize-space(@class), ' '), ' #{node.value.first} ')"
end

#visit_combinator(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 148

def visit_combinator node
  if is_of_type_pseudo_class?(node.value.last)
    "#{node.value.first.accept(self) if node.value.first}][#{node.value.last.accept(self)}"
  else
    "#{node.value.first.accept(self) if node.value.first} and #{node.value.last.accept(self)}"
  end
end

#visit_conditional_selector(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 169

def visit_conditional_selector node
  node.value.first.accept(self) + '[' +
  node.value.last.accept(self) + ']'
end

#visit_element_name(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 174

def visit_element_name node
  node.value.first
end

#visit_function(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 4

def visit_function node

  msg = :"visit_function_#{node.value.first.gsub(/[(]/, '')}"
  return self.send(msg, node) if self.respond_to?(msg)

  case node.value.first
  when /^text\(/
    'child::text()'
  when /^self\(/
    "self::#{node.value[1]}"
  when /^eq\(/
    "position() = #{node.value[1]}"
  when /^(nth|nth-of-type)\(/
    if node.value[1].is_a?(Nokogiri::CSS::Node) and node.value[1].type == :NTH
      nth(node.value[1])
    else
      "position() = #{node.value[1]}"
    end
  when /^nth-child\(/
    if node.value[1].is_a?(Nokogiri::CSS::Node) and node.value[1].type == :NTH
      nth(node.value[1], :child => true)
    else
      "count(preceding-sibling::*) = #{node.value[1].to_i-1}"
    end
  when /^nth-last-of-type\(/
    if node.value[1].is_a?(Nokogiri::CSS::Node) and node.value[1].type == :NTH
      nth(node.value[1], :last => true)
    else
      index = node.value[1].to_i - 1
      index == 0 ? "position() = last()" : "position() = last() - #{index}"
    end
  when /^nth-last-child\(/
    if node.value[1].is_a?(Nokogiri::CSS::Node) and node.value[1].type == :NTH
      nth(node.value[1], :last => true, :child => true)
    else
      "count(following-sibling::*) = #{node.value[1].to_i-1}"
    end
  when /^(first|first-of-type)\(/
    "position() = 1"
  when /^(last|last-of-type)\(/
    "position() = last()"
  when /^contains\(/
    "contains(., #{node.value[1]})"
  when /^gt\(/
    "position() > #{node.value[1]}"
  when /^only-child\(/
    "last() = 1"
  when /^comment\(/
    "comment()"
  when /^has\(/
    node.value[1].accept(self)
  else
    args = ['.'] + node.value[1..-1]
    "#{node.value.first}#{args.join(', ')})"
  end
end

#visit_id(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 70

def visit_id node
  node.value.first =~ /^#(.*)$/
  "@id = '#{$1}'"
end

#visit_not(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 61

def visit_not node
  child = node.value.first
  if :ELEMENT_NAME == child.type
    "not(self::#{child.accept(self)})"
  else
    "not(#{child.accept(self)})"
  end
end

#visit_pseudo_class(node) ⇒ Object


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# File 'lib/nokogiri/css/xpath_visitor.rb', line 119

def visit_pseudo_class node
  if node.value.first.is_a?(Nokogiri::CSS::Node) and node.value.first.type == :FUNCTION
    node.value.first.accept(self)
  else
    msg = :"visit_pseudo_class_#{node.value.first.gsub(/[(]/, '')}"
    return self.send(msg, node) if self.respond_to?(msg)

    case node.value.first
    when "first" then "position() = 1"
    when "first-child" then "count(preceding-sibling::*) = 0"
    when "last" then "position() = last()"
    when "last-child" then "count(following-sibling::*) = 0"
    when "first-of-type" then "position() = 1"
    when "last-of-type" then "position() = last()"
    when "only-child" then "count(preceding-sibling::*) = 0 and count(following-sibling::*) = 0"
    when "only-of-type" then "last() = 1"
    when "empty" then "not(node())"
    when "parent" then "node()"
    when "root" then "not(parent::*)"
    else
      node.value.first + "(.)"
    end
  end
end