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



179
180
181
# File 'lib/nokogiri/css/xpath_visitor.rb', line 179

def accept node
  node.accept(self)
end

#visit_attribute_condition(node) ⇒ Object



76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
# File 'lib/nokogiri/css/xpath_visitor.rb', line 76

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



145
146
147
# File 'lib/nokogiri/css/xpath_visitor.rb', line 145

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

#visit_combinator(node) ⇒ Object



149
150
151
152
153
154
155
# File 'lib/nokogiri/css/xpath_visitor.rb', line 149

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



170
171
172
173
# File 'lib/nokogiri/css/xpath_visitor.rb', line 170

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

#visit_element_name(node) ⇒ Object



175
176
177
# File 'lib/nokogiri/css/xpath_visitor.rb', line 175

def visit_element_name node
  node.value.first
end

#visit_function(node) ⇒ Object



4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
# 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\(/
    is_direct = node.value[1].value[0].nil? # e.g. "has(> a)", "has(~ a)", "has(+ a)"
    ".#{"//" if !is_direct}#{node.value[1].accept(self)}"
  else
    args = ['.'] + node.value[1..-1]
    "#{node.value.first}#{args.join(', ')})"
  end
end

#visit_id(node) ⇒ Object



71
72
73
74
# File 'lib/nokogiri/css/xpath_visitor.rb', line 71

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

#visit_not(node) ⇒ Object



62
63
64
65
66
67
68
69
# File 'lib/nokogiri/css/xpath_visitor.rb', line 62

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



120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
# File 'lib/nokogiri/css/xpath_visitor.rb', line 120

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