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author | Piotr Sarnacki <drogus@gmail.com> | 2012-06-09 14:40:50 +0200 |
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committer | Piotr Sarnacki <drogus@gmail.com> | 2012-08-28 10:51:03 +0200 |
commit | ba83aa7f03d2742dd242a45229e0f67785871515 (patch) | |
tree | ff35607be2e123302ba0db65f5c644d577c05dae /actionpack/lib/action_view/vendor/html-scanner/html/selector.rb | |
parent | 4efad291c11a7c4fcf178fbb887b4845eaf61757 (diff) | |
download | rails-ba83aa7f03d2742dd242a45229e0f67785871515.tar.gz rails-ba83aa7f03d2742dd242a45229e0f67785871515.tar.bz2 rails-ba83aa7f03d2742dd242a45229e0f67785871515.zip |
Move action_controller/vendor/html-scanner to action_view
This is another step in moving Action View's dependencies in Action Pack
to Action View itself. Also, HtmlScanner seems to be better suited for
views rather than controllers.
Diffstat (limited to 'actionpack/lib/action_view/vendor/html-scanner/html/selector.rb')
-rw-r--r-- | actionpack/lib/action_view/vendor/html-scanner/html/selector.rb | 830 |
1 files changed, 830 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/vendor/html-scanner/html/selector.rb b/actionpack/lib/action_view/vendor/html-scanner/html/selector.rb new file mode 100644 index 0000000000..1eadfc0390 --- /dev/null +++ b/actionpack/lib/action_view/vendor/html-scanner/html/selector.rb @@ -0,0 +1,830 @@ +#-- +# Copyright (c) 2006 Assaf Arkin (http://labnotes.org) +# Under MIT and/or CC By license. +#++ + +module HTML + + # Selects HTML elements using CSS 2 selectors. + # + # The +Selector+ class uses CSS selector expressions to match and select + # HTML elements. + # + # For example: + # selector = HTML::Selector.new "form.login[action=/login]" + # creates a new selector that matches any +form+ element with the class + # +login+ and an attribute +action+ with the value <tt>/login</tt>. + # + # === Matching Elements + # + # Use the #match method to determine if an element matches the selector. + # + # For simple selectors, the method returns an array with that element, + # or +nil+ if the element does not match. For complex selectors (see below) + # the method returns an array with all matched elements, of +nil+ if no + # match found. + # + # For example: + # if selector.match(element) + # puts "Element is a login form" + # end + # + # === Selecting Elements + # + # Use the #select method to select all matching elements starting with + # one element and going through all children in depth-first order. + # + # This method returns an array of all matching elements, an empty array + # if no match is found + # + # For example: + # selector = HTML::Selector.new "input[type=text]" + # matches = selector.select(element) + # matches.each do |match| + # puts "Found text field with name #{match.attributes['name']}" + # end + # + # === Expressions + # + # Selectors can match elements using any of the following criteria: + # * <tt>name</tt> -- Match an element based on its name (tag name). + # For example, <tt>p</tt> to match a paragraph. You can use <tt>*</tt> + # to match any element. + # * <tt>#</tt><tt>id</tt> -- Match an element based on its identifier (the + # <tt>id</tt> attribute). For example, <tt>#</tt><tt>page</tt>. + # * <tt>.class</tt> -- Match an element based on its class name, all + # class names if more than one specified. + # * <tt>[attr]</tt> -- Match an element that has the specified attribute. + # * <tt>[attr=value]</tt> -- Match an element that has the specified + # attribute and value. (More operators are supported see below) + # * <tt>:pseudo-class</tt> -- Match an element based on a pseudo class, + # such as <tt>:nth-child</tt> and <tt>:empty</tt>. + # * <tt>:not(expr)</tt> -- Match an element that does not match the + # negation expression. + # + # When using a combination of the above, the element name comes first + # followed by identifier, class names, attributes, pseudo classes and + # negation in any order. Do not separate these parts with spaces! + # Space separation is used for descendant selectors. + # + # For example: + # selector = HTML::Selector.new "form.login[action=/login]" + # The matched element must be of type +form+ and have the class +login+. + # It may have other classes, but the class +login+ is required to match. + # It must also have an attribute called +action+ with the value + # <tt>/login</tt>. + # + # This selector will match the following element: + # <form class="login form" method="post" action="/login"> + # but will not match the element: + # <form method="post" action="/logout"> + # + # === Attribute Values + # + # Several operators are supported for matching attributes: + # * <tt>name</tt> -- The element must have an attribute with that name. + # * <tt>name=value</tt> -- The element must have an attribute with that + # name and value. + # * <tt>name^=value</tt> -- The attribute value must start with the + # specified value. + # * <tt>name$=value</tt> -- The attribute value must end with the + # specified value. + # * <tt>name*=value</tt> -- The attribute value must contain the + # specified value. + # * <tt>name~=word</tt> -- The attribute value must contain the specified + # word (space separated). + # * <tt>name|=word</tt> -- The attribute value must start with specified + # word. + # + # For example, the following two selectors match the same element: + # #my_id + # [id=my_id] + # and so do the following two selectors: + # .my_class + # [class~=my_class] + # + # === Alternatives, siblings, children + # + # Complex selectors use a combination of expressions to match elements: + # * <tt>expr1 expr2</tt> -- Match any element against the second expression + # if it has some parent element that matches the first expression. + # * <tt>expr1 > expr2</tt> -- Match any element against the second expression + # if it is the child of an element that matches the first expression. + # * <tt>expr1 + expr2</tt> -- Match any element against the second expression + # if it immediately follows an element that matches the first expression. + # * <tt>expr1 ~ expr2</tt> -- Match any element against the second expression + # that comes after an element that matches the first expression. + # * <tt>expr1, expr2</tt> -- Match any element against the first expression, + # or against the second expression. + # + # Since children and sibling selectors may match more than one element given + # the first element, the #match method may return more than one match. + # + # === Pseudo classes + # + # Pseudo classes were introduced in CSS 3. They are most often used to select + # elements in a given position: + # * <tt>:root</tt> -- Match the element only if it is the root element + # (no parent element). + # * <tt>:empty</tt> -- Match the element only if it has no child elements, + # and no text content. + # * <tt>:content(string)</tt> -- Match the element only if it has <tt>string</tt> + # as its text content (ignoring leading and trailing whitespace). + # * <tt>:only-child</tt> -- Match the element if it is the only child (element) + # of its parent element. + # * <tt>:only-of-type</tt> -- Match the element if it is the only child (element) + # of its parent element and its type. + # * <tt>:first-child</tt> -- Match the element if it is the first child (element) + # of its parent element. + # * <tt>:first-of-type</tt> -- Match the element if it is the first child (element) + # of its parent element of its type. + # * <tt>:last-child</tt> -- Match the element if it is the last child (element) + # of its parent element. + # * <tt>:last-of-type</tt> -- Match the element if it is the last child (element) + # of its parent element of its type. + # * <tt>:nth-child(b)</tt> -- Match the element if it is the b-th child (element) + # of its parent element. The value <tt>b</tt> specifies its index, starting with 1. + # * <tt>:nth-child(an+b)</tt> -- Match the element if it is the b-th child (element) + # in each group of <tt>a</tt> child elements of its parent element. + # * <tt>:nth-child(-an+b)</tt> -- Match the element if it is the first child (element) + # in each group of <tt>a</tt> child elements, up to the first <tt>b</tt> child + # elements of its parent element. + # * <tt>:nth-child(odd)</tt> -- Match element in the odd position (i.e. first, third). + # Same as <tt>:nth-child(2n+1)</tt>. + # * <tt>:nth-child(even)</tt> -- Match element in the even position (i.e. second, + # fourth). Same as <tt>:nth-child(2n+2)</tt>. + # * <tt>:nth-of-type(..)</tt> -- As above, but only counts elements of its type. + # * <tt>:nth-last-child(..)</tt> -- As above, but counts from the last child. + # * <tt>:nth-last-of-type(..)</tt> -- As above, but counts from the last child and + # only elements of its type. + # * <tt>:not(selector)</tt> -- Match the element only if the element does not + # match the simple selector. + # + # As you can see, <tt>:nth-child<tt> pseudo class and its variant can get quite + # tricky and the CSS specification doesn't do a much better job explaining it. + # But after reading the examples and trying a few combinations, it's easy to + # figure out. + # + # For example: + # table tr:nth-child(odd) + # Selects every second row in the table starting with the first one. + # + # div p:nth-child(4) + # Selects the fourth paragraph in the +div+, but not if the +div+ contains + # other elements, since those are also counted. + # + # div p:nth-of-type(4) + # Selects the fourth paragraph in the +div+, counting only paragraphs, and + # ignoring all other elements. + # + # div p:nth-of-type(-n+4) + # Selects the first four paragraphs, ignoring all others. + # + # And you can always select an element that matches one set of rules but + # not another using <tt>:not</tt>. For example: + # p:not(.post) + # Matches all paragraphs that do not have the class <tt>.post</tt>. + # + # === Substitution Values + # + # You can use substitution with identifiers, class names and element values. + # A substitution takes the form of a question mark (<tt>?</tt>) and uses the + # next value in the argument list following the CSS expression. + # + # The substitution value may be a string or a regular expression. All other + # values are converted to strings. + # + # For example: + # selector = HTML::Selector.new "#?", /^\d+$/ + # matches any element whose identifier consists of one or more digits. + # + # See http://www.w3.org/TR/css3-selectors/ + class Selector + + + # An invalid selector. + class InvalidSelectorError < StandardError #:nodoc: + end + + + class << self + + # :call-seq: + # Selector.for_class(cls) => selector + # + # Creates a new selector for the given class name. + def for_class(cls) + self.new([".?", cls]) + end + + + # :call-seq: + # Selector.for_id(id) => selector + # + # Creates a new selector for the given id. + def for_id(id) + self.new(["#?", id]) + end + + end + + + # :call-seq: + # Selector.new(string, [values ...]) => selector + # + # Creates a new selector from a CSS 2 selector expression. + # + # The first argument is the selector expression. All other arguments + # are used for value substitution. + # + # Throws InvalidSelectorError is the selector expression is invalid. + def initialize(selector, *values) + raise ArgumentError, "CSS expression cannot be empty" if selector.empty? + @source = "" + values = values[0] if values.size == 1 && values[0].is_a?(Array) + + # We need a copy to determine if we failed to parse, and also + # preserve the original pass by-ref statement. + statement = selector.strip.dup + + # Create a simple selector, along with negation. + simple_selector(statement, values).each { |name, value| instance_variable_set("@#{name}", value) } + + @alternates = [] + @depends = nil + + # Alternative selector. + if statement.sub!(/^\s*,\s*/, "") + second = Selector.new(statement, values) + @alternates << second + # If there are alternate selectors, we group them in the top selector. + if alternates = second.instance_variable_get(:@alternates) + second.instance_variable_set(:@alternates, []) + @alternates.concat alternates + end + @source << " , " << second.to_s + # Sibling selector: create a dependency into second selector that will + # match element immediately following this one. + elsif statement.sub!(/^\s*\+\s*/, "") + second = next_selector(statement, values) + @depends = lambda do |element, first| + if element = next_element(element) + second.match(element, first) + end + end + @source << " + " << second.to_s + # Adjacent selector: create a dependency into second selector that will + # match all elements following this one. + elsif statement.sub!(/^\s*~\s*/, "") + second = next_selector(statement, values) + @depends = lambda do |element, first| + matches = [] + while element = next_element(element) + if subset = second.match(element, first) + if first && !subset.empty? + matches << subset.first + break + else + matches.concat subset + end + end + end + matches.empty? ? nil : matches + end + @source << " ~ " << second.to_s + # Child selector: create a dependency into second selector that will + # match a child element of this one. + elsif statement.sub!(/^\s*>\s*/, "") + second = next_selector(statement, values) + @depends = lambda do |element, first| + matches = [] + element.children.each do |child| + if child.tag? && subset = second.match(child, first) + if first && !subset.empty? + matches << subset.first + break + else + matches.concat subset + end + end + end + matches.empty? ? nil : matches + end + @source << " > " << second.to_s + # Descendant selector: create a dependency into second selector that + # will match all descendant elements of this one. Note, + elsif statement =~ /^\s+\S+/ && statement != selector + second = next_selector(statement, values) + @depends = lambda do |element, first| + matches = [] + stack = element.children.reverse + while node = stack.pop + next unless node.tag? + if subset = second.match(node, first) + if first && !subset.empty? + matches << subset.first + break + else + matches.concat subset + end + elsif children = node.children + stack.concat children.reverse + end + end + matches.empty? ? nil : matches + end + @source << " " << second.to_s + else + # The last selector is where we check that we parsed + # all the parts. + unless statement.empty? || statement.strip.empty? + raise ArgumentError, "Invalid selector: #{statement}" + end + end + end + + + # :call-seq: + # match(element, first?) => array or nil + # + # Matches an element against the selector. + # + # For a simple selector this method returns an array with the + # element if the element matches, nil otherwise. + # + # For a complex selector (sibling and descendant) this method + # returns an array with all matching elements, nil if no match is + # found. + # + # Use +first_only=true+ if you are only interested in the first element. + # + # For example: + # if selector.match(element) + # puts "Element is a login form" + # end + def match(element, first_only = false) + # Match element if no element name or element name same as element name + if matched = (!@tag_name || @tag_name == element.name) + # No match if one of the attribute matches failed + for attr in @attributes + if element.attributes[attr[0]] !~ attr[1] + matched = false + break + end + end + end + + # Pseudo class matches (nth-child, empty, etc). + if matched + for pseudo in @pseudo + unless pseudo.call(element) + matched = false + break + end + end + end + + # Negation. Same rules as above, but we fail if a match is made. + if matched && @negation + for negation in @negation + if negation[:tag_name] == element.name + matched = false + else + for attr in negation[:attributes] + if element.attributes[attr[0]] =~ attr[1] + matched = false + break + end + end + end + if matched + for pseudo in negation[:pseudo] + if pseudo.call(element) + matched = false + break + end + end + end + break unless matched + end + end + + # If element matched but depends on another element (child, + # sibling, etc), apply the dependent matches instead. + if matched && @depends + matches = @depends.call(element, first_only) + else + matches = matched ? [element] : nil + end + + # If this selector is part of the group, try all the alternative + # selectors (unless first_only). + if !first_only || !matches + @alternates.each do |alternate| + break if matches && first_only + if subset = alternate.match(element, first_only) + if matches + matches.concat subset + else + matches = subset + end + end + end + end + + matches + end + + + # :call-seq: + # select(root) => array + # + # Selects and returns an array with all matching elements, beginning + # with one node and traversing through all children depth-first. + # Returns an empty array if no match is found. + # + # The root node may be any element in the document, or the document + # itself. + # + # For example: + # selector = HTML::Selector.new "input[type=text]" + # matches = selector.select(element) + # matches.each do |match| + # puts "Found text field with name #{match.attributes['name']}" + # end + def select(root) + matches = [] + stack = [root] + while node = stack.pop + if node.tag? && subset = match(node, false) + subset.each do |match| + matches << match unless matches.any? { |item| item.equal?(match) } + end + elsif children = node.children + stack.concat children.reverse + end + end + matches + end + + + # Similar to #select but returns the first matching element. Returns +nil+ + # if no element matches the selector. + def select_first(root) + stack = [root] + while node = stack.pop + if node.tag? && subset = match(node, true) + return subset.first if !subset.empty? + elsif children = node.children + stack.concat children.reverse + end + end + nil + end + + + def to_s #:nodoc: + @source + end + + + # Return the next element after this one. Skips sibling text nodes. + # + # With the +name+ argument, returns the next element with that name, + # skipping other sibling elements. + def next_element(element, name = nil) + if siblings = element.parent.children + found = false + siblings.each do |node| + if node.equal?(element) + found = true + elsif found && node.tag? + return node if (name.nil? || node.name == name) + end + end + end + nil + end + + + protected + + + # Creates a simple selector given the statement and array of + # substitution values. + # + # Returns a hash with the values +tag_name+, +attributes+, + # +pseudo+ (classes) and +negation+. + # + # Called the first time with +can_negate+ true to allow + # negation. Called a second time with false since negation + # cannot be negated. + def simple_selector(statement, values, can_negate = true) + tag_name = nil + attributes = [] + pseudo = [] + negation = [] + + # Element name. (Note that in negation, this can come at + # any order, but for simplicity we allow if only first). + statement.sub!(/^(\*|[[:alpha:]][\w\-]*)/) do |match| + match.strip! + tag_name = match.downcase unless match == "*" + @source << match + "" # Remove + end + + # Get identifier, class, attribute name, pseudo or negation. + while true + # Element identifier. + next if statement.sub!(/^#(\?|[\w\-]+)/) do |match| + id = $1 + if id == "?" + id = values.shift + end + @source << "##{id}" + id = Regexp.new("^#{Regexp.escape(id.to_s)}$") unless id.is_a?(Regexp) + attributes << ["id", id] + "" # Remove + end + + # Class name. + next if statement.sub!(/^\.([\w\-]+)/) do |match| + class_name = $1 + @source << ".#{class_name}" + class_name = Regexp.new("(^|\s)#{Regexp.escape(class_name)}($|\s)") unless class_name.is_a?(Regexp) + attributes << ["class", class_name] + "" # Remove + end + + # Attribute value. + next if statement.sub!(/^\[\s*([[:alpha:]][\w\-:]*)\s*((?:[~|^$*])?=)?\s*('[^']*'|"[^*]"|[^\]]*)\s*\]/) do |match| + name, equality, value = $1, $2, $3 + if value == "?" + value = values.shift + else + # Handle single and double quotes. + value.strip! + if (value[0] == ?" || value[0] == ?') && value[0] == value[-1] + value = value[1..-2] + end + end + @source << "[#{name}#{equality}'#{value}']" + attributes << [name.downcase.strip, attribute_match(equality, value)] + "" # Remove + end + + # Root element only. + next if statement.sub!(/^:root/) do |match| + pseudo << lambda do |element| + element.parent.nil? || !element.parent.tag? + end + @source << ":root" + "" # Remove + end + + # Nth-child including last and of-type. + next if statement.sub!(/^:nth-(last-)?(child|of-type)\((odd|even|(\d+|\?)|(-?\d*|\?)?n([+\-]\d+|\?)?)\)/) do |match| + reverse = $1 == "last-" + of_type = $2 == "of-type" + @source << ":nth-#{$1}#{$2}(" + case $3 + when "odd" + pseudo << nth_child(2, 1, of_type, reverse) + @source << "odd)" + when "even" + pseudo << nth_child(2, 2, of_type, reverse) + @source << "even)" + when /^(\d+|\?)$/ # b only + b = ($1 == "?" ? values.shift : $1).to_i + pseudo << nth_child(0, b, of_type, reverse) + @source << "#{b})" + when /^(-?\d*|\?)?n([+\-]\d+|\?)?$/ + a = ($1 == "?" ? values.shift : + $1 == "" ? 1 : $1 == "-" ? -1 : $1).to_i + b = ($2 == "?" ? values.shift : $2).to_i + pseudo << nth_child(a, b, of_type, reverse) + @source << (b >= 0 ? "#{a}n+#{b})" : "#{a}n#{b})") + else + raise ArgumentError, "Invalid nth-child #{match}" + end + "" # Remove + end + # First/last child (of type). + next if statement.sub!(/^:(first|last)-(child|of-type)/) do |match| + reverse = $1 == "last" + of_type = $2 == "of-type" + pseudo << nth_child(0, 1, of_type, reverse) + @source << ":#{$1}-#{$2}" + "" # Remove + end + # Only child (of type). + next if statement.sub!(/^:only-(child|of-type)/) do |match| + of_type = $1 == "of-type" + pseudo << only_child(of_type) + @source << ":only-#{$1}" + "" # Remove + end + + # Empty: no child elements or meaningful content (whitespaces + # are ignored). + next if statement.sub!(/^:empty/) do |match| + pseudo << lambda do |element| + empty = true + for child in element.children + if child.tag? || !child.content.strip.empty? + empty = false + break + end + end + empty + end + @source << ":empty" + "" # Remove + end + # Content: match the text content of the element, stripping + # leading and trailing spaces. + next if statement.sub!(/^:content\(\s*(\?|'[^']*'|"[^"]*"|[^)]*)\s*\)/) do |match| + content = $1 + if content == "?" + content = values.shift + elsif (content[0] == ?" || content[0] == ?') && content[0] == content[-1] + content = content[1..-2] + end + @source << ":content('#{content}')" + content = Regexp.new("^#{Regexp.escape(content.to_s)}$") unless content.is_a?(Regexp) + pseudo << lambda do |element| + text = "" + for child in element.children + unless child.tag? + text << child.content + end + end + text.strip =~ content + end + "" # Remove + end + + # Negation. Create another simple selector to handle it. + if statement.sub!(/^:not\(\s*/, "") + raise ArgumentError, "Double negatives are not missing feature" unless can_negate + @source << ":not(" + negation << simple_selector(statement, values, false) + raise ArgumentError, "Negation not closed" unless statement.sub!(/^\s*\)/, "") + @source << ")" + next + end + + # No match: moving on. + break + end + + # Return hash. The keys are mapped to instance variables. + {:tag_name=>tag_name, :attributes=>attributes, :pseudo=>pseudo, :negation=>negation} + end + + + # Create a regular expression to match an attribute value based + # on the equality operator (=, ^=, |=, etc). + def attribute_match(equality, value) + regexp = value.is_a?(Regexp) ? value : Regexp.escape(value.to_s) + case equality + when "=" then + # Match the attribute value in full + Regexp.new("^#{regexp}$") + when "~=" then + # Match a space-separated word within the attribute value + Regexp.new("(^|\s)#{regexp}($|\s)") + when "^=" + # Match the beginning of the attribute value + Regexp.new("^#{regexp}") + when "$=" + # Match the end of the attribute value + Regexp.new("#{regexp}$") + when "*=" + # Match substring of the attribute value + regexp.is_a?(Regexp) ? regexp : Regexp.new(regexp) + when "|=" then + # Match the first space-separated item of the attribute value + Regexp.new("^#{regexp}($|\s)") + else + raise InvalidSelectorError, "Invalid operation/value" unless value.empty? + # Match all attributes values (existence check) + // + end + end + + + # Returns a lambda that can match an element against the nth-child + # pseudo class, given the following arguments: + # * +a+ -- Value of a part. + # * +b+ -- Value of b part. + # * +of_type+ -- True to test only elements of this type (of-type). + # * +reverse+ -- True to count in reverse order (last-). + def nth_child(a, b, of_type, reverse) + # a = 0 means select at index b, if b = 0 nothing selected + return lambda { |element| false } if a == 0 && b == 0 + # a < 0 and b < 0 will never match against an index + return lambda { |element| false } if a < 0 && b < 0 + b = a + b + 1 if b < 0 # b < 0 just picks last element from each group + b -= 1 unless b == 0 # b == 0 is same as b == 1, otherwise zero based + lambda do |element| + # Element must be inside parent element. + return false unless element.parent && element.parent.tag? + index = 0 + # Get siblings, reverse if counting from last. + siblings = element.parent.children + siblings = siblings.reverse if reverse + # Match element name if of-type, otherwise ignore name. + name = of_type ? element.name : nil + found = false + for child in siblings + # Skip text nodes/comments. + if child.tag? && (name == nil || child.name == name) + if a == 0 + # Shortcut when a == 0 no need to go past count + if index == b + found = child.equal?(element) + break + end + elsif a < 0 + # Only look for first b elements + break if index > b + if child.equal?(element) + found = (index % a) == 0 + break + end + else + # Otherwise, break if child found and count == an+b + if child.equal?(element) + found = (index % a) == b + break + end + end + index += 1 + end + end + found + end + end + + + # Creates a only child lambda. Pass +of-type+ to only look at + # elements of its type. + def only_child(of_type) + lambda do |element| + # Element must be inside parent element. + return false unless element.parent && element.parent.tag? + name = of_type ? element.name : nil + other = false + for child in element.parent.children + # Skip text nodes/comments. + if child.tag? && (name == nil || child.name == name) + unless child.equal?(element) + other = true + break + end + end + end + !other + end + end + + + # Called to create a dependent selector (sibling, descendant, etc). + # Passes the remainder of the statement that will be reduced to zero + # eventually, and array of substitution values. + # + # This method is called from four places, so it helps to put it here + # for reuse. The only logic deals with the need to detect comma + # separators (alternate) and apply them to the selector group of the + # top selector. + def next_selector(statement, values) + second = Selector.new(statement, values) + # If there are alternate selectors, we group them in the top selector. + if alternates = second.instance_variable_get(:@alternates) + second.instance_variable_set(:@alternates, []) + @alternates.concat alternates + end + second + end + + end + + + # See HTML::Selector.new + def self.selector(statement, *values) + Selector.new(statement, *values) + end + + + class Tag + + def select(selector, *values) + selector = HTML::Selector.new(selector, values) + selector.select(self) + end + + end + +end |