diff options
Diffstat (limited to 'actionview/lib/action_view/vendor/html-scanner/html/selector.rb')
| -rw-r--r-- | actionview/lib/action_view/vendor/html-scanner/html/selector.rb | 830 |
1 files changed, 0 insertions, 830 deletions
diff --git a/actionview/lib/action_view/vendor/html-scanner/html/selector.rb b/actionview/lib/action_view/vendor/html-scanner/html/selector.rb deleted file mode 100644 index dfdd724b9b..0000000000 --- a/actionview/lib/action_view/vendor/html-scanner/html/selector.rb +++ /dev/null @@ -1,830 +0,0 @@ -#-- -# 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 - - - # Returns 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 |