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# frozen_string_literal: true
require 'addressable/uri'
require 'uri'
require 'net/https'
require 'digest/md5'
require 'zlib'
require 'stringio'
require 'css_parser/version'
require 'css_parser/rule_set'
require 'css_parser/regexps'
require 'css_parser/parser'
module CssParser
# Merge multiple CSS RuleSets by cascading according to the CSS 2.1 cascading rules
# (http://www.w3.org/TR/REC-CSS2/cascade.html#cascading-order).
#
# Takes one or more RuleSet objects.
#
# Returns a RuleSet.
#
# ==== Cascading
# If a RuleSet object has its +specificity+ defined, that specificity is
# used in the cascade calculations.
#
# If no specificity is explicitly set and the RuleSet has *one* selector,
# the specificity is calculated using that selector.
#
# If no selectors the specificity is treated as 0.
#
# If multiple selectors are present then the greatest specificity is used.
#
# ==== Example #1
# rs1 = RuleSet.new(nil, 'color: black;')
# rs2 = RuleSet.new(nil, 'margin: 0px;')
#
# merged = CssParser.merge(rs1, rs2)
#
# puts merged
# => "{ margin: 0px; color: black; }"
#
# ==== Example #2
# rs1 = RuleSet.new(nil, 'background-color: black;')
# rs2 = RuleSet.new(nil, 'background-image: none;')
#
# merged = CssParser.merge(rs1, rs2)
#
# puts merged
# => "{ background: none black; }"
#--
# TODO: declaration_hashes should be able to contain a RuleSet
# this should be a Class method
def self.merge(*rule_sets)
@folded_declaration_cache = {}
# in case called like CssParser.merge([rule_set, rule_set])
rule_sets.flatten! if rule_sets[0].is_a?(Array)
unless rule_sets.all?(CssParser::RuleSet)
raise ArgumentError, 'all parameters must be CssParser::RuleSets.'
end
return rule_sets[0] if rule_sets.length == 1
# Internal storage of CSS properties that we will keep
properties = {}
rule_sets.each do |rule_set|
rule_set.expand_shorthand!
specificity = rule_set.specificity
specificity ||= rule_set.selectors.filter_map { |s| calculate_specificity(s) }.max || 0
rule_set.each_declaration do |property, value, is_important|
# Add the property to the list to be folded per http://www.w3.org/TR/CSS21/cascade.html#cascading-order
if !properties.key?(property)
properties[property] = {value: value, specificity: specificity, is_important: is_important}
elsif is_important
if !properties[property][:is_important] || properties[property][:specificity] <= specificity
properties[property] = {value: value, specificity: specificity, is_important: is_important}
end
elsif properties[property][:specificity] < specificity || properties[property][:specificity] == specificity
unless properties[property][:is_important]
properties[property] = {value: value, specificity: specificity, is_important: is_important}
end
end
end
end
merged = properties.each_with_object(RuleSet.new(nil, nil)) do |(property, details), rule_set|
value = details[:value].strip
rule_set[property.strip] = details[:is_important] ? "#{value.gsub(/;\Z/, '')}!important" : value
end
merged.create_shorthand!
merged
end
# Calculates the specificity of a CSS selector
# per http://www.w3.org/TR/CSS21/cascade.html#specificity
#
# Returns an integer.
#
# ==== Example
# CssParser.calculate_specificity('#content div p:first-line a:link')
# => 114
#--
# Thanks to Rafael Salazar and Nick Fitzsimons on the css-discuss list for their help.
#++
def self.calculate_specificity(selector)
a = 0
b = selector.scan('#').length
c = selector.scan(NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX_NC).length
d = selector.scan(ELEMENTS_AND_PSEUDO_ELEMENTS_RX_NC).length
"#{a}#{b}#{c}#{d}".to_i
rescue
0
end
# Make <tt>url()</tt> links absolute.
#
# Takes a block of CSS and returns it with all relative URIs converted to absolute URIs.
#
# "For CSS style sheets, the base URI is that of the style sheet, not that of the source document."
# per http://www.w3.org/TR/CSS21/syndata.html#uri
#
# Returns a string.
#
# ==== Example
# CssParser.convert_uris("body { background: url('../style/yellow.png?abc=123') };",
# "http://example.org/style/basic.css").inspect
# => "body { background: url('http://example.org/style/yellow.png?abc=123') };"
def self.convert_uris(css, base_uri)
base_uri = Addressable::URI.parse(base_uri) unless base_uri.is_a?(Addressable::URI)
css.gsub(URI_RX) do
uri = Regexp.last_match(1).to_s.gsub(/["']+/, '')
# Don't process URLs that are already absolute
unless uri.match?(%r{^[a-z]+://}i)
begin
uri = base_uri.join(uri)
rescue
nil
end
end
"url('#{uri}')"
end
end
def self.sanitize_media_query(raw)
mq = raw.to_s.gsub(/\s+/, ' ')
mq.strip!
mq = 'all' if mq.empty?
mq.to_sym
end
end
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