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Refactor expand_font_shorthand
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I used https://www.w3.org/TR/CSS21/fonts.html#propdef-font to create the scanner
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@stoivo
stoivo committed May 29, 2024
1 parent bef5a63 commit cb93ddc
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Showing 3 changed files with 148 additions and 45 deletions.
1 change: 0 additions & 1 deletion lib/css_parser/regexps.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,6 @@ def self.regex_possible_values(*values)
RE_SINGLE_BACKGROUND_SIZE = /#{RE_LENGTH_OR_PERCENTAGE}|auto|cover|contain|initial|inherit/i.freeze
RE_BACKGROUND_POSITION = /#{RE_SINGLE_BACKGROUND_POSITION}\s+#{RE_SINGLE_BACKGROUND_POSITION}|#{RE_SINGLE_BACKGROUND_POSITION}/.freeze
RE_BACKGROUND_SIZE = %r{\s*/\s*(#{RE_SINGLE_BACKGROUND_SIZE}\s+#{RE_SINGLE_BACKGROUND_SIZE}|#{RE_SINGLE_BACKGROUND_SIZE})}.freeze
FONT_UNITS_RX = /((x+-)*small|medium|larger*|auto|inherit|([0-9]+|[0-9]*\.[0-9]+)(e[mx]+|px|[cm]+m|p[tc+]|in|%)*)/i.freeze
RE_BORDER_STYLE = /(\s*^)?(none|hidden|dotted|dashed|solid|double|dot-dash|dot-dot-dash|wave|groove|ridge|inset|outset)(\s*$)?/imx.freeze
RE_BORDER_UNITS = Regexp.union(BOX_MODEL_UNITS_RX, /(thin|medium|thick)/i)

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152 changes: 119 additions & 33 deletions lib/css_parser/rule_set.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -203,6 +203,94 @@ def expand_dimensions_shorthand! # :nodoc:
end
end

class FontScanner
FONT_STYLES = Set.new(["normal", "italic", "oblique", "inherit"])
FONT_VARIANTS = Set.new(["normal", "small-caps", "inherit"])
FONT_WEIGHTS = Set.new([
"normal","bold","bolder","lighter",
"100","200","300","400","500","600","700","800","900",
"inherit"
])
ABSOLUTE_SIZES = Set
.new(["xx-small", "x-small", "small", "medium", "large", "x-large", "xx-large", ])
RELATIVE_SIZES = Set.new(["smaller", "larger",])

attr_reader :current, :pos, :tokens

def initialize(tokens)
@token_scanner = Crass::TokenScanner.new(tokens)
end

def peek = @token_scanner.peek
def consume = @token_scanner.consume
def collect(&block) = @token_scanner.collect(&block)

private def consume_iden_str value
if peek[:node] == :ident && peek[:value] == value
return consume
else
nil
end
end

private def consume_iden_set set
if peek[:node] == :ident && set.member?(peek[:value])
return consume
else
nil
end
end

private def consume_type type
if peek[:node] == type
return consume
else
nil
end
end

def consume_font_style = consume_iden_set(FONT_STYLES)
def consume_font_variant = consume_iden_set(FONT_VARIANTS)
def consume_font_weight = consume_iden_set(FONT_WEIGHTS) || consume_type(:number)
def consume_absulute_size = consume_iden_set(ABSOLUTE_SIZES)
def consume_relative_size = consume_iden_set(RELATIVE_SIZES)
def consume_length = consume_type(:dimension)
def consume_percentage = consume_type(:percentage)
def consume_number = consume_type(:percentage)
def consume_inherit = consume_iden_str("inherit")
def consume_normal = consume_iden_str("normal")

def consume_font_style_variant_weight
consume_font_style || consume_font_variant || consume_font_weight
end

def consume_font_size
consume_absulute_size ||
consume_relative_size ||
consume_length ||
consume_percentage ||
consume_inherit
end

def consume_line_height
consume_normal ||
consume_number ||
consume_length ||
consume_percentage ||
consume_inherit
end

def consume_system_fonts
consume_iden_str("caption") ||
consume_iden_str("icon") ||
consume_iden_str("menu") ||
consume_iden_str("message-box") ||
consume_iden_str("small-caption") ||
consume_iden_str("status-bar") ||
consume_inherit
end
end

# Convert shorthand font declarations (e.g. <tt>font: 300 italic 11px/14px verdana, helvetica, sans-serif;</tt>)
# into their constituent parts.
def expand_font_shorthand! # :nodoc:
Expand All @@ -216,41 +304,39 @@ def expand_font_shorthand! # :nodoc:
'font-size' => 'normal',
'line-height' => 'normal'
}
tokens = Crass::Tokenizer.tokenize(declaration.value.dup)
.reject { _1[:node] == :whitespace }
scanner = FontScanner.new(tokens)

value = declaration.value.dup
value.gsub!(%r{/\s+}, '/') # handle spaces between font size and height shorthand (e.g. 14px/ 16px)

in_fonts = false

matches = value.scan(/"(?:.*[^"])"|'(?:.*[^'])'|(?:\w[^ ,]+)/)
matches.each do |m|
m.strip!
m.gsub!(/;$/, '')

if in_fonts
if font_props.key?('font-family')
font_props['font-family'] += ", #{m}"
else
font_props['font-family'] = m
end
elsif m =~ /normal|inherit/i
['font-style', 'font-weight', 'font-variant'].each do |font_prop|
font_props[font_prop] ||= m
end
elsif m =~ /italic|oblique/i
font_props['font-style'] = m
elsif m =~ /small-caps/i
font_props['font-variant'] = m
elsif m =~ /[1-9]00$|bold|bolder|lighter/i
font_props['font-weight'] = m
elsif m =~ CssParser::FONT_UNITS_RX
if m.include?('/')
font_props['font-size'], font_props['line-height'] = m.split('/', 2)
else
font_props['font-size'] = m
end
in_fonts = true
while token = scanner.consume_font_style_variant_weight
if FontScanner::FONT_STYLES.member?(token[:value])
font_props["font-style"] = token[:value]
end
if FontScanner::FONT_VARIANTS.member?(token[:value])
font_props["font-variant"] = token[:value]
end
# we use raw from font wights since it include numbers
if FontScanner::FONT_WEIGHTS.member?(token[:raw])
font_props["font-weight"] = token[:raw]
end
end

font_size = scanner.consume_font_size
font_props["font-size"] = font_size[:raw]

if scanner.peek[:node] == :delim && scanner.peek[:value] == "/"
scanner.consume
line_height = scanner.consume_line_height
font_props["line-height"] = line_height[:raw]
end

rest = scanner.collect {
while scanner.consume
# nothing, just collect the rest
end
}
if rest.any?
font_props["font-family"] = Crass::Parser.stringify(rest)
end

declarations.replace_declaration!('font', font_props, preserve_importance: true)
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40 changes: 29 additions & 11 deletions test/test_rule_set_expanding_shorthand.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -71,20 +71,26 @@ def test_getting_font_size_from_shorthand
['em', 'ex', 'in', 'px', 'pt', 'pc', '%'].each do |unit|
shorthand = "font: 300 italic 11.25#{unit}/14px verdana, helvetica, sans-serif;"
declarations = expand_declarations(shorthand)
assert_equal("11.25#{unit}", declarations['font-size'])
assert_equal("11.25#{unit}", declarations['font-size'], shorthand)
end

['smaller', 'small', 'medium', 'large', 'x-large'].each do |unit|
shorthand = "font: 300 italic #{unit}/14px verdana, helvetica, sans-serif;"
declarations = expand_declarations(shorthand)
assert_equal(unit, declarations['font-size'])
assert_equal(unit, declarations['font-size'], shorthand)
end
end

def test_font_with_comments_and_spaces
shorthand = "font: 300 /* HI */ italic \t\t 12px sans-serif;"
declarations = expand_declarations(shorthand)
assert_equal("12px", declarations['font-size'])
end

def test_getting_font_families_from_shorthand
shorthand = "font: 300 italic 12px/14px \"Helvetica-Neue-Light 45\", 'verdana', helvetica, sans-serif;"
declarations = expand_declarations(shorthand)
assert_equal("\"Helvetica-Neue-Light 45\", 'verdana', helvetica, sans-serif", declarations['font-family'])
assert_equal("\"Helvetica-Neue-Light 45\",'verdana',helvetica,sans-serif", declarations['font-family'])
end

def test_getting_font_weight_from_shorthand
Expand All @@ -95,8 +101,11 @@ def test_getting_font_weight_from_shorthand
end

# ensure normal is the default state
['font: normal italic 12px sans-serif;', 'font: italic 12px sans-serif;',
'font: small-caps normal 12px sans-serif;', 'font: 12px/16px sans-serif;'].each do |shorthand|
[ 'font: normal italic 12px sans-serif;',
'font: italic 12px sans-serif;',
'font: small-caps normal 12px sans-serif;',
'font: 12px/16px sans-serif;'
].each do |shorthand|
declarations = expand_declarations(shorthand)
assert_equal('normal', declarations['font-weight'], shorthand)
end
Expand All @@ -110,8 +119,11 @@ def test_getting_font_variant_from_shorthand

def test_getting_font_variant_from_shorthand_ensure_normal_is_the_default_state
[
'font: normal italic 12px sans-serif;', 'font: italic 12px sans-serif;',
'font: normal 12px sans-serif;', 'font: 12px/16px sans-serif;'
'font: normal large sans-serif;',
'font: normal italic 12px sans-serif;',
'font: italic 12px sans-serif;',
'font: normal 12px sans-serif;',
'font: 12px/16px sans-serif;'
].each do |shorthand|
declarations = expand_declarations(shorthand)
assert_equal('normal', declarations['font-variant'], shorthand)
Expand All @@ -126,8 +138,11 @@ def test_getting_font_style_from_shorthand
end

# ensure normal is the default state
['font: normal bold 12px sans-serif;', 'font: small-caps 12px sans-serif;',
'font: normal 12px sans-serif;', 'font: 12px/16px sans-serif;'].each do |shorthand|
['font: normal bold 12px sans-serif;',
'font: small-caps 12px sans-serif;',
'font: normal 12px sans-serif;',
'font: 12px/16px sans-serif;'
].each do |shorthand|
declarations = expand_declarations(shorthand)
assert_equal('normal', declarations['font-style'], shorthand)
end
Expand All @@ -141,8 +156,11 @@ def test_getting_line_height_from_shorthand
end

# ensure normal is the default state
['font: normal bold 12px sans-serif;', 'font: small-caps 12px sans-serif;',
'font: normal 12px sans-serif;', 'font: 12px sans-serif;'].each do |shorthand|
['font: normal bold 12px sans-serif;',
'font: small-caps 12px sans-serif;',
'font: normal 12px sans-serif;',
'font: 12px sans-serif;'
].each do |shorthand|
declarations = expand_declarations(shorthand)
assert_equal('normal', declarations['line-height'], shorthand)
end
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