Class: Liquid::Expression

Inherits:
Object
  • Object
show all
Defined in:
lib/liquid/expression.rb

Constant Summary collapse

LITERALS = 
{
  nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
  'true' => true,
  'false' => false,
  'blank' => '',
  'empty' => ''
}.freeze
SINGLE_QUOTED_STRING = 
/\A\s*'(.*)'\s*\z/m
DOUBLE_QUOTED_STRING = 
/\A\s*"(.*)"\s*\z/m
INTEGERS_REGEX = 
/\A\s*(-?\d+)\s*\z/
FLOATS_REGEX = 
/\A\s*(-?\d[\d\.]+)\s*\z/
RANGES_REGEX =

Use an atomic group (?>…) to avoid pathological backtracing from malicious input as described in github.com/Shopify/liquid/issues/1357

/\A\s*\(\s*(?>(\S+)\s*\.\.)\s*(\S+)\s*\)\s*\z/

Class Method Summary collapse

Class Method Details

.parse(markup) ⇒ Object 



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# File 'lib/liquid/expression.rb', line 22

def self.parse(markup)
  case markup
  when nil
    nil
  when SINGLE_QUOTED_STRING, DOUBLE_QUOTED_STRING
    Regexp.last_match(1)
  when INTEGERS_REGEX
    Regexp.last_match(1).to_i
  when RANGES_REGEX
    RangeLookup.parse(Regexp.last_match(1), Regexp.last_match(2))
  when FLOATS_REGEX
    Regexp.last_match(1).to_f
  else
    markup = markup.strip
    if LITERALS.key?(markup)
      LITERALS[markup]
    else
      VariableLookup.parse(markup)
    end
  end
end