rf-web/vendor/bundle/gems/liquid-4.0.3/lib/liquid/strainer.rb

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2019-10-21 08:18:17 +00:00
require 'set'
module Liquid
# Strainer is the parent class for the filters system.
# New filters are mixed into the strainer class which is then instantiated for each liquid template render run.
#
# The Strainer only allows method calls defined in filters given to it via Strainer.global_filter,
# Context#add_filters or Template.register_filter
class Strainer #:nodoc:
@@global_strainer = Class.new(Strainer) do
@filter_methods = Set.new
end
@@strainer_class_cache = Hash.new do |hash, filters|
hash[filters] = Class.new(@@global_strainer) do
@filter_methods = @@global_strainer.filter_methods.dup
filters.each { |f| add_filter(f) }
end
end
def initialize(context)
@context = context
end
class << self
attr_reader :filter_methods
end
def self.add_filter(filter)
raise ArgumentError, "Expected module but got: #{filter.class}" unless filter.is_a?(Module)
unless self.include?(filter)
invokable_non_public_methods = (filter.private_instance_methods + filter.protected_instance_methods).select { |m| invokable?(m) }
if invokable_non_public_methods.any?
raise MethodOverrideError, "Filter overrides registered public methods as non public: #{invokable_non_public_methods.join(', ')}"
else
send(:include, filter)
@filter_methods.merge(filter.public_instance_methods.map(&:to_s))
end
end
end
def self.global_filter(filter)
@@strainer_class_cache.clear
@@global_strainer.add_filter(filter)
end
def self.invokable?(method)
@filter_methods.include?(method.to_s)
end
def self.create(context, filters = [])
@@strainer_class_cache[filters].new(context)
end
def invoke(method, *args)
if self.class.invokable?(method)
send(method, *args)
elsif @context && @context.strict_filters
raise Liquid::UndefinedFilter, "undefined filter #{method}"
else
args.first
end
rescue ::ArgumentError => e
raise Liquid::ArgumentError, e.message, e.backtrace
end
end
end