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https://github.com/Shopify/liquid.git
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Tobi Lutke
33bac87a5c
Implement ActiveSupport-compatible behaviors internally so Liquid works
correctly without ActiveSupport being loaded:
1. String first/last via property access (name.first, name.last)
- VariableLookup now handles string[0] and string[-1] for first/last
2. String first/last via filters (name | first, name | last)
- StandardFilters#first and #last now handle strings
3. blank?/empty? comparisons for types without these methods
- Condition now implements liquid_blank? and liquid_empty? internally
- blank? matches ActiveSupport: nil, false, empty/whitespace strings,
empty arrays/hashes are all blank
- empty? checks length == 0 only (whitespace is NOT empty)
This fixes spec failures for templates like:
- {{ name.first }} / {{ name | first }} on strings
- {% if x == blank %} for whitespace strings, empty hashes/arrays
- {% case ' ' %}{% when blank %} matching whitespace
109 lines
3.3 KiB
Ruby
109 lines
3.3 KiB
Ruby
# frozen_string_literal: true
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module Liquid
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class VariableLookup
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COMMAND_METHODS = ['size', 'first', 'last'].freeze
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attr_reader :name, :lookups
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def self.parse(markup, string_scanner = StringScanner.new(""), cache = nil)
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new(markup, string_scanner, cache)
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end
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def initialize(markup, string_scanner = StringScanner.new(""), cache = nil)
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lookups = markup.scan(VariableParser)
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name = lookups.shift
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if name&.start_with?('[') && name&.end_with?(']')
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name = Expression.parse(
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name[1..-2],
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string_scanner,
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cache,
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)
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end
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@name = name
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@lookups = lookups
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@command_flags = 0
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@lookups.each_index do |i|
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lookup = lookups[i]
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if lookup&.start_with?('[') && lookup&.end_with?(']')
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lookups[i] = Expression.parse(
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lookup[1..-2],
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string_scanner,
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cache,
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)
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elsif COMMAND_METHODS.include?(lookup)
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@command_flags |= 1 << i
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end
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end
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end
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def lookup_command?(lookup_index)
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@command_flags & (1 << lookup_index) != 0
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end
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def evaluate(context)
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name = context.evaluate(@name)
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object = context.find_variable(name)
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@lookups.each_index do |i|
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key = context.evaluate(@lookups[i])
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# Cast "key" to its liquid value to enable it to act as a primitive value
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key = Liquid::Utils.to_liquid_value(key)
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# If object is a hash- or array-like object we look for the
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# presence of the key and if its available we return it
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if object.respond_to?(:[]) &&
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((object.respond_to?(:key?) && object.key?(key)) ||
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(object.respond_to?(:fetch) && key.is_a?(Integer)))
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# if its a proc we will replace the entry with the proc
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res = context.lookup_and_evaluate(object, key)
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object = res.to_liquid
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# Some special cases. If the part wasn't in square brackets and
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# no key with the same name was found we interpret following calls
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# as commands and call them on the current object
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elsif lookup_command?(i) && object.respond_to?(key)
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object = object.send(key).to_liquid
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# Handle string first/last like ActiveSupport does (returns first/last character)
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elsif lookup_command?(i) && object.is_a?(String) && (key == "first" || key == "last")
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object = key == "first" ? object[0] : object[-1]
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# No key was present with the desired value and it wasn't one of the directly supported
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# keywords either. The only thing we got left is to return nil or
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# raise an exception if `strict_variables` option is set to true
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else
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return nil unless context.strict_variables
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raise Liquid::UndefinedVariable, "undefined variable #{key}"
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end
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# If we are dealing with a drop here we have to
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object.context = context if object.respond_to?(:context=)
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end
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object
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end
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def ==(other)
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self.class == other.class && state == other.state
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end
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protected
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def state
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[@name, @lookups, @command_flags]
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end
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class ParseTreeVisitor < Liquid::ParseTreeVisitor
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def children
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@node.lookups
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end
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end
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end
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end
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