Class: Liquid::Strainer

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

Overview

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

Constant Summary collapse

@@global_strainer =

:nodoc:

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context) ⇒ Strainer

Returns a new instance of Strainer.



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# File 'lib/liquid/strainer.rb', line 21

def initialize(context)
  @context = context
end

Class Method Details

.add_filter(filter) ⇒ Object

Raises:



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# File 'lib/liquid/strainer.rb', line 29

def self.add_filter(filter)
  raise ArgumentError, "Expected module but got: #{f.class}" unless filter.is_a?(Module)
  unless self.class.include?(filter)
    self.send(:include, filter)
    @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
  end
end

.create(context, filters = []) ⇒ Object 



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# File 'lib/liquid/strainer.rb', line 45

def self.create(context, filters = [])
  @@strainer_class_cache[filters].new(context)
end

.filter_methods ⇒ Object 



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# File 'lib/liquid/strainer.rb', line 25

def self.filter_methods
  @filter_methods
end

.global_filter(filter) ⇒ Object 



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# File 'lib/liquid/strainer.rb', line 37

def self.global_filter(filter)
  @@global_strainer.add_filter(filter)
end

.invokable?(method) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/liquid/strainer.rb', line 41

def self.invokable?(method)
  @filter_methods.include?(method.to_s)
end

Instance Method Details

#invoke(method, *args) ⇒ Object 



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# File 'lib/liquid/strainer.rb', line 49

def invoke(method, *args)
  if self.class.invokable?(method)
    send(method, *args)
  else
    args.first
  end
rescue ::ArgumentError => e
  raise Liquid::ArgumentError.new(e.message)
end