2011-12-06 20:05:31 +00:00
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require 'set'
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module Docile
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class FallbackContextProxy
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2011-12-06 21:21:11 +00:00
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NON_PROXIED_METHODS = Set[:object_id, :__send__, :__id__, :==, :equal?, :"!", :"!=", :instance_eval,
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:instance_variables, :instance_variable_get, :instance_variable_set,
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:remove_instance_variable]
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NON_PROXIED_INSTANCE_VARIABLES = Set[:@__receiver__, :@__fallback__]
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2011-12-06 20:05:31 +00:00
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instance_methods.each do |method|
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2011-12-06 21:21:11 +00:00
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unless NON_PROXIED_METHODS.include?(method.to_sym)
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2011-12-06 20:05:31 +00:00
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undef_method(method)
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end
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end
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def initialize(receiver, fallback)
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@__receiver__ = receiver
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@__fallback__ = fallback
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end
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def id
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@__receiver__.__send__(:id)
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end
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# Special case due to `Kernel#sub`'s existence
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def sub(*args, &block)
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__proxy_method__(:sub, *args, &block)
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end
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2011-12-06 21:21:11 +00:00
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# Special case to allow proxy instance variables
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def instance_variables
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2012-10-29 19:24:59 +00:00
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# Ruby 1.8.x returns string names, convert to symbols
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super.map(&:to_sym) - NON_PROXIED_INSTANCE_VARIABLES.to_a
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2011-12-06 21:21:11 +00:00
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end
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2011-12-06 20:05:31 +00:00
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def method_missing(method, *args, &block)
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__proxy_method__(method, *args, &block)
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end
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def __proxy_method__(method, *args, &block)
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begin
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@__receiver__.__send__(method.to_sym, *args, &block)
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rescue ::NoMethodError => e
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begin
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@__fallback__.__send__(method.to_sym, *args, &block)
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rescue ::NoMethodError
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raise(e)
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end
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end
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end
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end
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end
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