50 lines
1.5 KiB
Ruby
50 lines
1.5 KiB
Ruby
require 'hamster'
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require 'middleman-core/contracts'
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# Immutable Callback Management, complete with Contracts validation.
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module Middleman
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class CallbackManager
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include Contracts
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Contract Any
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def initialize
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@callbacks = ::Hamster.hash
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end
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Contract RespondTo[:define_singleton_method], ArrayOf[Symbol], Maybe[Proc] => Any
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def install_methods!(install_target, names, &block)
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manager = self
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names.each do |name|
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method_name = block_given? ? block.call(name) : name
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install_target.define_singleton_method(method_name) do |*keys, &b|
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key_set = keys.unshift(name)
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manager.add(key_set.length > 1 ? key_set : key_set.first, &b)
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end
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end
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install_target.define_singleton_method(:execute_callbacks) do |keys, *args|
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manager.execute(keys, args, self)
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end
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end
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Contract Or[Symbol, ArrayOf[Symbol]], Proc => Any
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def add(keys, &block)
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immutable_keys = keys.is_a?(Symbol) ? keys : ::Hamster::Vector.new(keys)
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@callbacks = @callbacks.put(immutable_keys) do |v|
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v.nil? ? ::Hamster.set(block) : v.add(block)
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end
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end
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Contract Or[Symbol, ArrayOf[Symbol]], Maybe[ArrayOf[Any]], Maybe[RespondTo[:instance_exec]] => Any
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def execute(keys, args=[], scope=self)
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immutable_keys = keys.is_a?(Symbol) ? keys : ::Hamster::Vector.new(keys)
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callbacks = @callbacks.get(immutable_keys)
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callbacks && callbacks.each { |b| scope.instance_exec(*args, &b) }
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end
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end
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end
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