Module: PermaCache::ClassMethods

Defined in:
lib/perma_cache.rb

Instance Method Summary collapse

Instance Method Details

#perma_cache(method_name, options = {}) ⇒ Object



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# File 'lib/perma_cache.rb', line 44

def perma_cache(method_name, options = {})
  class_eval do

    was_rebuilt_inst_var = "@#{method_name}_was_rebuilt"

    define_method "#{method_name}_base_key" do
      key = []
      key << "perma_cache"
      key << "v#{PermaCache.version}"

      key << PermaCache.build_key_from_object(self)

      if options[:obj]
        key << PermaCache.build_key_from_object(send(options[:obj]))
      end

      if options[:version]
        key << "v#{options[:version]}"
      end

      key
    end

    define_method "#{method_name}_perma_cache_key" do
      [
        send("#{method_name}_base_key"),
        (send("#{method_name}_key") rescue nil),
        method_name
      ].flatten.compact.map(&:to_s).reject{|k| k.empty?}.join('/').gsub(' ','_')
    end

    define_method "#{method_name}!" do
      instance_variable_set(was_rebuilt_inst_var , true)
      send("#{method_name}_without_perma_cache").tap do |result|
        PermaCache.cache.write(send("#{method_name}_perma_cache_key"), result, :expires_in => options[:expires_in])
      end
    end

    define_method "#{method_name}_get_perma_cache" do
      PermaCache.cache.read(send("#{method_name}_perma_cache_key"))
    end

    define_method "#{method_name}_with_perma_cache" do
      instance_variable_set(was_rebuilt_inst_var , false)

      send("#{method_name}_get_perma_cache") ||
      (
        instance_variable_set(was_rebuilt_inst_var , true) &&
        send("#{method_name}!")
      )
    end

    define_method "#{method_name}_was_rebuilt?" do
      instance_variable_get(was_rebuilt_inst_var ) == true
    end

    alias_method_chain method_name, :perma_cache
  end
end