Metable Concern for Rails ActiveRecord

metable.rb

module Metable
    extend ActiveSupport::Concern

    included do
        serialize :meta, JSON
    end

    def is_metable?
        has_attribute?(:meta)
    end

    def has_meta?(key)
        meta = dump_meta()
        meta.has_key?(key)
    end

    def get_meta(key, default=nil)
        meta = dump_meta()

        if has_meta?(key)
            meta[key]
        else
            default
        end
    end

    def put_meta!(key, value)
         meta = dump_meta()

         meta[key] = value
         write_attribute(:meta, meta)
         self.save!
    end

    def forget_meta!(key)
        meta = dump_meta()

        if has_meta?(key)
            meta.delete(key)
            write_attribute(:meta, meta)
            self.save!
        end
    end

    def dump_meta()
        read_attribute(:meta)
    end
end