Dynamic Resque job handlers

rescue_spec.rb

require "spx_utils/resque"

describe SpxUtils::Resque do
  describe ".job_handler" do

    subject do
      SpxUtils::Resque.job_handler(:my_queue) do |x, y|
        x + y
      end
    end

    specify { subject.class.name.to_s == "My_queue" }

    describe "<generated>.queue" do
      it { should respond_to(:queue) }
      its(:queue) { should == :my_queue }
    end

    describe "<generated>.perform" do
      specify { subject.perform(1, 2).should == 3 }
    end
  end
end

resque.rb

class Object
  def metaclass
    class << self
      self
    end
  end
end


module SpxUtils
  class Resque

=begin
    Generates a dynamic Resque job handler class with a block.
    Allows for ridiculously simple definition of job handlers.

    klass = SpxUtils::Rescue.job_handler :my_queue do |*args|
      p args
    end

    klass.queue
    klass.perform 1, 2, 3

    Resque.enqueue klass, 4, 5, 6
=end
    def self.job_handler(queue_name, &block)
      job_handler_class queue_name, &block
    end

    private

    def self.job_handler_class(queue_name, &block)
      class_name = queue_name.capitalize
      klass = Object.const_set(class_name, Class.new)
      klass.class_eval do
        def self.create_method(name, &block)
          metaclass.instance_eval do
            define_method(name) do |*args|
              begin
                block.call(*args)
              rescue Exception => e
                puts "\n\nException: #{e.inspect}"
                puts "\nBacktrace: #{e.backtrace}"
              end
            end
          end
        end

        create_method :queue do
          queue_name
        end
        create_method :perform, &block
      end
      klass
    end
  end
end