Job.rb

#This is a really crappy way to do job runners.
#But I'd never used a job queue before, so I 
#wanted to do it at least once the wrong way
#to figure it out.

require 'colored'

class Job
  include DataMapper::Resource
  
  property :id, Serial
  property :name, String
  property :params, Object
  property :failed, Boolean
  
  class NilJobFailure < StandardError; end
  
  def self.next_job
    j = first :failed => nil
    j.failed = true
    j.save
    j
  end
  
  def self.pull_job
    job = next_job
    transaction do
      raise NilJobFailure.new if job.nil?
      begin
        puts "~ Precessing #{job.id} #{job} #{job.name} #{job.params}".bold
        send job.name, *job.params
        job.destroy
      rescue => e
        puts e.message.red.bold
        job.failed = true
        job.save
        rollback
      end
    end
    pull_job
  end
  
  def self.rescue_failed_jobs
    all(:failed => true).each do |failed|
      failed.update_attributes :failed => nil
    end
  end
end