https://github.com/tarcieri/resque-workflow

A DSL for describing workflows whose steps are Resque jobs
https://github.com/tarcieri/resque-workflow

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A DSL for describing workflows whose steps are Resque jobs

• Host: GitHub
• URL: https://github.com/tarcieri/resque-workflow
• Owner: tarcieri
• License: mit
• Created: 2010-10-22T02:01:05.000Z (about 14 years ago)
• Default Branch: master
• Last Pushed: 2011-01-25T03:52:29.000Z (almost 14 years ago)
• Last Synced: 2024-05-01T23:13:27.029Z (7 months ago)
• Language: Ruby
• Homepage:
• Size: 94.7 KB
• Stars: 13
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.markdown
  • License: LICENSE

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README

        
Resque::Workflow

=======

A DSL for describing worflows whose steps are Resque jobs

Philosophy

----------

Workflows are finite state machines, described as a set of states whose

transitions are jobs.  Jobs can either succeed or fail, and workflows

must account for either case when transitioning between states.

Job failures fall into one of three categories:

* Temporary failure: Something went wrong which might magically fix itself at

  some point in the future.  The job should be retried a certain number of

  times until it succeeds, or until it's failed so much we just give up.

  

* Error: An exception occurred in the system.  The problem should be remedied

  and the job retried once it's been fixed.

  

* Permanent failure: The job is completely hosed and there's no way to fix it.

Workflows, as part of their design, will automatically retry jobs unless they

permanently fail.  This means that all jobs must be *idempotent*: if they are

run multiple times by mistake, they will not cause adverse effects on the

system such as unexpected duplicated objects.  Instead, if the job is run

multiple times the system should always end in a clean, expected state.

Foreman cannot ensure your jobs are idempotent.  Ensuring they are is left as

an exercise to the user.

Example Workflow

----------------

    class Cat < ActiveRecord::Base

      include Resque::Workflow

  

      states :new, :caught, :in_bathroom, :washed, :default => :new 

      workflow do

        # Catch the cat

        job_for :new, :success => :caught do |cat|

          puts "Catching the cat..."

          cat.grab      

        end

  

        # Walk to bathroom

        job_for :caught, :success => :in_bathroom, :fail => :new do |cat|

          puts "Carrying cat to the bathroom"

          cat.carry_to_bathroom

        end

    

        # Wash cat

        job_for :in_bathroom, :success => :washed do |cat|

          puts "Washing cat"

          cat.wash

        end

      end

  

      def grab  

        puts "Cat caught!"

      end

  

      def carry_to_bathroom

        puts "Cat carried to bathroom!"

      end

  

      def wash

        puts "Cat washed!"

      end

    end

Status

------

A basic example of the DSL I have in mind is available in spec/base_spec.rb.

However, this DSL is very much unimplemented at this point.

Copyright

---------

Copyright (c) 2010 Tony Arcieri. See LICENSE for details.