Contents

= Pipeline

== Description

Pipeline is a Rails plugin/gem to run asynchronous processes in a configurable pipeline.

== Features

* Execution of sequential user-defined stages in an asynchronous pipeline
* Persistence of pipeline instances and stages
* Error recovery strategies:
  * Irrecoverable errors fail the entire pipeline
  * Recoverable errors are automatically retried (using dj's exponential retry strategy)
  * Recoverable errors that require user input pause the pipeline for further retry
* Cancelling of a paused pipeline

== Installation

Add the following lines to your config/environment.rb file:

  config.gem "pipeline", :version => ">= 0.0.2"

Run the following:

  rake gems:install
  rake gems:unpack # Optional, if you want to vendor the gem
  script/generate pipeline # To generate the migration scripts that will store pipelines
  rake db:migrate

You will also need to run your Delayed Job workers that will process the pipeline jobs in the background:

  rake jobs:work

== Dependencies

* Rails
* Delayed job (http://github.com/collectiveidea/delayed_job/tree/master)

== Usage

Check <tt>examples</tt> for more examples (including error-recovery and cancelling)

  class Step1 < Pipeline::Stage::Base
    def perform
      puts("Started step 1")
      sleep 2
      puts("Finished step 1")
    end
  end

  class Step2 < Pipeline::Stage::Base
    def perform
      puts("Started step 2")
      sleep 3
      puts("Finished step 2")
    end
  end
  
  class TwoStepPipeline < Pipeline::Base
    define_stages Step1 >> Step2
  end

  Pipeline.start(TwoStepPipeline.new)

== Copyright

Copyright (c) 2009 Danilo Sato. See LICENSE for details.

Version data entries

2 entries across 2 versions & 2 rubygems

Version	Path
dtsato-pipeline-0.0.2	README.rdoc
pipeline-0.0.2	README.rdoc