= {Tap (Task Application)}[http://tap.rubyforge.org]

tap n. to draw a supply from a resource

A configurable, distributable workflow framework.

== Description

Tap allows the construction of workflows that may be defined, configured, and run from the command line. The tasks and joins composing a workflow are easy to test, subclass, and distribute as gems.

Tap provides a standard library of {tasks}[http://tap.rubyforge.org/tap-tasks/index.html], {generators}[http://tap.rubyforge.org/tap-gen/index.html], and {test modules}[http://tap.rubyforge.org/tap-test/index.html] to expedite development.

• Website[http://tap.rubyforge.org]
• Github[http://github.com/bahuvrihi/tap/tree/master]
• {Google Group}[http://groups.google.com/group/ruby-on-tap]

== Usage

Tasks are defined as subclasses of Tap::Task.

[lib/goodnight.rb] require 'tap/task'

::task your basic goodnight moon task

Says goodnight with a configurable message.

class Goodnight < Tap::Task config :message, 'goodnight' # a goodnight message

def process(name)
  "#{message} #{name}"
end

end

Tap discovers tasks.

% tap list task: dump # dump data goodnight # your basic goodnight moon task list # list resources load # load data prompt # open a prompt signal # signal via a task join: gate # collects results join # unsyncrhonized multi-way join sync # synchronized multi-way join middleware: debugger # default debugger

Generates command-line documentation.

% tap goodnight --help Goodnight -- your basic goodnight moon task

Says goodnight with a configurable message.

usage: tap goodnight NAME

configurations: --message MESSAGE a goodnight message

options: --help Print this help --config FILE Specifies a config file

And provides a robust {syntax}[http://tap.rubyforge.org/rdoc/files/doc/Workflow%20Syntax.html] for building both simple and complex workflows. This joins a goodnight task to a dump task in order to print the goodnight message.

% tap goodnight moon -: dump goodnight moon

% tap goodnight world --message hello -: dump hello world

Workflows support the use of middleware to wrap the execution of each task, most commonly for logging and/or debugging.

% tap goodnight moon -: dump --/use debugger 21:06:53 0 << ["moon"] (Goodnight) 21:06:53 0 >> "goodnight moon" (Goodnight) 21:06:53 1 << "goodnight moon" (Tap::Tasks::Dump) goodnight moon 21:06:53 1 >> "goodnight moon" (Tap::Tasks::Dump)

Tap provides a set of {test modules}[http://tap.rubyforge.org/tap-test/index.html] to simplify testing of workflows both off and on the command-line (this documentation is tested, for example):

require 'tap/test/unit'

class ShellTestTest < Test::Unit::TestCase acts_as_shell_test

def test_goodnight_moon
  sh_test %q{
  % tap load 'goodnight moon' -: dump
  goodnight moon
  }
end

end

Tasks can be packaged into gems like any other code. Tap automatically finds tasks in gems containing a tap.yml file so that distribution feels normal and unobtrusive.

% tap load/yaml unresolvable constant: "load/yaml"

% gem install tap-tasks ...

% tap load/yaml "[1, 2, 3]" -: dump/yaml

• 1
• 2
• 3

For local tasks that don't need to be distributed, Tap provides declarations a-la {Rake}[http://rake.rubyforge.org/]. By default any tasks in a tapfile are available for use.

[tapfile] desc "concat file contents" task :cat do |config, *files| files.collect {|file| File.read(file) }.join end

desc "grep lines" task :grep, :e => '.' do |config, str| str.split("\n").grep(/#{config.e}/) end

% tap cat tapfile -:a grep -e task -:i dump task :cat do |config, *files| task :grep, :e => '.' do |config, str|

See the documentation for a greater explanation of the {workflow syntax}[http://tap.rubyforge.org/rdoc/files/doc/Workflow%20Syntax.html], several common {patterns}[http://tap.rubyforge.org/rdoc/files/doc/Examples.html], and the underlying {APIs}[http://tap.rubyforge.org/rdoc/files/doc/API.html].

== Installation

Tap is available as a gem on Gemcutter[http://gemcutter.org/gems/tap].

% gem install tap

== Info

Developer:: {Simon Chiang}[http://bahuvrihi.wordpress.com] License:: {MIT-Style}[http://tap.rubyforge.org/rdoc/files/MIT-LICENSE.html]