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Last Update: | Sat Feb 12 20:53:28 +0000 2011 |
h1. rubigen
h1. Ruby Generator Framework
h2. What
A framework to allow Ruby applications to generate file/folder stubs (like the rails command does for Ruby on Rails, and the ‘script/generate’ command within a Rails application during development).
The RubyConf 2007 presentation is now "online":rubyconf2007.confreaks.com/d3t1p1_rubigen.html together with the theme from the A-Team.
h2. Background
RubiGen is originally extracted from Ruby on Rails (specifically the rails_generator from its railties gem).
The rails_generator was hardcoded with Rails-specific dependencies (RAILS_ROOT), Rails generators (‘app’ = Rails application; ‘model’ = Rails model+tests+migration), and generally assumed it was the only generator framework within the Ruby world (it was). So, any RubyGem whose name ended with ‘_generator’ was assumed to be a generator for a Rails application.
But if you are developing an Adhearsion application, then you may want a different set of generators. If you are developing a RubyGem, then you will want a different set of generators.
RubiGen exists to give different development environments their own generator framework.
h2. Installing
RubiGen is only required at development time, and normally isn‘t required at deployment time (unless your application uses it to generate files etc for its users).
On your development machine:
<pre syntax="ruby">sudo gem install rubigen</pre>
h2. Usage
RubiGen will be normally integrated into another RubyGem, such as newgem or rails or camping, rather than be used on its own.
These frameworks might use RubiGen for two reasons:
# To generate an initial stub for developers, e.g. rails generated a stub to write a Rails application. newgem generates a stub to write a RubyGem. <br/>
BTW - RubiGen has a builtin application <code>ruby_app</code> which generates a bare-bones Ruby application stub (lib, test, and script folders, plus a Rakefile, and a script/generate script)
# To generate components within their development areas, e.g. Rails had its script/generate script within each Rails application, which hooked back into the rails_generator to lookup and execute generators.
So, there are two steps to integrating RubiGen into your framework:
# Use it to generate an initial stub for the developers of your framework. This would create the folders
(<code>lib/app</code>, <code>test</code>, <code>script</code>, <code>doc</code>, <code>log</code>, etc) and starting files (<code>Rakefile</code>, <code>README.txt</code>, <code>test/test_helper.rb</code> etc). Importantly, it would generate a <code>script/generate</code> file. The <code>script/generate</code> file (example below) will allow developers of your framework to generate components/extensions within the framework. <br /> RubiGen allows you to restrict which generators are available. For example, within RubyGem development environment (as generated by <code>newgem</code>), the <code>script/generator</code> only shows <code>rubygem</code>-related generators. Rails could restrict <code>script/generator</code> to only show Rails related generators
# Your framework RubyGem (e.g. newgem or rails RubyGems) needs to add rubigen as a
dependency, so that users of your RubyGem can access the generator framework.
h1. Creating generators
There are two types of generators:
# Application Generators - used by developers of your framework to get started.
Generally, you will create one Application Generator for your framework. It generates a base stub (such as the <code>rails</code> stub for new Rails applications) for your framework users.
# Component Generators - used by developers to extend their application.
You may include 1+ built-in generators with your framework. Developers can also write generators for your framework, and like Rails' generator install them in various places and have access to their via RubiGen.
h2. Creating an Application Generator for your Framework
h3. Easy way
"newgem":newgem.rubyforge.org/ (v0.13.0+) can generate an Application Generator for a RubyGem.
# Create new RubyGem: newgem foobar # Create generator: script/generator application_generator foobar # Update tests + generator # Install # Run with: foobar
For more documentation, run script/generator application_generator
h3. DIY
Without RubiGen, to give your users a head start and create a stub for them, you will copiously use mkdir_p and File.open. Your script will either be primitive (only create the bare folders and very few files) or it will be very long and unreadable (ok, perhaps I‘m just talking about the newgem script, which I am dubiously responsible for… :P).
With RubiGen, you can create stubs using powerful, yet simple, syntax. Templates are extracted into a templates folder, and activating the generator from a script requires only a few lines of code.
These are the newgem files related to its Application Generator.
bin/ bin/newgem # Appliction Generator script; Usage: newgem gemname [options] app_generators/ app_generators/newgem/ app_generators/newgem/newgem_generator.rb app_generators/newgem/USAGE app_generators/newgem/templates/ app_generators/newgem/templates/app.rb app_generators/newgem/templates/History.txt app_generators/newgem/templates/... lots and lots of templates
The bin/newgem script is very simple, and looks like:
<pre syntax="ruby"> require ‘rubygems’ require ‘rubigen‘
if %w(-v —version).include? ARGV.first
require 'newgem/version' puts "#{File.basename($0)} #{Newgem::VERSION}" exit(0)
end
require ‘rubigen/scripts/generate’ RubiGen::Base.use_application_sources! RubiGen::Scripts::Generate.new.run(ARGV, :generator => ‘newgem’) </pre>
You can copy and paste this for your own generator script, and place it in your RubyGem‘s bin folder. Change newgem to your RubyGem‘s name in the script above (and in all the folders listed above too)
NOTE: If you leave newgem there, then it will execute the newgem_generator.rb generator; as the generators are loaded from all RubyGem‘s having /app_generators folders.
So, for your RubyGem, you need to keep the /app_generators folder (as you are creating an Application Generator, not a Component Generator), but change newgem to your gem name in all the subfolders and files. ESPECIALLY newgem_generator.rb -> yourgem_generator.rb, as this is how the generator is discovered (via RubiGen::Base.use_application_sources!).
All the generator work is performed within yourgem_generator.rb. A stub for it will be:
<pre syntax="ruby"> require ‘rbconfig‘
class YourgemGenerator < RubiGen::Base
DEFAULT_SHEBANG = File.join(Config::CONFIG['bindir'], Config::CONFIG['ruby_install_name']) default_options :shebang => DEFAULT_SHEBANG, :an_option => 'some_default' attr_reader :app_name, :module_name def initialize(runtime_args, runtime_options = {}) super usage if args.empty? @destination_root = args.shift @app_name = File.basename(File.expand_path(@destination_root)) @module_name = app_name.camelize extract_options end def manifest # Use /usr/bin/env if no special shebang was specified script_options = { :chmod => 0755, :shebang => options[:shebang] == DEFAULT_SHEBANG ? nil : options[:shebang] } windows = (RUBY_PLATFORM =~ /dos|win32|cygwin/i) || (RUBY_PLATFORM =~ /(:?mswin|mingw)/) record do |m| # Root directory and all subdirectories. m.directory '' BASEDIRS.each { |path| m.directory path } # Root m.template_copy_each %w( Rakefile ) m.file_copy_each %w( README.txt ) # Test helper m.template "test_helper.rb", "test/test_helper.rb" # Scripts %w( generate ).each do |file| m.template "script/#{file}", "script/#{file}", script_options m.template "script/win_script.cmd", "script/#{file}.cmd", :assigns => { :filename => file } if windows end end end protected def banner <<-EOS
Create a stub for #{File.basename $0} to get started.
Usage: #{File.basename $0} /path/to/your/app [options]" EOS
end def add_options!(opts) opts.separator '' opts.separator "#{File.basename $0} options:" opts.on("-v", "--version", "Show the #{File.basename($0)} version number and quit.") end # Installation skeleton. Intermediate directories are automatically # created so don't sweat their absence here. BASEDIRS = %w( doc lib log script test tmp )
end </pre>
Easy peasy.
h2. Creating a Component Generator for your Framework
You can include Component Generators in RubyGems, and they will be automatially picked up by your framework‘s script/generate script.
h3. Easy way
Use "newgem":newgem.rubyforge.org/, (v0.13.0+), and run:
<pre> script/generate component_generator </pre>
and follow the instructions.
h2. Live at RubyConf 2007
RubiGen had the 9am, Sunday timeslot at RubyConf 2007 and was "recorded for your viewing pleasure":rubyconf2007.confreaks.com/d3t1p1_rubigen.html.
h2. Forum
"groups.google.com/group/rubigen":http://groups.google.com/group/rubigen
h2. How to submit patches
Read the "8 steps for fixing other people‘s code":drnicwilliams.com/2007/06/01/8-steps-for-fixing-other-peoples-code/ and for section "8b: Submit patch to Google Groups":drnicwilliams.com/2007/06/01/8-steps-for-fixing-other-peoples-code/#8b-google-groups, use the Google Group above.
The source for this project is available via git. You can "browse and/or fork the source":github.com/drnic/rubigen/tree/master, or to clone the project locally:
<pre>git clone git://github.com/drnic/rubigen.git</pre>
The original Subversion repository is svn://rubyforge.org/var/svn/rubigen/trunk for anonymous access.
h2. Thanks go to…
"Jeremy Kemper":bitsweat.net/ (bitsweat) who wrote the original "Rails Generator":dev.rubyonrails.org.
h2. License
This code is free to use under the terms of the MIT license.
h2. Contact
Comments are welcome. Send an email to "Dr Nic Williams":drnicwilliams@gmail.com via the "forum":groups.google.com/group/rubigen