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marble StillMaintained Status Build Status

Marble is a Ruby object builder. It makes generating complex Ruby objects, and by extension JSON and YAML, much more readable. It's especially useful for Rails JSON API templates.


Marble works both with and without Rails. Installation is as simple as adding this line to your Gemfile:

gem 'marble'

If you'd like to use marble without bundler, you can also directly install the gem:

gem install marble


First, require marble and create a builder.

require 'marble'
builder =

This builder can build any Ruby object using the #build method. The yielded value is the current builder: do |m|
end # => ['foo']

However, this isn't very useful. The #array and #hash methods are far more interesting. They allow you to build complex arrays and hashes in a minimal amount of lines:

builder.array do |m|
  m.item 'foo'
end # => ['foo']

builder.hash do |m| 'bar'
end # => { 'foo' => 'bar' }

The returned value can be converted to JSON and YAML, giving you a really concise way of creating JSON and YAML templates for API's.

See the Marble documentation for more details.

Usage with Rails

Marble provides a template handler for Rails. It supports object literal, JSON, and YAML output formats. Name your view template with the extension marble. The template creates a builder with the name marble for you to use. You can rename it using the block parameter. For example, in order to generate a JSON view:

# view_name.json.marble
marble.hash do |m| 'bar'

# Renders: {"foo": "bar"}

See the Marble::RailsTemplateHandler documentation for more details.

Note on Patches/Pull Requests

  • Fork the project.
  • Make your feature addition or bug fix.
  • Add tests for it. This is important so I don't break it in a future version unintentionally.
  • Commit, but do not mess with the Rakefile. If you want to have your own version, that is fine but bump the version in a commit by itself in another branch so I can ignore it when I pull.
  • Send me a pull request. Bonus points for git flow feature branches.



Marble is licensed under the MIT License. See LICENSE for details.