Comma

A library for generating comma-separated values (CSV) from Ruby objects, arrays, and supported ORM collections.

You need Ruby 3.0 or later.

For Rails / ActiveRecord integration, this repository is currently tested against ActiveRecord and Rails 6.0 through 7.1 on Ruby 3.0 through 3.4.

Comma is distributed as a gem, best installed via Bundler.

Include the gem in your Gemfile:

gem 'comma', '~> 4.9.0'

Or, if you want to live life on the edge, you can get master from the main comma repository:

gem 'comma', git: 'https://github.com/comma-csv/comma.git'

Then, run bundle install.

Define a CSV format on your object with comma. Calling to_comma on a single object returns the row values, while calling it on an array or supported collection generates CSV output:

class User
  attr_reader :first_name, :last_name

  def initialize(first_name, last_name)
    @first_name = first_name
    @last_name = last_name
  end

  comma do
    first_name
    last_name
    full_name 'Name'
  end

  def full_name
    "#{first_name} #{last_name}".strip
  end
end

user = User.new('Ada', 'Lovelace')
user.to_comma
# => ["Ada", "Lovelace", "Ada Lovelace"]

users = [User.new('Ada', 'Lovelace'), User.new('Grace', 'Hopper')]
users.to_comma
# => "First name,Last name,Name\nAda,Lovelace,Ada Lovelace\nGrace,Hopper,Grace Hopper\n"

You can also define named styles and select them when generating CSV:

class User
  comma :short do
    first_name
    last_name
  end
end

users.to_comma(:short)

In Rails controllers, requiring the gem registers render csv: support:

def index
  render csv: User.all
end

See the wiki for more usage examples.

Install dependencies:

bundle install
bundle exec appraisal install

Run the default test suite and linter:

bundle exec rspec spec
bundle exec rubocop -P

Run a single example:

bundle exec rspec spec/comma/comma_spec.rb:205

To run the test suite across the Rails / ActiveRecord gemfile matrix, this repository uses Appraisal:

bundle exec appraisal rake spec

You can also run a specific spec under one appraisal:

bundle exec appraisal rails7.1.3 bundle exec rspec spec/controllers/users_controller_spec.rb

Please make sure bundle exec rspec spec, bundle exec rubocop -P, and any relevant bundle exec appraisal ... commands pass before opening a pull request.

We use SemVer for versioning. For the versions available, see the tags on this repository.

• Marcus Crafter - Initial work
• Tom Meier - Initial work
• Eito Katagiri

This project is licensed under the MIT License - see the MIT-LICENSE file for details.