Flattenator

Converts a deeply nested hash with a flattened hash, prefixing the keys for child hashes. It's easier to show than to explain:

# start with this
{
  foo: "bar",
  baz: {
    apple: 2,
    banana: 5,
    carrot: 0,
  },
}
# end with this
{
  "foo" => "bar",
  "baz_apple" => 2,
  "baz_banana" => 5,
  "baz_carrot" => 0,
}

Add this line to your application's Gemfile:

gem 'flattenator'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install flattenator

Flattenator::Hash.new(hash).flattened

By default, a JSON-encoded version of the object being flattened will be included in the flattened hash, but this can be turned off.

original = {
  foo: "bar",
  options: {
    jiggle_handle: true,
    tighten_valve: false,
  },
}

Flattenator::Hash.new(original).flattened
{
  "foo" => "bar",
  "options" => "{\"jiggle_handle\":true,\"tighten_valve\":false}"
  "options_jiggle_handle" => true,
  "options_tighten_valve" => false,
}

Flattenator::Hash.new(original, include_unflattened: false).flattened
{
  "foo" => "bar",
  "options_jiggle_handle" => true,
  "options_tighten_valve" => false,
}

Additionally, arrays are flattened into the form {key}_{index}, like so:

original = {
  fruits: [
    "apple",
    "banana",
    "citrus",
  ],
  vegetables: [
    "daikon",
    "eggplant",
  ],
}

Flattenator::Hash.new(original).flattened
{
  "fruits" => "[\"apple\",\"banana\",\"citrus\"]",
  "fruits_0" => "apple",
  "fruits_1" => "banana",
  "fruits_2" => "citrus",
  "vegetables" => "[\"daikon\",\"eggplant\"]",
  "vegetables_0" => "daikon",
  "vegetables_1" => "eggplant",
}

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/pbyrne/flattenator. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Flattenator project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.