MadFlatter

mad_flatter is a Ruby gem that takes a Ruby Hash and flattens the Hash keys to create a new Hash with unique Hash keys; that is, embedded Hashes use their respective keys as namespaces to create unique keys across the entire Hash. For example:

user0 = {
  name: 'john',
  wife: { name: 'mary' },
  children: {
    child0: 'sam',
    child1: 'martha'
  }
}

result0 = MadFlatter::Service.new.execute(hash: user0)
#=>
{
  :name=>"john",
  :wife_name=>"mary",
  :children_child0=>"sam",
  :children_child1=>"martha"
}

The :namespace option may be used to append to all Hash keys, to ensure that all Hash keys are unique across multiple Hashes with the same structure. For example:

# Continuing from the above example...
user1 = {
  name: 'james',
  wife: { name: 'molly' },
  children: {
    child0: 'steve',
    child1: 'maybell'
  }
}

options = { namespace: :ns1 }
result1 = MadFlatter::Service.new.execute(hash: user1, options: options)
#=>
{
  :ns1_name=>"james",
  :ns1_wife_name=>"molly",
  :ns1_children_child0=>"steve",
  :ns1_children_child1=>"maybell"
}

result0.merge(result1)
#=>
{
  :name=>"john",
  :wife_name=>"mary",
  :children_child0=>"sam",
  :children_child1=>"martha",
  :ns1_name=>"james",
  :ns1_wife_name=>"molly",
  :ns1_children_child0=>"steve",
  :ns1_children_child1=>"maybell"
}

The metadata can optionally be returned by setting the :metadata option to true. This option is false by default. For example:

best_cake = {
  name: 'black forest',
  options: {
    cherries: false
  }
}

options = { namespace: :best_cake, metadata: true }
result = MadFlatter::Service.new(options: options).execute(hash: best_cake)
#=>
{
  :best_cake_name=>
    {
      :value=>"black forest",
      :metadata=> {
        :key=>:name,
        :dig=>[]
      }
    },
  :best_cake_options_cherries=> {
    :value=>false,
    :metadata=> {
      :key=>:cherries,
      :dig=>[:options]
    }
  }
}

result.each_pair do |key, value|
  original_key = value[:metadata][:key]
  original_value = best_cake.dig(*value[:metadata][:dig], original_key)
  puts 'Original Hash key/value:'
  puts "\t#{original_key} => \"#{original_value}\""
  puts 'New Hash key/value:'
  puts "\t#{key} => \"#{value[:value]}\""
  puts
end

Prints:

Original Hash key/value:
	name => "black forest"
New Hash key/value:
	best_cake_name => "black forest"

Original Hash key/value:
	cherries => "false"
New Hash key/value:
	best_cake_options_cherries => "false"

Installation

Add this line to your application's Gemfile:

gem 'mad_flatter'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install mad_flatter

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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 the created tag, and push the .gem file to rubygems.org.

Contributing

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

License

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

Code of Conduct

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