👷‍🕳 HashDigger

A utilitarian lib to extract data from complex Hashes using String path with "recursions".

Installation

Add this line to your application's Gemfile:

gem 'hash_digger'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hash_digger

Usage

  _h  = {a: 1, b: 2}
  p HashDigger::Digger.dig(data: _h, path: '*') # => {:a=>1, :b=>2}
  p HashDigger::Digger.dig(data: _h, path: 'b') # => 2

  _a  = [1, 2, 3]
  p HashDigger::Digger.dig(data: _a, path: '*') # => [1, 2, 3]
  p HashDigger::Digger.dig(data: _a, path: '2') # => 3

  ah  = [{a: 42}, {a: 13, b: 7}]
  p HashDigger::Digger.dig(data: ah, path: '*.a') # => [42, 13]
  p HashDigger::Digger.dig(data: ah, path: '*.b', strict: false) # => [nil, 7]
  p HashDigger::Digger.dig(data: ah, path: '*.b', strict: false) { |result| result.compact } # => [7]

  ha  = {a: [1, 2, 3], b: [4, 5, 6]}
  p HashDigger::Digger.dig(data: ha, path: '*') # => {:a=>[1, 2, 3], :b=>[4, 5, 6]}
  p HashDigger::Digger.dig(data: ha, path: 'a.2') # => 3
  p HashDigger::Digger.dig(data: ha, path: 'b.0') # => 4

  aha = [{a: 42, b: 13}, [1, 2, 3]]
  p HashDigger::Digger.dig(data: aha, path: '*') # => [{:a=>42, :b=>13}, [1, 2, 3]]
  p HashDigger::Digger.dig(data: aha, path: '*.0', strict: false) # => [nil, 1]

  hah = {a: [1, 2, 3], b: {a: 13, b: 42}}
  p HashDigger::Digger.dig(data: hah, path: '*') # => {:a=>[1, 2, 3], :b=>{:a=>13, :b=>42}}
  p HashDigger::Digger.dig(data: hah, path: 'a') # => [1, 2, 3]
  p HashDigger::Digger.dig(data: hah, path: 'a.*') # => [1, 2, 3]
  p HashDigger::Digger.dig(data: hah, path: 'b.b') # => 42

  aah = [[{a: 1}, {b: 2}], [{a: 1}, {c: 3}]]
  p HashDigger::Digger.dig(data: aah, path: '*.*.a', strict: false) # => [1, nil, 1, nil]
  p HashDigger::Digger.dig(data: aah, path: '*.*.a', strict: false) { |result| result.compact } # => [1, 1]

  hhh = {a: {b: {c: {d: 'data'}}}}
  p HashDigger::Digger.dig(data: hhh, path: 'a.b.c.d') # => "data"

  # => Correct error being raised! YAY! HashDigger::DigError
  begin
    p HashDigger::Digger.dig(data: hhh, path: 'a.b.z.d')
  rescue HashDigger::DigError => e
    puts "Correct error being raised! YAY! #{e.class}"
  end

  hahah = {a: {b: 42 }, c: [{d: [{test: 'ok'}, {test: 'well'}]}]}
  p HashDigger::Digger.dig(data: hahah, path: 'c.*.d.*') # => [[{:test=>"ok"}, {:test=>"well"}]]
  p HashDigger::Digger.dig(data: hahah, path: 'c.*.d.*.*') # => [{:test=>"ok"}, {:test=>"well"}]

  hhhah = {a: {b: {c: {d: [{info: 42}, {info: 13}, {something: 'test'}]}}}}
  p HashDigger::Digger.dig(data: hhhah, path: 'a.b.c.d.*.info', strict: false) # => [42, 13, nil]
  p HashDigger::Digger.dig(data: hhhah, path: 'a.b.c.d.*.info', strict: false, default: '<ERROR>') # => [42, 13, "<ERROR>"]
  p HashDigger::Digger.dig(data: hhhah, path: 'a.b.c.d.*.something', strict: false) # [nil, nil, "test"]

  p (HashDigger::Digger.dig(data: hhhah, path: 'a.b.c.d.*.something', strict: false) do |result|
    result.map {|node| node.nil? ? 'OK' : node }
  end) # ["OK", "OK", "test"]

Existing solutions

There are many existing solutions out there implemented as snippets of code, libraries & answers on StackOverflow, here's just a short list of some:

• xkeys
• vine
• hashie
• Accessing elements of nested hashes in Ruby
• Ruby Style: How to check whether a nested hash element exists
• How to avoid NoMethodError for nil elements when accessing nested hashes?

Development

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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/smileart/hash_digger. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant 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 HashDigger project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.