build codecov Gem Version Conventional Commits


Install the gem and add to the application's Gemfile by executing:

$ bundle add acts_as_reactable

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install acts_as_reactable


1. create the Reaction model

# rails g migration create_reactions

# with default id type
create_table :reactions do |t|
  t.references :reactable, polymorphic: true, null: false
  t.references :reactor, polymorphic: true, null: false
  t.string :emoji, null: false, index: true

  t.index [:reactable_type, :reactable_id, :reactor_type, :reactor_id, :emoji], unique: true, name: 'index_reactions_on_reactable_and_reactor_and_emoji'

# with uuid id
create_table :reactions, id: :uuid do |t|
  t.references :reactable, polymorphic: true, type: :uuid, null: false
  t.references :reactor, polymorphic: true, type: :uuid, null: false

2. annotate reactable and reactor models

# reactable
class Post < ApplicationRecord

# reactor
class User < ApplicationRecord


adding/updating reactions

post.add_reactions(user, "😀")
post.add_reactions(user, ["😞", "🙃"])

removing reactions

post.remove_reactions(user, "😀")
post.remove_reactions(user, ["😞", "🙃"])

private opinion on reactable from reactor

reactions = ActsAsReactable::Reaction.where(reactable: post, reactor: user)

group, count and sort to get a summary of public opinion

ActsAsReactable::Reaction.where(reactable: reactor).group(:emoji).order('count_id DESC').count(:id)

# { "😀": 10, "😢": 5, "😣": 1 }


Why saving "😂" instead of "face_with_tears_of_joy"

  • Technically, there's no concrete name/key/id for emoji (and modifiers like skin tone). The CLDR short names "vary by language" and "may change", besides, are those names case sensitive? Should we use -, _ or as divider? How to append tone variant? There are several error prone decisions to make.
  • It's easier to store since all modern database supports encodings (e.g. UTF-8) for unicode characters.
  • It's easy to validate with libs/regex (e.g. unicode-emoji).
  • It takes less size on disk to store (and presumably less time to index/sort/match) one unicode character 😂 (4 bytes) than face with tears of joy (22 bytes). This is a great article to explain how utf-8 works


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


Bug reports and pull requests are welcome on GitHub at 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.

Code of Conduct

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