Emotions is a Ruby library that allows ActiveRecord records to
express (and hopefully store) emotions about other records.

Add this line to your application’s Gemfile:

gem 'emotions'

And then execute:

$ bundle

Run the migration to add the emotions table and the Emotion model:

$ rails generate emotions:install

Configure the allowed emotions.

Emotions.configure do |config|
  config.emotions = [:happy, :sad]
end

Create a couple of models.

class Picture < ActiveRecord::Base
  acts_as_emotive
end

class User < ActiveRecord::Base
  acts_as_emotional
end

Express emotions towards other records.

user = User.find(1)
picture = Picture.find(2)

user.happy_about!(picture)
user.sad_about!(picture)
user.emotions_about(picture)
# => [:happy, :sad]

user.happy_about?(picture)
# => true

user.no_longer_sad_about!(picture)
user.sad_about?(picture)
# => false

User.happy_about(picture)
# => #<ActiveRecord::Relation [#<User id=1>]>

user.express!(:sad, picture)
user.sad_about?(picure)
# => true

Most of the times, you would want to get a quick look at about how many users expressed a certain emotion towards a certain picture. That could be an expensive operation.

However, if the emotive record has an <emotion>_emotions_count column, Emotions will populate its value with how many emotional records expressed that emotion towards it.

user.happy_about!(picture)

picture.happy_about.count
# SQL query that counts records and returns `1`

picture.happy_emotions_count
# Quick lookup into the column and returns `1`

Same thing for emotional records. If there’s a <emotion>_emotions_count column in the emotional model, Emotions will update it each time one of its records expresses that emotion towards another record.

user.happy_about!(picture)

user.happy_about.count
# SQL query that counts records and returns `1`

user.happy_emotions_count
# Quick lookup into the column and returns `1`

Emotions is © 2013-2015 Mirego and may be freely distributed under the New BSD license. See the LICENSE.md file.

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