ActsAsFollowable - Model following

This plugin is a Rails3 alternative of the plugin called acts_as_follower by tcocca. It allows any model to follow other models and a model can be followed by other models.

Usually you will use this plugin when implementing a blog-style website where users will follow other users or for users to follow Books, etc…

Installation (Rails 3 ready)

Add this line to your Gemfile (and run bundle install):

gem 'acts_as_followable'

Run the generator which will generate a migration file.

rails g acts_as_followable
rake db:migrate

The plugin comes with a Follow model file. You can extend the default model by creating the app/models/follow.rb file with content.

class Follow
  ... your extension here ...
end

Setup

If you would like a model to follow or to be followed by any other model, just add the mixin:

class User < ActiveRecord::Base
  ...
  acts_as_followable
  ...
end

Examples

To have an object start following another use the following: 

book = Book.find(1)
user = User.find(1)
user.follow(book)

To stop following an object use the following:

user.stop_following(book)

You can remove all the followers/followings like this:

user.destroy_followers_by_type('User')
user.destroy_followings_by_type('Book')

You can check to see if an object is following another object through the following:

user.following?(book)

You can check to see if an object is followed by another object through the following:

book.followed_by?(user)

To get a list of followers by a given type use the following (e.g. list of users that follow a book):

User.following(book)
or
book.followers_by_type('User')
or
book.user_followers

# Also

User.following(book).order('name').limit(2)
or
book.followers_by_type('User').limit(2)
or
book.user_followers.order('name')

To get a list of records of a particular type which this record is following (e.g. list of books followed by a user)

Book.followed_by(user)
or
user.following_by_type('Book')
or
user.following_book

# Also

Book.followed_by(user).order('title').limit(2)
or
user.following_by_type('Book').limit(2)
or
user.following_book('title')

You can also query Follow model records like this:

# What user is following
user.follows
user.follows.limit(1)

# Who follows a book
book.followings
book.followings.order('created_at')

# Follow records by follower type
Follow.for_follower_type('User')
Follow.for_follower_type('User').limit(1)

# Follow records by followable type
Follow.for_followable_type('Book')
Follow.for_followable_type('Book').order('created_at')

# Follow records from follower
Follow.for_follower(user)
Follow.for_follower(user).limit(1)

# Follow records from followable
Follow.for_followable(book)
Follow.for_followable(book).order('created_at')

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