HasFriendship

Add friendship features to your ActiveRecord models.

HasFriendship allows ActiveRecord objects to send, accept, and decline friend requests using self-refernetial polymorphic association.

Getting started

Add HasFriendship to your Gemfile:

gem 'has_friendship'

After you bundle HasFriendship, you need to copy migrations and migrate:

$ rails has_friendship_engine:install:migrations
$ rake db:migrate

Gem upgrades

After gem updates, it may be necessary to run subsequent migrations.

$ rails has_friendship_engine:install:migrations

Will install new migrations if they're necessary.

Usage

Simply drop in has_friendship to a model:

class User < ActiveRecord::Base
  has_friendship
end

Managing friendship

Now, instances of User can send, accept, and decline friend requests:

@mac = User.create(name: "Mac")
@dee = User.create(name: "Dee")

# @mac sends a friend request to @dee
@mac.friend_request(@dee)

# @dee can accept the friend request
@dee.accept_request(@mac)

# @dee can also decline the friend request
@dee.decline_request(@mac)

A friendship can also be removed:

# @dee removes @mac from its friends
@dee.remove_friend(@mac)

Blocking a friendable

A friendable can be blocked. When blocked, the friendable cannot request or remove friendship to the one that initially blocked it.

@dee.request_friend(@mac)

# @mac blocks @dee from making any more friendship actions
@mac.block_friend(@dee)

# @mac unblocks @dee
# Only @mac can perform this action
@mac.unblock_friend(@dee)

Checking friendship

# Check if there is an accepted friendship between @mac and @dee
@mac.friends_with?(@dee)

Type of friends

There are four types of friends:

• requested_friends
• pending_friends
• blocked_friends
• friends

Each type returns an array of friends, which should be looped through to access specific friends. They can be accessed using association.

requested_friends

Instances that sent friend request that has not been accepted.

@mac.friend_request(@dee)

@dee.requested_friends # => [@mac]

pending_friends

Instances that received but has not accepted the friend request.

@mac.friend_request(@dee)

@mac.pending_friends # => [@dee]

blocked_friends

Instances that are blocked from taking any friendship actions

@dee.friend_request(@mac)
@mac.block_friend(@dee)

@mac.blocked_friends # => [@dee]

friends

Instances with accepted Friendship.

@mac.friend_request(@dee)
@dee.accept_request(@mac)

@mac.friends # => [@dee]
@dee.friends # => [@mac]

Custom validations

You can provide custom validations for the friendship by implementing friendship_errors method on your Friendable model.

Returning an array with any elements will result in the friendship not being established.

def friendship_errors(wannabe_friend)
  return if can_become_friends_with?(wannabe_friend)

  [
    "Cannot become friends with #{wannabe_friend.email}",
  ]
end

Callbacks

To use callbacks you can add methods described below to your Friendable model.

def on_friendship_created(friendship)
  ...
end

def on_friendship_accepted(friendship)
  ...
end

def on_friendship_blocked(friendship)
  ...
end

def on_friendship_destroyed(friendship)
  ...
end