ATTENTION: This is a Rails 3 implementation.

NOTE: You should have a User model. When you execute the plugin generator, I'll add a column friends_count on users' table.

1. Add a gem line to your Gemfile. gem 'has_friends-rails3', :require => 'has_friends'

2. Execute the plugin generator rails g has_friends:migration

3. Run the migrations with rake db:migrate

1. Add the method call has_friends to your model.

   class User < ActiveRecord::Base has_friends end

   john = User.find_by_login 'john' mary = User.find_by_login 'mary' paul = User.find_by_login 'paul'

   John wants to be friend with Mary

   always return a friendship object

   john.be_friends_with(mary, "Hi Mary! I have worked with you on Meroy Merlin!")

   Creating a new Relation kind

   RelationType.create(:name => "coworker")

   You can pass kind of relationship, when...

   john.be_friends_with(mary, "Hi Mary! I have worked with you on Meroy Merlin!", [:coworker])

   if you specify a non existent Relation,

   it will create a new Relation

   and associate then to friendship

   john.be_friends_with(mary, "Hi Mary! I have worked with you on Meroy Merlin!", [:coworker, :friend])

   In this case, friend is a new relation

   are they friends?

   john.friends?(mary) ==> false

   get the friendship object

   john.friendship_for(mary)

   Mary accepts John's request if it exists...

   mary.accept_friendship_with(john) mary.friends?(john) ==> true

   either if Mary request John's friendship, then they will be friends automatically.

   mary.be_friends_with(john) mary.friends?(john) ==> true

   Mary can reject John's friendship.

   mary.remove_friendship_with(john)

   check if an user is the current user, so it can

   be differently presented

   mary.friends.each {|friend| friend.is?(current_user) }

   if you're dealing with a friendship object,

   the following methods are available

   friendship.accept!

   You can specify relations when accept a friendship, so...

   friendship.accept!([:friend])

   If you want to accept friendship and clear current relations...

   friendship.accept!([])

   the be_friends_with method returns 2 params: friendship object and status.

   the friendship object will be present only when the friendship is created

   (that is, when is requested for the first time)

   STATUS_ALREADY_FRIENDS # => users are already friends

   STATUS_ALREADY_REQUESTED # => user has already requested friendship

   STATUS_IS_YOU # => user is trying add himself as friend

   STATUS_FRIEND_IS_REQUIRED # => friend argument is missing

   STATUS_FRIENDSHIP_ACCEPTED # => friendship has been accepted

   STATUS_REQUESTED # => friendship has been requested

   friendship, status = mary.be_friends_with(john)

   if status == Friendship::STATUS_REQUESTED

   the friendship has been requested

   Mailer.deliver_friendship_request(friendship) elsif status == Friendship::STATUS_ALREADY_FRIENDS

   they're already friends

   else

   ...

   end

(The MIT License)

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