has_friends

ATTENTION: This is a new simpler implementation. If you want to use the previous version, get the 1.0 tag.

NOTE: You should have a User model. You should also have a friends_count column on your model. Otherwise, this won't work! You can add as following:

script/generate migration add_friends_count_to_user friends_count:integer

class CreateFriendships < ActiveRecord::Migration
  def self.up
    add_column :users, :friends_count, :integer, :default => 0, :null => false
  end

  def self.down
    remove_column :users, :friends_count
  end
end

Instalation

1. Install the plugin with script/plugin install git://github.com/fnando/has_friends.git

2. Generate following migrations with respective codes:

a) script/generate migration create_relations

class CreateRelationTypes < ActiveRecord::Migration
	def self.up
		create_table :relation_types do |t|
	    t.string :name
	    t.timestamps
		end
	end
	
	add_index :relation_types, :name
	
	def self.down
	drop_table :relation_types
	end
end

b) script/generate migration create_friendships

class CreateFriendships < ActiveRecord::Migration
  def self.up
    create_table :friendships do |t|
      t.references :user, :friend, :friendship_message
      t.datetime :requested_at, :accepted_at, :null => true, :default => nil
      t.string :status
    end

    add_index :friendships, :user_id
    add_index :friendships, :friend_id
    add_index :friendships, :status
  end

  def self.down
    drop_table :friendships
  end
end

c) script/generate migration create_friendship_messages

class CreateFriendshipMessages < ActiveRecord::Migration
  def self.up
    create_table :friendship_messages do |t|
	    t.string :body
	    t.timestamps
	  end
  end

  def self.down
    drop_table :friendship_messages
  end
end

d) script/generate migration create_friendship_relations

class CreateFriendshipRelationTypes < ActiveRecord::Migration
  def self.up
    create_table :friendship_relation_types do |t|
	    t.references :relation, :friendship
	    t.timestamps
	  end
  end

  def self.down
    drop_table :friendship_relation_types
  end
end

3. Run the migrations with rake db:migrate

Usage

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 == Friends::STATUS_REQUESTED

   the friendship has been requested

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

   they're already friends

   else

   ...

   end

LICENSE:

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.