activerecord, refactoring the source code

Question

I have three tables

class User < AR::Base
 has_many :lexemes, :dependent => :destroy
end
class Lexeme < AR::Base
 belongs_to :user
 belongs_to :word
end
class Word < AR::Base
 has_many :lexemes
end

This code is storing the word to Words table and assign it to the user.

word = Word.where(:word=>token).first_or_create
lexeme = @user.lexemes.where(:word_id=>word.id).first_or_create

I don't like my code, so is it possible to improve it? Thanks

Answer 1

class User < AR::Base
 has_many :lexemes, :dependent => :destroy
 has_many :words, :through => :lexemes
end
class Lexeme < AR::Base
 belongs_to :user
 belongs_to :word
end
class Word < AR::Base
 has_many :lexemes
 has_many :users, :through => :lexemes
end

You should normally be able to create word by following code but it seems there is a bug in Rails.

word = @user.words.find_or_create_by_word(token)

Therefore I have changed the model to following. You may remove it when the bug is fixed.

class User < ActiveRecord::Base
 has_many :lexemes
 has_many :words, :through => :lexemes do
 def find_or_create_by_word(token)
 find_by_word(token) || create(:word => token)
 end
 end
end

• Alexey: first_or_create considered to be a clearer alternative for find_or_create_by_xxx
• Can Hanhan: @Alexey it had the same bug, overriding find_or_create_by_xxx was a better option. Thanks for the tip.