has_many :through and has_one :through associations

[Wael Nasreddine]

Hello,

First I'm using Rails 3.1 from the 3-1-stable branch updated an hour ago.

I'm developing an application where I have 3 essential models User, Company and Job, Here's the relevant part of the models:

class User < ActiveRecord::Base

  has_many :companies_users, class_name: "CompaniesUsers"

  has_many :companies, :through => :companies_users, :source => :company

end

class Company < ActiveRecord::Base

  has_many :companies_users, class_name: "CompaniesUsers"

  has_many :employees, :through => :companies_users, :source => :user

  has_many :jobs, :dependent => :destroy

end

class Job < ActiveRecord::Base

  belongs_to :company, :counter_cache => true

end

class CompaniesUsers < ActiveRecord::Base

  belongs_to :company

  belongs_to :user

end

The code works just fine, but I have been wondering if it's possible to:

I want to link a job with an employer, so think of this scenario: A user John who's an employee at Example, he posted the job Rails Developer, so I want to access @job.employer and it should get me back the user John, in other words:

@user = User.find_by_name('john')

@job   = Job.find(1)

@job.employer == @user       #=> true

So I thought of two possible solutions

First solution

==========

class Job

  has_one :employer, :through => :employers

end

class User

  has_many :jobs, :through => :employers

end

class Employer

  belongs_to :job

  belongs_to :user

end

Second solution

=============

class Job

  has_one :employer, :class_name => "User"

end

class User

  belongs_to :job

end

Which route should I go? Is my code right ?

I have another question, how to get rid of the class_name => "CompaniesUsers" option passed to has_many, should the class be Singular or Plural ? Should I rename it to something like Employees ?

P.S: I posted the same question to Stackoverflow

-- 

Wael Nasreddine: Design & Coding at TechnoGate
contact | wael.na...@gmail.com - +33.6.31.17.41.10 | skype - eMxyzptlk