How to obtain different type of collections for the same Model in an Association in Rails 4?

Question

In my application I have a User model and a Job model. Users can post many jobs, and other users can apply to these jobs by posting proposals. The job poster can then select a user from the list of users who have applied, later this user will be assigned to work on this job.

This means that the Job model should have two kinds of foreign keys for User, maybe something like poster_id and worker_id.

Currently my models look like this:

class Job < ActiveRecord::Base
   belongs_to :user
   has_many :proposals, dependent: :destroy
end

class User < ActiveRecord::Base
   has_many :jobs, dependent: :destroy
   has_many :proposals, through: :jobs
end

class Proposal < ActiveRecord::Base
    belongs_to :job
    belongs_to :user
end

My question is, what are the correct associations between these models in order to work the way I described?

For example, I need to access the posted jobs of a certain user, as well as the jobs this user is subscribed to (worker_id). These are different collections, but of the same model Job...

Something like:

@user.posted_jobs.all
@user.current_jobs.all

These would return different Jobs for the same @user.

Would really appreciate help.

Can a job have more than one worker user? – tirdadc May 06 '15 at 12:40 — tirdadc, May 06 '15 at 12:40

score 1 · Accepted Answer · edited May 23 '17 at 12:31

Assuming your Job can only have one worker that is set when a Proposal is accepted, you'd want something like this:

class Job < ActiveRecord::Base
   belongs_to :poster, class_name: 'User', foreign_key: 'poster_id'
   belongs_to :worker, class_name: 'User', foreign_key: 'worker_id'
   has_many :proposals, dependent: :destroy
end

class User < ActiveRecord::Base
   has_many :posted_jobs, class_name: 'Job', foreign_key: 'poster_id', dependent: :destroy
   has_many :current_jobs, class_name: 'Job', foreign_key: 'worker_id'
   has_many :proposals, through: :jobs
end

class Proposal < ActiveRecord::Base
    belongs_to :job
    belongs_to :user
end

With this approach, you can get user.posted_jobs and user.current_jobs.

See this: Same Model for Two belongs_to Associations

score 0 · Answer 2 · answered May 06 '15 at 11:09

0

you can use group_by..example like this if you have Job and Proposal model..so you can do something like..

@results = @results.group_by(&:class)
@jobs = @results[Job]
@proposals = @results[Proposal]

answered May 06 '15 at 11:09

Milind

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Francesco Pirrone · Answer 3 · 2015-05-06T13:09:05.543

So

@user.jobs.all #list of all jobs posted by the user

If u want the list of jobs subscribed by the user you have to do some more work

#subscribeds = [] if u want only the list of jobs subscribeds but not posted
subscribeds = @user.jobs.all # if u want the list of all jobs related to user
@user.proposals.each do |proposal| 
     @subscribeds << proposal.job
end

EDIT

For a direct way to handle the models you can go this way:

class User < ActiveRecord::Base
   has_many :proposals
   has_many :subscribeds_jobs, class_name: 'Job', through: :proposals
   has_many :jobs
   def all_jobs
      return self.jobs.all + self.subscribeds.jobs.all
   end
end

This way Rails will recover the proposals jobs by records association.

Thanks for your response. Does this mean that the subscribed jobs cannot be handled as a model collection like @user.jobs, and has to be 'accessed' the way you specified? — Andres, May 06 '15 at 12:23

How to obtain different type of collections for the same Model in an Association in Rails 4?

3 Answers3