set up helper_method :current_patient Rails 4

Question

How can I set a helper method in my app that when I call it, recognizes a current_patient from a certain medic (can be multiple medics, and multiple patients for a medic) and access to patient :id, this would help me to associate:

Medic with a Patient with a Consultations for current_patient

I need to access on a patient and set id (patient) on a Consultation table foreign key :patient_id

in my create action in the controller I have:

def create
  @consultation = Consultation.new(consultation_params.merge({:patient_id => current_patient}))
  respond_to ...
end

Is a helper method a good way to do this?

How can I do this?

my models:

class Medic < ActiveRecord::Base
  has_many :patients
end

class Patient < ActiveRecord::Base
  belongs_to :medic, :foreign_key => :medic_id
  has_many :consultations
  accepts_nested_attributes_for :consultations
end

class Consultation < ActiveRecord::Base
  belongs_to :patient, :foreign_key => :patient_id
end

Thanks for help

Answer 1

Lets start with the routes:

resources :patients do
  resources :consultations
end

This will give us the routes for consultations nested under the patient:

                   Prefix Verb   URI Pattern                                            Controller#Action
    patient_consultations GET    /patients/:patient_id/consultations(.:format)          consultations#index
                          POST   /patients/:patient_id/consultations(.:format)          consultations#create
 new_patient_consultation GET    /patients/:patient_id/consultations/new(.:format)      consultations#new
edit_patient_consultation GET    /patients/:patient_id/consultations/:id/edit(.:format) consultations#edit
     patient_consultation GET    /patients/:patient_id/consultations/:id(.:format)      consultations#show
                          PATCH  /patients/:patient_id/consultations/:id(.:format)      consultations#update
                          PUT    /patients/:patient_id/consultations/:id(.:format)      consultations#update
                          DELETE /patients/:patient_id/consultations/:id(.:format)      consultations#destroy

So lets say we have a PatientsController#index method which shows all the patients. And in our view we have something like this:

<% @patients.each do |patient| %>
  <li>
    <p><%= patient.name %></p>
  </li>
<% end %>

So lets add a link to create the consultation:

<% @patients.each do |patient| %>
  <p><%= patient.name %></p>
  <ul class="actions">
    <li>
     <%= link_to "New consultation",
                 new_patient_consultation_path(patient) %>
    </li>
  </ul>
<% end %>

Clicking the link would take us to /patients/6/consultations/new .

So in our ConsultationsController we can access the patient id from the params:

class ConsultationsController < ApplicationController

  # We use a callback so that we don't need to do 
  # @patient = Patient.find(params[:id]) in every action
  before_action :set_patient 

  # GET /patients/:patient_id/consultations/new
  def new
    @consultation = @patient.consultations.new
  end

  # POST /patients/:patient_id/consultations
  def create
    @consultation = @patient.consultations.new(consultation_params)

    # ...
  end

  # ...

  private
    def set_patient
      @patient = Patient.find(params[:patient_id])
    end
    # ...
end

set_patient is just a private method belonging to the controller. This is not really a case where you would use a helper method.

Its often done when dealing with dealing with authentication since you are getting current_user from the session - independently from the params. If you are creating a helper method it should work everywhere.

There is one final thing you need to to get this to work, the form needs to point to /patients/:patient_id/consultations .

# app/views/consultations/_form.html.erb
<% form_for [@patient, @consultation] do |f| %>
   # .. rails does all the magic figuring out the url.
<% end %>

• http://guides.rubyonrails.org/routing.html#nested-resources