has_many :through and collection_select rails form

问题

I have tried all of the solutions to similar problems and haven't gotten this one figured out.

I have a has_many :through relationship between 'Clinician', and 'Patient' with a joined model 'CareGroupAssignment'. None of the methods I have tried so far been able to save the clinician to patient association. I would like to have a patient be able to have multiple clinicians associated with it and clinicians will have multiple patients.

clinician.rb (simplified)

class Clinician < ActiveRecord::Base
    belongs_to :care_group

    has_many :patients ,:through=> :care_group_assignments
    has_many :care_group_assignments, :dependent => :destroy

    belongs_to :user
    accepts_nested_attributes_for :user,  :allow_destroy => true
end

patient.rb

class Patient < ActiveRecord::Base
    belongs_to :care_group

    has_many :clinicians ,:through=> :care_group_assignments
    has_many :care_group_assignments

    belongs_to :user
    accepts_nested_attributes_for :user,  :allow_destroy => true
end

care_group_assignments.rb

class CareGroupAssignment < ActiveRecord::Base
    belongs_to :clinician
    belongs_to :patient
end

I first tried to follow the example from Railscasts PRO #17- HABTM Checkboxes to at least start getting the data collected and to have the models set up correctly. Below is the form with the checkboxes for each clinician as described in the RailsCast, checkboxes show up and the data is sent but not stored (can't figure out why).

patient new.html.erb form

<%= form_for @patient do |form| %>

  <%= form.fields_for :user do |builder| %>
   <div class="form-group">
      <%= builder.label "Email or Username" %>
      <%= builder.text_field :email, class: "form-control" %>
    </div>
    <div class="form-group">
      <%= builder.label :password %>
      <%= builder.password_field :password, class: "form-control" %>
    </div>
  <% end %>

  <div class="form-group">
    <%= form.label :first_name %>
    <%= form.text_field :first_name, class: "form-control", placeholder: "First name" %>
  </div>

  <div class="form-group">
    <%= form.label :last_name %>
    <%= form.text_field :last_name, class: "form-control", placeholder: "Last name" %>
  </div>

  <div class="form-group">
    <% Clinician.where(care_group_id: @care_group.id).each do |clinician| %>
      <%= check_box_tag "patient[clinician_ids][]", clinician.id, @patient.clinician_ids.include?(clinician.id), id: dom_id(clinician) %>
      <%= label_tag dom_id(clinician), clinician.full_name %><br>
    <% end %>
  </div>

  <%= form.button 'Create Patient', class: "btn btn-u btn-success" %>
<% end %>

Next, I tried the collection_select answer to this question. This creates a badly formatted list where only one clinician can be selected. The data seems to get sent but again doesn't save.

patient new.html.erb form

  <div class="form-group">
    <%= collection_select(:patient, :clinician_ids, 
      Clinician.where(care_group_id: @care_group.id).order("first_name asc"), 
      :id, :full_name, {:selected => @patient.clinician_ids, :include_blank => true}, {:multiple => true}) %>
  </div>

Lastly, I copied what was done in this questions/solution. Also isn't formatted as a normal collection_select dropdown but instead a list with a boarder around it where only one clinician can be selected.

patient new.html.erb form

  <div class="form-group">
    <% Clinician.where(care_group_id: @care_group.id).each do |clinician| %>
      <%= check_box_tag "patient[clinician_ids][]", clinician.id, @patient.clinician_ids.include?(clinician.id), id: dom_id(clinician) %>
      <%= label_tag dom_id(clinician), clinician.full_name %><br>
    <% end %>
  </div>

None of these methods have so far been able to save the clinician to patient association.

patient_controller.rb

def new
  @patient = Patient.new
  @user = User.new
  @patient.build_user

  @care_group = current_clinician.care_group
end

def create
  @patient = Patient.create(patient_params)
  @patient.care_group = current_clinician.care_group

  if @patient.save
    redirect_to patient_path(@patient), notice: "New patient created!"
  else
    render "new"
  end
end

def show
 @patient = Patient.find_by(id: params["id"])
end

private
 def patient_params
  params.require(:patient).permit({:clinician_ids => [:id]},:first_name,:last_name,:user_id,:care_group_id, user_attributes: [ :email, :password, :patient_id, :clinician_id ])
 end

I plan to display the clinicians associated with a patient on the patient show page:

patient show.html.erb

<strong>Shared with:</strong>
 <% @patient.clinicians.each do |clinician| %>
  <%= clinician.full_name %><
 <% end %>

This works if I seed the database but since the data doesn't seem to be stored, nothing is showing up.

Rails 4.1.8, ruby 2.2.1p85, PostgreSQL

Thanks

回答1:

Found the answer on another question I asked:

problem is this line in the controller:

params.require(:patient).permit({:clinician_ids => [:id]}...

It should be:

params.require(:patient).permit({:clinician_ids => []}...

来源：https://stackoverflow.com/questions/32344096/has-many-through-and-collection-select-rails-form