can't save to database with hidden field - ruby-on-rails

Question

I have 2 models, one of patients and another of indicadions, I think I have the relationships between the models correctly placed, what I cannot make it work is that the patient_id is placed in the hidden field
my models:
patient: has_many :prescription, dependent: :destroy
indication: belongs_to :patient
my view:
<%= form_with(model: prescription) do |form| %>
<% if prescription.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(prescription.errors.count, "error") %> prohibited this prescription from being saved:</h2>
<ul>
<% prescription.errors.each do |error| %>
<li><%= error.full_message %></li>
<% end %>
</ul>
</div>
<% end %>
<%= form.hidden_field :patient_id, value: "patient_id" %>
<div class="form-group">
<%= form.label :content %>
<%= form.text_area :content, class:'form-control' %>
</div>
<%= form.submit "SAVE",class:'btn save' %>
<% end %>
The controller:
class PrescriptionsController < ApplicationController
before_action :set_prescription, only: %i[ show edit update destroy ]
# GET /prescriptions or /prescriptions.json
def index
#prescriptions = Prescription.all
end
# GET /prescriptions/1 or /prescriptions/1.json
def show
end
# GET /prescriptions/new
def new
#prescription = Prescription.new
end
# GET /prescriptions/1/edit
def edit
end
# POST /prescriptions or /prescriptions.json
def create
#prescription = Prescription.new(prescription_params)
respond_to do |format|
if #prescription.save
format.html { redirect_to #prescription, notice: "La receta se creó con éxito." }
format.json { render :show, status: :created, location: #prescription }
else
format.html { render :new, status: :unprocessable_entity }
format.json { render json: #prescription.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /prescriptions/1 or /prescriptions/1.json
def update
respond_to do |format|
if #prescription.update(prescription_params)
format.html { redirect_to #prescription, notice: "Prescription was successfully updated." }
format.json { render :show, status: :ok, location: #prescription }
else
format.html { render :edit, status: :unprocessable_entity }
format.json { render json: #prescription.errors, status: :unprocessable_entity }
end
end
end
# DELETE /prescriptions/1 or /prescriptions/1.json
def destroy
#prescription.destroy
respond_to do |format|
format.html { redirect_to prescriptions_url, notice: "Prescription was successfully destroyed." }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_prescription
#prescription = Prescription.find(params[:id])
end
# Only allow a list of trusted parameters through.
def prescription_params
params.require(:prescription).permit(:content, :patient_id)
end
end

Answer 1

Instead of using a hidden input you might actually want to nest the routes to makes the relationship explicit instead of implicit:
resources :patients do
resources :perscriptions, shallow: true
end
class PrescriptionsController < ApplicationController
before_action :set_patient
before_action :set_prescription, only: %i[ show edit update destroy ]
# GET /patients/1/prescriptions or /patients/1/prescriptions.json
def index
#prescriptions = #patient.perscriptions
end
# GET /prescriptions/1 or /prescriptions/1.json
def show
end
# GET /patients/1/prescriptions/new
def new
#prescription = Prescription.new
end
# GET /prescriptions/1/edit
def edit
end
# POST /patients/1/prescriptions or /patients/1/prescriptions.json
def create
#prescription = #patient.perscriptions.new(prescription_params)
respond_to do |format|
if #prescription.save
format.html { redirect_to #prescription, notice: "La receta se creó con éxito." }
format.json { render :show, status: :created, location: #prescription }
else
format.html { render :new, status: :unprocessable_entity }
format.json { render json: #prescription.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /prescriptions/1 or /prescriptions/1.json
def update
respond_to do |format|
if #prescription.update(prescription_params)
format.html { redirect_to #prescription, notice: "Prescription was successfully updated." }
format.json { render :show, status: :ok, location: #prescription }
else
format.html { render :edit, status: :unprocessable_entity }
format.json { render json: #prescription.errors, status: :unprocessable_entity }
end
end
end
# DELETE /prescriptions/1 or /prescriptions/1.json
def destroy
#prescription.destroy
respond_to do |format|
format.html { redirect_to prescriptions_url, notice: "Prescription was successfully destroyed." }
format.json { head :no_content }
end
end
private
def set_patient
#patient = Patient.find(params[:patient_id])
end
def set_prescription
#prescription = Prescription.find(params[:id])
end
# Only allow a list of trusted parameters through.
def prescription_params
params.require(:prescription).permit(:content)
end
end
<%= form_with(model: [#patient, #perscription]) do |form| %>
<% if prescription.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(prescription.errors.count, "error") %> prohibited this prescription from being saved:</h2>
<ul>
<% prescription.errors.each do |error| %>
<li><%= error.full_message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="form-group">
<%= form.label :content %>
<%= form.text_area :content, class:'form-control' %>
</div>
<%= form.submit "SAVE", class:'btn save' %>
<% end %>