NoMethodError (undefined method `persist' for #<PersonalTrainer:0x000055625dbfd7a8> when trying to create a table entry

Question

I am trying to add items to a table in rails but getting the error it the title. It works for me locally but on heroku it gives me this error. I have seen a couple of solution but none seem to work. This is my controller:

require './app/policies/personal_trainer_policy'
class PersonalTrainersController < ApplicationController
  before_action :set_personal_trainer, only: [:show, :edit, :update, :destroy]

  # GET /personal_trainers
  # GET /personal_trainers.json
  def index
    @personal_trainers = PersonalTrainer.all

  end

  # GET /personal_trainers/1
  # GET /personal_trainers/1.json
  def show

  end

  # GET /personal_trainers/new
  def new
    @personal_trainer = PersonalTrainer.new
  end

  # GET /personal_trainers/1/edit
  def edit
  end
  def personal_trainer_policy
    @_personal_trainer_policy ||= PersonalTrainerPolicy.new(personal_trainer)
  end 

  # POST /personal_trainers
  # POST /personal_trainers.json
  def create
    @personal_trainer = PersonalTrainer.new(personal_trainer_params)
    authorize @personal_trainer
    if @personal_trainer.persist
      render json: @personal_trainer.record
    else
      render json: @personal_trainer.errors, status: :unpocessably_entity
    end

    respond_to do |format|
      if @personal_trainer.save
        format.html { redirect_to @personal_trainer, notice: 'Personal trainer was successfully created.' }
        format.json { render :show, status: :created, location: @personal_trainer }
      else
        format.html { render :new }
        format.json { render json: @personal_trainer.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /personal_trainers/1
  # PATCH/PUT /personal_trainers/1.json
  def update
    authorize @personal_trainer

    respond_to do |format|
      if @personal_trainer.update(personal_trainer_params)
        format.html { redirect_to @personal_trainer, notice: 'Personal trainer was successfully updated.' }
        format.json { render :show, status: :ok, location: @personal_trainer }
      else
        format.html { render :edit }
        format.json { render json: @personal_trainer.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /personal_trainers/1
  # DELETE /personal_trainers/1.json
  def destroy
    authorize @personal_trainer

    @personal_trainer.destroy
    respond_to do |format|
      format.html { redirect_to personal_trainers_url, notice: 'Personal trainer was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_personal_trainer
      @personal_trainer = PersonalTrainer.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def personal_trainer_params
      params.require(:personal_trainer).permit(:firstName, :secondName, :desription, :amountOfClients)
    end
end

The controller was generated using a scaffold. This is my erb file:

<p id="notice"><%= notice %></p>

<h1 class = "title">Personal Trainers</h1>
<div class = "page-conatiner">

<table class = "table">
  <thead>
  <%= stylesheet_link_tag 'gym_classes', media: 'all', 'data-turbolinks-track': 'reload' %>
    <tr>
      <th>First Name</th>
      <th>Second Name</th>
      <th>Desription</th>
      <th>Amount of Clients</th>
      <th colspan="3"></th>
    </tr>
  </thead>

  <tbody>
    <% @personal_trainers.each do |personal_trainer| %>


      <tr>
        <td><%= personal_trainer.firstName %></td>
        <td><%= personal_trainer.secondName %></td>

        <td><%= personal_trainer.desription %></td>
        <td><%= personal_trainer.amountOfClients %></td>
        <td><%= link_to 'Show', personal_trainer %></td>
        <td><%= link_to 'Edit', edit_personal_trainer_path(personal_trainer) %></td>
        <td><%= link_to 'Destroy', personal_trainer, method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>

<br>

<% if current_user.admin == true %>
<%= link_to 'New Personal Trainer', new_personal_trainer_path %>
<% end %>
</div>

and this is my model:

class PersonalTrainer < ApplicationRecord
    has_many :gym_class_final
    has_many :pt_client

end

I have it set so that admins can only create new items using a policy and adding authorise @personal_trainer. I wonder if this has something to do with the error. I just dont understand how it would work locally but not when its deployed. Any suggestions.

Answer 1

persist is not a valid method on an active record object, you're looking for save :

if @personal_trainer.save
  render json: @personal_trainer.record
else
  render json: @personal_trainer.errors, status: :unpocessably_entity
end

For more information on what methods are available for active record persistence, see https://api.rubyonrails.org/classes/ActiveRecord/Persistence.html (Rails 6)