Cannot access model method inside its controller in Rails - ruby-on-rails

Question

In my Rails app, I have a controller tickets_controller.rb and model ticket.rb. For creating a ticket I have the following form,
<%= form_for(#ticket) do |f| %>
<% if #ticket.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#ticket.errors.count, "error") %> prohibited this ticket from being saved:</h2>
<ul>
<% #ticket.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= f.label :ref_no, "Reference Number"%><br/>
<%= f.text_field :ref_no%><br />
<%= f.label :category, "Type of Request"%><br/>
<%= f.text_field :category_id %><br />
<%= f.label :issue, "Issue"%><br/>
<%= f.text_area :issue%><br />
<%= f.label :ticket_priority, "Priority level"%><br/>
<%= f.text_field :ticket_priority_id %><br />
<%= f.label :ticket_status, "Current Status"%><br/>
<%= f.text_field :ticket_status_id %><br />
<%= f.label :project, "Project"%><br/>
<%= f.text_field :project_id %><br />
<div class="actions">
<%= f.submit %>
</div>
<% end %>
I want to create a unique random reference number on the form_load (ticket/new), and it should be appended to Reference Number text field. While creating a new reference number, it should check the tickets table for duplication. So I have the following model,
ticket.rb
class Ticket < ActiveRecord::Base
attr_accessible :issue, :ticket_status_id, :ticket_priority_id, :ref_no, :category_id, :project_id
has_many :ticket_statuses , :through => :ticket_histories
has_one :ticket_priority
belongs_to :user
before_create :generate_token
protected
def generate_num
self.token = loop do
random_token = random(1000000000)
break random_token unless Ticket.exists?(:ref_no => random_token)
end
end
end
and
tickets_controller.rb
class TicketsController < ApplicationController
before_filter :authenticate_user!
#load_and_authorize_resource
def index
#tickets = Ticket.all
respond_to do |format|
format.html # index.html.erb
format.json { render :json => #tickets }
end
end
def show
#ticket = Ticket.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render :json => #ticket }
end
end
def new
#ticket = Ticket.new
#ref_no = Ticket.generate_num
#categories = Category.all
#status = TicketStatus.first
#priorities = TicketPriority.all
respond_to do |format|
format.html # new.html.erb
format.json { render :json => #ticket }
end
end
def edit
#ticket = Ticket.find(params[:id])
end
def create
#ticket = Ticket.new(params[:ticket])
respond_to do |format|
if #ticket.save
format.html { redirect_to #ticket, :notice => 'Ticket was successfully created.' }
format.json { render :json => #ticket, :status => :created, :location => #ticket }
else
format.html { render :action => "new" }
format.json { render :json => #ticket.errors, :status => :unprocessable_entity }
end
end
end
def update
#ticket = Ticket.find(params[:id])
respond_to do |format|
if #ticket.update_attributes(params[:ticket])
format.html { redirect_to #ticket, :notice => 'Ticket was successfully updated.' }
format.json { head :no_content }
else
format.html { render :action => "edit" }
format.json { render :json => #ticket.errors, :status => :unprocessable_entity }
end
end
end
def destroy
#ticket = Ticket.find(params[:id])
#ticket.destroy
respond_to do |format|
format.html { redirect_to tickets_url }
format.json { head :no_content }
end
end
end
When I run my app, I am getting the following error. Can anyone help?
NoMethodError in TicketsController#new
undefined method `generate_num' for #<Class:0x7f5cdc1f21c0>
Rails.root: /home/local/Rajesh/ticket_system
Application Trace | Framework Trace | Full Trace
app/controllers/tickets_controller.rb:27:in `new'

Answer 1

Change your model method generate_num to self.generate_num.
def self.generate_num
token = loop do
random_token = random(1000000000)
break random_token unless Ticket.exists?(:ref_no => random_token)
end
end

Answer 2

You have defined and instance method and you are calling it using Class
Call method using object
#ticket.generate_num