Membuat Aplikasi POS dengan Ruby on Rails 4 part 2

Pada post sebelumnya  kita sudah mengerjakan desain dan model aplikasi, sekarang kita akan lanjutkan ke fungsi dan  bagian yang belum lengkapnya.

Fungsi Generate Code

Product mempunyai attribut code dan codenya nanti akan di generate secara otomatis.
Attribut ini nantinya bisa digunakan untuk barcode.

1. Pada folder view/productIndex dan formnya dirubah
2. File _form.html.erb bagian user dan codenya di hilangkan 

 <%= form_for(@product) do |f| %>  
  <% if @product.errors.any? %>  
   <div id="error_explanation">  
    <h2><%= pluralize(@product.errors.count, "error") %> prohibited this product from being saved:</h2>  
    <ul>  
    <% @product.errors.full_messages.each do |message| %>  
     <li><%= message %></li>  
    <% end %>  
    </ul>  
   </div>  
  <% end %>  
  <div class="field">  
   <%= f.label :name %><br>  
   <%= f.text_field :name %>  
  </div>  
  <div class="field">  
   <%= f.label :price %><br>  
   <%= f.text_field :price %>  
  </div>  
  <div class="actions">  
   <%= f.submit %>  
  </div>  
 <% end %>  

3. Untuk index.html.erb codenya seperti berikut

 <h1>Listing Product</h1>  
 <table class="table table-striped">  
  <thead>  
   <tr>  
    <th>Name</th>  
    <th>Code</th>  
    <th>Price</th>  
    <th></th>  
    <th colspan="3"></th>  
   </tr>  
  </thead>  
  <tbody>  
   <% @products.each do |product| %>  
    <tr>  
     <td><%= product.name %></td>  
     <td><%= product.code %></td>  
     <td><%= product.price %></td>  
     <td><%= link_to 'Show', product %></td>  
     <td><%= link_to 'Edit', edit_product_path(product) %></td>  
     <td>  
       <%= link_to 'Destroy', product, method: :delete, data: { confirm: 'Are you sure?' } %>  
     </td>  
    </tr>  
   <% end %>  
  </tbody>  
 </table>  
 <br>  
 <%= link_to 'New Product', new_product_path %>  

4. Tambahkan code pada model product

  before_create :set_code  
  def generate_code(size = 6)  
   charset = %w{ 2 3 4 6 7 9 A C D E F G H J K M N P Q R T V W X Y Z}  
   (0...size).map{ charset.to_a[rand(charset.size)] }.join  
  end  
  def set_code  
   self.code = generate_code(6)  
  end  

5. Selanjutnya di controller productnya  tambahkan baris berikut pada method create

 @product = Product.new(product_params)   
 @product.user_id = current_user.id #tambahkan code ini setelah code diatas  

6. Lakukan input data di url http://localhost:3000/products/new

Membuat Nested Form 

1. Edit model sale.rb tambahkan code berikut

 has_many :items  
 accepts_nested_attributes_for :items, allow_destroy: true  

2. Edit partial _form.html.erb di dalam folder view/sales

 <%= form_for(@sale) do |f| %>  
  <% if @sale.errors.any? %>  
   <div id="error_explanation">  
    <h2><%= pluralize(@sale.errors.count, "error") %> prohibited this sale from being saved:</h2>  
    <ul>  
    <% @sale.errors.full_messages.each do |message| %>  
     <li><%= message %></li>  
    <% end %>  
    </ul>  
   </div>  
  <% end %>  
  <div class="field">  
   <%= f.label :name %><br>  
   <%= f.text_field :name %>  
  </div>  
  <%= f.fields_for :items do |builder| %>   
    <%= render 'item_fields', f: builder %>   
  <% end %>   
  <%= link_to_add_fields "Add Item", f, :items %>   
  <div class="actions">  
   <%= f.submit %>  
  </div>  
 <% end %>  
 <script type="text/javascript">   
  jQuery(function() {   
   $('form').on('click', '.remove_fields', function(event) {   
   $(this).prev('input[type=hidden]').val('1');   
   $(this).closest('fieldset').hide();   
   return event.preventDefault();   
   });   
   return $('form').on('click', '.add_fields', function(event) {   
   var regexp, time;   
   time = new Date().getTime();   
   regexp = new RegExp($(this).data('id'), 'g');   
   $(this).before($(this).data('fields').replace(regexp, time));   
   return event.preventDefault();   
   });   
  });   
  </script>   

3. Edit aplication_helper.rb tambahkan code berikut

  def link_to_add_fields(name, f, association)  
   new_object = f.object.send(association).klass.new  
   id = new_object.object_id  
   fields = f.fields_for(association, new_object, child_index: id) do |builder|  
    render(association.to_s.singularize + "_fields", f: builder)  
   end  
   link_to(name, '#', class: "add_fields", data: {id: id, fields: fields.gsub("\n", "")})  
  end 

4. buat file partial _item_fields.html.erb di folder sales/app/views/sales/ isinya seperti berikut

 <fieldset>  
  <%= f.label :product, "Product" %>  
  <%= f.collection_select :product_id, Product.all, :id, :name %>  
  <%= f.label :quantity, "Quantity" %>  
  <%= f.text_field :quantity, class: 'padli' %>  
  <%= f.hidden_field :_destroy %>  
  <%= link_to "remove", '#', class: "remove_fields" %>  
 </fieldset>  

5. Periksa di http://localhost:3000/sales/new hasilnya akan seperti gambar berikut
   
   
   

Fungsi Hitung Penjualan 

Tadikan di form penjualan kita sudah bisa input item dan jumlahnya,  tapi total penjualanya belum terhitung. Nah sekarang kita akan buat menghitung total nya:

1. Edit model item ketikan code berikut:

  before_save :set_total  
  def set_total  
   if self.quantity.blank?  
    0  
   else  
        self.total = self.quantity * self.product.price  
   end  
  end  
  def subtotal  
   if self.quantity.blank?  
    0  
   else  
        self.quantity * self.product.price  
   end  
  end  

2. Edit model sale untuk menghitung total harga penjualan berikut codenya

  def subtotals  
   self.items.map { |i| i.subtotal }  
  end  
  def total_all  
   subtotals.sum  
  end  

3. Edit controllers sales_controller.rb
4. Tambahkan pada method create code berikut

 @sale = Sale.new(sale_params)  
 @sale.user_id = current_user.id #tambahkan ini setelah code di atas  
 @sale.total = @sale.total_all #tambahkan ini setelah code di atas  

5. Tambahkan parameter yang akan di permit

 params.require(:sale).permit(:name, items_attributes: [:id,:product_id, :price,:quantity,:total,:_destroy])  

6. Lakukan input data penjualan  http://localhost:3000/sales/new tambahkan beberapa item kemudian simpan
7. Periksa apakah total penjualanya terhitung
8. Edit file show di folder view sale

 <p id="notice"><%= notice %></p>  
 <p>  
  <strong>Name:</strong>  
  <%= @sale.name %>  
 </p>  
 <%= link_to 'Edit', edit_sale_path(@sale) %> |  
 <%= link_to 'Back', sales_path %>  
 <h1>Listing Item</h1>  
 <table class="table table-striped">  
  <thead>  
   <tr>  
    <th>Product</th>  
    <th>price</th>  
    <th>quantity</th>  
    <th>total</th>  
    <th></th>  
   </tr>  
  </thead>  
  <tbody>  
   <% @sale.items.each do |item| %>  
    <tr>  
     <td><%= item.product.name %></td>  
     <td><%= item.product.price %></td>  
     <td><%= item.quantity %></td>  
     <td><%= item.total %></td>  
    </tr>  
   <% end %>  
  </tbody>  
 </table>  
 <hr>  
  <p> Total </p>  
  <%= @sale.total%>  
 <hr>  

Mengatur User-Roles

Pada bagian ini kita akan mengatur hak akses user pada aplikasi POS.

1. Generate cancan

$ rails g cancan:ability

2. Tambahkan code di class ability.rb seperti berikut: 

 class Ability  
  include CanCan::Ability  
  def initialize(user)  
   if user.present?  
    if user.role.name == 'admin'  
     can :manage, :all  
    else  
     can :create , Product  
     can :create , Sale  
     can :read, :all  
    end  
   else  
    can :read, :all  
   end  
  end  
 end  

3.  Edit products_controller tambahkan  load and authorize seperti berikut 

 class ProductsController < ApplicationController  
  before_action :set_product, only: [:show, :edit, :update, :destroy]  
  load_and_authorize_resource  
  # GET /products  
  # GET /products.json  
  def index  
   @products = Product.all  
  end  
  # GET /products/1  
  # GET /products/1.json  
  def show  
  end  
  # GET /products/new  
  def new  
   @product = Product.new  
  end  
  # GET /products/1/edit  
  def edit  
  end  
  # POST /products  
  # POST /products.json  
  def create  
   @product = Product.new(product_params)  
   @product.user_id = current_user.id #tambahkan code ini setelah code diatas   
   respond_to do |format|  
    if @product.save  
     format.html { redirect_to @product, notice: 'Product was successfully created.' }  
     format.json { render :show, status: :created, location: @product }  
    else  
     format.html { render :new }  
     format.json { render json: @product.errors, status: :unprocessable_entity }  
    end  
   end  
  end  
  # PATCH/PUT /products/1  
  # PATCH/PUT /products/1.json  
  def update  
   respond_to do |format|  
    if @product.update(product_params)  
     format.html { redirect_to @product, notice: 'Product was successfully updated.' }  
     format.json { render :show, status: :ok, location: @product }  
    else  
     format.html { render :edit }  
     format.json { render json: @product.errors, status: :unprocessable_entity }  
    end  
   end  
  end  
  # DELETE /products/1  
  # DELETE /products/1.json  
  def destroy  
   @product.destroy  
   respond_to do |format|  
    format.html { redirect_to products_url, notice: 'Product was successfully destroyed.' }  
    format.json { head :no_content }  
   end  
  end  
  private  
   # Use callbacks to share common setup or constraints between actions.  
   def set_product  
    @product = Product.find(params[:id])  
   end  
   # Never trust parameters from the scary internet, only allow the white list through.  
   def product_params  
    params.require(:product).permit(:code, :name, :price, :user_id)  
   end  
 end  

4. Edit sales_controller tambahkan  load and authorize seperti berikut

 class SalesController < ApplicationController  
  before_action :set_sale, only: [:show, :edit, :update, :destroy]  
  load_and_authorize_resource  
  # GET /sales  
  # GET /sales.json  
  def index  
   @sales = Sale.all  
  end  
  # GET /sales/1  
  # GET /sales/1.json  
  def show  
  end  
  # GET /sales/new  
  def new  
   @sale = Sale.new  
  end  
  # GET /sales/1/edit  
  def edit  
  end  
  # POST /sales  
  # POST /sales.json  
  def create  
   @sale = Sale.new(sale_params)  
   @sale.user_id = current_user.id #tambahkan ini setelah code di atas   
   @sale.total = @sale.total_all #tambahkan ini setelah code di atas  
   respond_to do |format|  
    if @sale.save  
     format.html { redirect_to @sale, notice: 'Sale was successfully created.' }  
     format.json { render :show, status: :created, location: @sale }  
    else  
     format.html { render :new }  
     format.json { render json: @sale.errors, status: :unprocessable_entity }  
    end  
   end  
  end  
  # PATCH/PUT /sales/1  
  # PATCH/PUT /sales/1.json  
  def update  
   respond_to do |format|  
    if @sale.update(sale_params)  
     format.html { redirect_to @sale, notice: 'Sale was successfully updated.' }  
     format.json { render :show, status: :ok, location: @sale }  
    else  
     format.html { render :edit }  
     format.json { render json: @sale.errors, status: :unprocessable_entity }  
    end  
   end  
  end  
  # DELETE /sales/1  
  # DELETE /sales/1.json  
  def destroy  
   @sale.destroy  
   respond_to do |format|  
    format.html { redirect_to sales_url, notice: 'Sale was successfully destroyed.' }  
    format.json { head :no_content }  
   end  
  end  
  private  
   # Use callbacks to share common setup or constraints between actions.  
   def set_sale  
    @sale = Sale.find(params[:id])  
   end  
   # Never trust parameters from the scary internet, only allow the white list through.  
   def sale_params  
    params.require(:sale).permit(:name, items_attributes: [:id,:product_id, :price,:quantity,:total,:_destroy])  
   end  
 end  

5. Edit aplication_controller tambahkan baris code berikut

  rescue_from CanCan::AccessDenied do |exception|  
   flash[:error] = "Access denied."  
   redirect_to root_url  
  end  

6. Untuk link tinggal di kasih kondisi seperti berikut

     <td><%= link_to 'Show', sale %></td>  
     <% if can? :update, Sale %>  
      <td><%= link_to 'Edit', edit_sale_path(sale) %></td>  
     <%end%>  
     <% if can? :destroy, Sale %>  
      <td><%= link_to 'Destroy', sale, method: :delete, data: { confirm: 'Are you sure?' } %></td>  
     <% end %>  

Public Activities

Fitur ini bertujuan untuk mencatat aktifitas user pada aplikasi. Sehingga apabila ada karyawan yang melakukan aktifitas pelanggaran / kecurangan, sistem admin bisa melihat bukti aktifitasnya.

1. Generate public_activity

$ rails g public_activity:migration

$ rake db:migrate

2. Di aplication_controller.rb tambahkan code

 include PublicActivity::StoreController  

3. Di model product.rb dan sale.rb  tambahkan code berikut

 include PublicActivity::Model  
  tracked owner: ->(controller, model) { controller && controller.current_user}  

4. Buat controller untuk  activities

$ rails g controller activities 

5. Di routesnya tambahkan code

  root to: 'home#index'  
  resources :activities  

6. Di controllernya tambahkan code berikut 

 class ActivitiesController < ApplicationController  
  def index  
   @activities = PublicActivity::Activity.order("created_at desc")  
  end  
 end  

7. Di viewnya buat file index.html.erb di folder activities isi dengan code berikut

 <h1>Listing Activities</h1>  
 <table class="table table-striped table-bordered table-condensed sortable">  
   <thead>  
     <tr>  
       <th><%= "Activities"%></th>  
     </tr>  
   </thead>  
   <tbody>  
        <% @activities.each do |activity| %>  
     <tr>  
       <td valign="top">   
         <%= activity.owner.email %>  
         <%= render_activity activity %>  
       </td>  
     </tr>  
     <% end %>  
   </tbody>  
   <tfoot>  
     <tr>  
       <td colspan="3"></td>  
     </tr>  
   </tfoot>  
 </table>  

8. Buat folder public_activity di view
9. Di dalam folder public_activity buat folder product dan sale
10. Di dalam folder product dan sale buat file html partial _create.html.erb ,_update.html.erb, _destroy.html.erb
11. Create.html.erb  codenya seperti berikut

 added product  
 <% if activity.trackable %>  
  <%= link_to activity.trackable.name, product_path(activity.trackable.id) %>  
 <% else %>  
  which has since been removed  
 <% end %>  

12. _update.html.erb

 Updated product  
 <% if activity.trackable %>  
  <%= link_to activity.trackable.name, product_path(activity.trackable.id) %>  
 <% else %>  
  which has since been removed  
 <% end %>  

13. _destroy.html.erb

 removed a produc  

14. Masuk folder layout dan edit file application.html.erb tambahkan code dibawah class nav navbar-nav

 ·<li><%= link_to "All Activities", activities_path %></li>  

15. Terakhir lakukan proses insert, update dan delete di http://localhost:3000/sales dan http://localhost:3000/products
16. Hasilnya  bisa di akses di http://localhost:3000/activities