Project Overview: Online
Shopping Cart
1. Project Objective
The Online Shopping Cart
is an e-commerce platform designed to allow users to browse products,
add them to their cart, and proceed to checkout with payment integration. The
platform also includes an admin panel for managing products, stock levels, and
processing orders. The system is developed using Python and Django,
providing a robust and scalable framework for web applications.
Scope of the Project: Online Shopping Cart
The Online Shopping
Cart project encompasses a broad range of features and functionalities,
catering to both customers and administrators, with future scalability in mind.
Below is a detailed breakdown of the scope of this project:
1. Functional Scope
1.1. Customer Features:
- Product
     Browsing:
 - View
      a catalog of products with details like name, description, price, and
      images.
 - Filter
      products by category, price range, or other criteria.
 - Search
      for specific products using a search bar.
 - Shopping
     Cart Management:
 - Add
      items to the cart directly from the product listing or details page.
 - Update
      item quantities or remove items from the cart.
 - Display
      cart totals dynamically as items are added or updated.
 - Order
     Placement:
 - Provide
      a streamlined checkout process.
 - Collect
      shipping and billing information from customers.
 - Support
      guest checkout without requiring user registration.
 - Payment
     Integration:
 - Integrate
      a secure payment gateway (e.g., Stripe or PayPal).
 - Process
      payments and provide real-time feedback (e.g., successful/failed
      transactions).
 - Support
      multiple payment methods like credit cards, debit cards, and wallets.
 - Order
     Confirmation and History:
 - Show
      an order confirmation page upon successful checkout.
 - Send
      email notifications for order confirmations (optional).
 - Allow
      logged-in users to view their order history.
 
1.2. Admin Features:
- Product
     Management:
 - Add,
      edit, and delete products.
 - Upload
      images for products and update descriptions and stock availability.
 - Assign
      products to categories for better organization.
 - Inventory
     Management:
 - Track
      product stock levels.
 - Receive
      alerts or notifications when stock is low (optional).
 - Order
     Management:
 - View
      and manage customer orders.
 - Update
      order statuses (e.g., pending, shipped, delivered).
 - Generate
      order invoices (optional).
 - User
     Management:
 - Manage
      registered customer accounts.
 - Provide
      role-based access control for admin users (e.g., super admin, staff).
 
2. Technical Scope
2.1. Frontend
Development:
- Use
     HTML, CSS, and Bootstrap to create a responsive and
     user-friendly interface.
 - Include
     JavaScript or libraries like jQuery for dynamic elements (e.g., cart
     updates).
 
2.2. Backend Development:
- Develop
     the backend with Django.
 - Use
     Django’s Model-View-Template (MVT) architecture for clean and
     maintainable code.
 - Implement
     authentication and authorization for customers and admins.
 
2.3. Database:
- Store
     product, customer, and order data in SQLite for development and PostgreSQL/MySQL
     for production.
 - Ensure
     efficient database queries with Django’s ORM.
 
2.4. Payment Gateway:
- Integrate
     a payment gateway (e.g., Stripe or Razorpay) for secure transactions.
 - Handle
     payment responses (success or failure) and update order statuses
     accordingly.
 
2.5. Hosting and
Deployment:
- Host
     the application on a cloud platform like Heroku, AWS, or DigitalOcean.
 - Set
     up a CI/CD pipeline for smoother deployments.
 
3. Non-Functional Scope
3.1. Security:
- Implement
     SSL/TLS for secure data transmission.
 - Use
     Django’s built-in security features to prevent SQL injection, XSS, and
     CSRF attacks.
 
3.2. Performance:
- Optimize
     database queries for faster load times.
 - Use
     caching mechanisms (e.g., Redis) for frequently accessed data like product
     listings.
 
3.3. Scalability:
- Design
     the application to support a growing number of users and products.
 - Use
     a scalable database and deploy on a platform that supports scaling (e.g.,
     AWS).
 
3.4. Usability:
- Ensure
     the interface is intuitive and accessible on both desktop and mobile
     devices.
 - Conduct
     user testing to refine the design.
 
3.5. Maintainability:
- Write
     modular and reusable code.
 - Use
     Git for version control and documentation for easier collaboration.
 
4. Future Scope
4.1. Advanced Features:
- Wishlist:
     Allow customers to save products for future purchases.
 - Product
     Reviews: Enable customers to leave feedback
     and ratings.
 - Coupons/Discounts:
     Support promotional codes for discounts.
 - Dynamic
     Pricing: Implement seasonal pricing or
     discounts.
 
4.2. Multi-Vendor
Support:
- Allow
     multiple sellers to manage their own products and sales.
 
4.3. Shipping and
Delivery Integration:
- Integrate
     with shipping APIs for live tracking of orders.
 - Provide
     estimated delivery times based on customer location.
 
4.4. Mobile App
Development:
- Create
     a mobile app version of the platform for Android and iOS.
 
5. Project Boundaries
- The
     initial project will focus on basic e-commerce functionalities.
 - Advanced
     features like multi-vendor support or shipping integration can be added
     incrementally.
 - Hosting
     and domain purchase are outside the development scope but can be
     recommended.
 
Features and Functionality of the Online Shopping Cart Project
The Online Shopping Cart project provides a comprehensive e-commerce solution with robust features for both customers and administrators.
1. Customer Features
1.1. Product Browsing
- Display
     products in a user-friendly grid or list format.
 - Show
     product details such as:
 - Name
 - Description
 - Price
 - Images
 - Stock
      availability
 - Enable
     category-based or filter-based navigation (e.g., price range, popularity).
 
1.2. Search Functionality
- Provide
     a search bar to find specific products by keywords or tags.
 
1.3. Shopping Cart
- Add
     products to the shopping cart.
 - Update
     product quantities in the cart dynamically.
 - Remove
     unwanted products from the cart.
 - Show
     a real-time total price calculation, including any applicable taxes.
 
1.4. User Authentication
- Allow
     users to:
 - Register
      for a new account.
 - Log
      in to their account.
 - Recover
      their password via email.
 - Support
     guest checkout for non-registered users.
 
1.5. Order Placement
- Provide
     a smooth checkout process with the following steps:
 - Collect
      billing and shipping information.
 - Review
      the cart summary and total amount before proceeding.
 - Apply
      promotional coupons or discounts (optional).
 
1.6. Payment Integration
- Secure
     payment processing using gateways like Stripe or PayPal.
 - Accept
     multiple payment methods, including:
 - Credit/Debit
      Cards
 - Digital
      Wallets
 - Provide
     real-time payment feedback (e.g., success or failure).
 
1.7. Order History
- Allow
     logged-in users to view past orders with details such as:
 - Products
      purchased
 - Order
      total
 - Payment
      status
 - Delivery
      status (pending, shipped, delivered).
 
1.8. Notifications and
Confirmation
- Send
     confirmation emails for successful orders.
 - Notify
     users about stock availability or order status updates.
 
2. Admin Features
2.1. Dashboard
- Provide
     an overview of:
 - Total
      sales
 - Pending
      and completed orders
 - Low-stock
      products
 
2.2. Product Management
- Add,
     update, and delete products.
 - Assign
     products to categories or collections.
 - Upload
     product images and manage descriptions.
 - Update
     stock levels dynamically.
 
2.3. Inventory Management
- Track
     inventory levels for all products.
 - Automatically
     update stock when a product is purchased.
 - Receive
     alerts for low-stock products.
 
2.4. Order Management
- View
     all customer orders with details such as:
 - Order
      ID
 - Customer
      information
 - Ordered
      products
 - Payment
      and delivery status
 - Update
     order statuses (e.g., pending, shipped, delivered).
 - Cancel
     or modify orders if necessary.
 
2.5. User Management
- View
     all registered users and their details.
 - Reset
     customer passwords or deactivate accounts if needed.
 - Assign
     roles (e.g., staff or super admin) for multi-tier management.
 
2.6. Reporting and
Analytics
- Generate
     reports for:
 - Sales
      performance
 - Popular
      products
 - Customer
      trends
 
3. Functional Highlights
3.1. Secure
Authentication
- Use
     Django’s built-in authentication for login/logout.
 - Implement
     hashed passwords for user accounts.
 - Add
     CAPTCHA or email verification for enhanced security (optional).
 
3.2. Responsive Design
- Ensure
     the platform is accessible on:
 - Desktop
 - Tablets
 - Mobile
      devices
 
3.3. Real-Time Updates
- Use
     AJAX or JavaScript for dynamic cart updates without page reloads.
 - Notify
     users of stock changes in real-time.
 
3.4. Email Notifications
- Send
     transactional emails, such as:
 - Order
      confirmations
 - Password
      recovery instructions
 - Shipping
      updates
 
3.5. Scalability
- Built-in
     support for additional features like:
 - Wishlists
 - Product
      reviews and ratings
 - Multi-vendor
      support
 
3.6. Payment Security
- Use
     SSL/TLS to encrypt payment data.
 - Comply
     with PCI DSS standards for payment processing.
 
4. Advanced Features for
Future Enhancements
- Wishlist
     Functionality: Allow users to save products for
     future purchases.
 - Discounts
     and Promotions: Add support for discount codes and
     seasonal promotions.
 - Delivery
     Tracking: Integrate APIs for real-time
     delivery status.
 - Product
     Reviews: Enable customers to leave feedback
     and rate products.
 - Multi-Language
     Support: Allow users to browse the platform
     in their preferred language.
 
Technologies Used in the Online Shopping Cart Project
The Online Shopping
Cart project employs a variety of technologies to build a robust, scalable,
and user-friendly e-commerce platform. The technologies used are divided into
the following categories:
1. Backend Technologies
1.1. Python
- The
     core programming language for this project.
 - Offers
     simplicity and extensive libraries for building web applications.
 - Enables
     clean and readable code for both logic and algorithms.
 
1.2. Django Framework
- Primary
     web framework for the backend.
 - Uses
     the Model-View-Template (MVT) architectural pattern, making
     development faster and more organized.
 - Features
     include:
 - Built-in
      user authentication system.
 - ORM
      (Object-Relational Mapping) for database operations.
 - Security
      features (e.g., CSRF protection, XSS prevention, SQL injection
      mitigation).
 
1.3. Django REST
Framework (Optional for API Integration)
- Extends
     Django's capabilities to create APIs for advanced features like:
 - Mobile
      app integration.
 - Third-party
      service interaction.
 
1.4.
SQLite/PostgreSQL/MySQL
- SQLite:
     Used as the default database during development for simplicity.
 - PostgreSQL/MySQL:
     Preferred in production for performance and scalability.
 - Stores
     data such as:
 - Product
      details
 - Customer
      information
 - Order
      transactions
 
2. Frontend Technologies
2.1. HTML
- Structures
     the web pages with semantic elements.
 - Ensures
     that content is logically organized and accessible.
 
2.2. CSS
- Styles
     the application for an appealing and professional look.
 - Implements
     responsive design for a seamless user experience on different devices.
 
2.3. Bootstrap
- A
     popular CSS framework used to build responsive and mobile-first designs
     quickly.
 - Includes
     pre-designed components like:
 - Navbars
 - Buttons
 - Cards
      for product displays.
 
2.4. JavaScript
- Adds
     interactivity to the application.
 - Manages
     dynamic features like:
 - Real-time
      cart updates.
 - Alerts
      for stock or payment status.
 
2.5. jQuery (Optional)
- Simplifies
     DOM manipulation and AJAX calls for asynchronous communication between
     frontend and backend.
 
3. Payment Integration
Technology
3.1. Payment Gateway APIs
- Integrate
     secure payment gateways such as:
 - Stripe
 - PayPal
 - Features
     include:
 - Tokenized
      payments.
 - Real-time
      payment status feedback.
 
3.2. SSL/TLS
- Encrypts
     communication between the client and server for secure payment processing.
 
4. Deployment and Hosting
4.1. Web Server
- Gunicorn:
     A Python WSGI HTTP Server for running Django applications in production.
 - Nginx:
     Used as a reverse proxy server to manage requests and serve static files
     efficiently.
 
4.2. Hosting Platform
- Heroku:
     Ideal for hosting small to medium-scale Django applications.
 - AWS/Google
     Cloud/DigitalOcean: Recommended for scalable hosting
     with advanced infrastructure.
 
4.3. Containerization
(Optional)
- Docker:
     Packages the application into containers for easier deployment and
     consistent development environments.
 
5. Version Control and
Collaboration
5.1. Git
- Tracks
     changes in the project codebase.
 - Supports
     branching and merging for feature development.
 
5.2. GitHub/GitLab
- Hosts
     the project repository.
 - Facilitates
     team collaboration and code reviews.
 
6. Additional Tools and
Libraries
6.1. Django Allauth
(Optional)
- Adds
     social login features (e.g., Google, Facebook).
 
6.2. Celery and Redis
(Optional)
- Manages
     asynchronous tasks such as:
 - Sending
      order confirmation emails.
 - Processing
      large data imports.
 
6.3. Django Storages
- Handles
     media storage on cloud services (e.g., AWS S3 for product images).
 
6.4. Cron Jobs (Optional)
- Automates
     repetitive tasks like:
 - Database
      backups.
 - Stock
      level alerts.
 
7. Security Technologies
7.1. Django Security
Features
- CSRF
     Tokens: Protect against cross-site request
     forgery.
 - Password
     Hashing: Secures user passwords using hashed
     storage.
 
7.2. HTTPS
- Enforces
     secure communication between users and the server.
 
7.3. Django Signals
- Tracks
     and logs critical actions like:
 - User
      login/logout.
 - Payment
      completion.
 
8. Scalability and
Performance Optimization
8.1. Caching
- Redis
     or Memcached: Speeds up frequently accessed data
     like product listings.
 
8.2. Content Delivery
Network (CDN)
- Delivers
     static assets (CSS, JS, images) quickly across the globe.
 - Popular
     options: Cloudflare, AWS CloudFront.
 
8.3. Load Balancers
- Distributes
     incoming requests across multiple servers for better performance.
 
9. Future Expansion
Technologies
9.1. API Development
- GraphQL:
     Enables fetching specific data for advanced features.
 - RESTful
     APIs: Provides integration with mobile apps or
     external services.
 
9.2. Machine Learning
(Optional)
- Personalizes
     product recommendations.
 - Analyzes
     user behavior for targeted marketing.
 
ER Diagram of the Online Shopping Cart Project
The Entity-Relationship (ER) Diagram represents the structure and relationships of the entities in the Online Shopping Cart Project. It is essential for database design and forms the backbone of the application.
1. Entities and
Attributes
1.1. User
Represents the customers
and administrators of the platform.
- Attributes:
 - user_id
      (Primary Key): Unique identifier for each user.
 - name:
      Full name of the user.
 - email:
      Email address used for login.
 - password:
      Encrypted password for authentication.
 - role:
      Specifies if the user is a customer or admin.
 - created_at:
      Timestamp for account creation.
 - updated_at:
      Timestamp for the last account update.
 
1.2. Product
Represents the items
available for purchase.
- Attributes:
 - product_id
      (Primary Key): Unique identifier for each product.
 - name:
      Name of the product.
 - description:
      Detailed description of the product.
 - price:
      Price of the product.
 - stock:
      Quantity of the product available in inventory.
 - category_id
      (Foreign Key): Links the product to its category.
 - created_at:
      Timestamp for when the product was added.
 - updated_at:
      Timestamp for the last update to the product.
 
1.3. Category
Represents the categories
to which products belong.
- Attributes:
 - category_id
      (Primary Key): Unique identifier for each category.
 - name:
      Name of the category.
 - description:
      Brief description of the category.
 - created_at:
      Timestamp for when the category was created.
 - updated_at:
      Timestamp for the last update to the category.
 
1.4. Cart
Represents the shopping
cart for a user.
- Attributes:
 - cart_id
      (Primary Key): Unique identifier for each cart.
 - user_id
      (Foreign Key): Links the cart to a specific user.
 - created_at:
      Timestamp for when the cart was created.
 - updated_at:
      Timestamp for the last update to the cart.
 
1.5. Cart_Item
Represents the products
added to a shopping cart.
- Attributes:
 - cart_item_id
      (Primary Key): Unique identifier for each cart item.
 - cart_id
      (Foreign Key): Links the item to a specific cart.
 - product_id
      (Foreign Key): Links the item to a specific product.
 - quantity:
      Quantity of the product in the cart.
 - subtotal:
      Price for the product quantity (price × quantity).
 
1.6. Order
Represents orders placed
by users.
- Attributes:
 - order_id
      (Primary Key): Unique identifier for each order.
 - user_id
      (Foreign Key): Links the order to the user who placed it.
 - total_price:
      Total price for all products in the order.
 - status:
      Status of the order (e.g., pending, shipped, delivered).
 - created_at:
      Timestamp for when the order was placed.
 - updated_at:
      Timestamp for the last update to the order.
 
1.7. Order_Item
Represents the products
included in an order.
- Attributes:
 - order_item_id
      (Primary Key): Unique identifier for each order item.
 - order_id
      (Foreign Key): Links the item to a specific order.
 - product_id
      (Foreign Key): Links the item to a specific product.
 - quantity:
      Quantity of the product in the order.
 - price:
      Price of the product at the time of purchase.
 - subtotal:
      Price for the product quantity (price × quantity).
 
1.8. Payment
Represents payment
details for an order.
- Attributes:
 - payment_id
      (Primary Key): Unique identifier for each payment.
 - order_id
      (Foreign Key): Links the payment to a specific order.
 - payment_method:
      Method used for the payment (e.g., Stripe, PayPal).
 - status:
      Status of the payment (e.g., success, failed).
 - transaction_id:
      Unique transaction identifier from the payment gateway.
 - paid_at:
      Timestamp for when the payment was completed.
 
2. Relationships
1.  
User ↔ Cart
o    Relationship:
One user can have one active cart.
o    Type:
One-to-One (user_id in the Cart table).
2.  
Cart ↔ Cart_Item
o    Relationship:
One cart can have multiple cart items.
o    Type:
One-to-Many (cart_id in the Cart_Item table).
3.  
Product ↔ Cart_Item
o    Relationship:
One product can be added to multiple cart items.
o    Type:
One-to-Many (product_id in the Cart_Item table).
4.  
User ↔ Order
o    Relationship:
One user can place multiple orders.
o    Type:
One-to-Many (user_id in the Order table).
5.  
Order ↔ Order_Item
o    Relationship:
One order can have multiple order items.
o    Type:
One-to-Many (order_id in the Order_Item table).
6.  
Product ↔ Order_Item
o    Relationship:
One product can be part of multiple orders.
o    Type:
One-to-Many (product_id in the Order_Item table).
7.  
Order ↔ Payment
o    Relationship:
One order can have one payment.
o    Type:
One-to-One (order_id in the Payment table).
8.  
Product ↔ Category
o    Relationship:
One category can have multiple products.
o    Type:
One-to-Many (category_id in the Product table).
3. Diagram Description
The ER Diagram consists
of rectangular boxes (entities) connected by lines (relationships). The
relationships are labeled to specify the connection type (one-to-one,
one-to-many). Each entity contains its attributes, with primary keys underlined
and foreign keys marked.
4. Key Points in Database
Design
1.  
Normalization:
o    The
database design ensures no data redundancy by breaking down data into smaller,
related tables.
o    Relationships
maintain the integrity of the database.
2.  
Indexes:
o    Indexing
primary and foreign keys ensures faster queries for frequently accessed data
like products and orders.
3.  
Scalability:
o    The
design can easily accommodate additional features like wishlists or product
reviews without major modifications.
Data Flow Diagram (DFD) for Online Shopping Cart Project
A Data Flow Diagram
(DFD) visually represents the flow of data within the system. It shows how
data is input, processed, stored, and output, giving a clear picture of the
system's functionality. The DFD for this Online Shopping Cart project
can be divided into multiple levels, with Level 0 (Context Diagram)
being the highest level, and Level 1 and Level 2 providing more
detail.
1. Level 0 DFD (Context
Diagram)
This level represents the
entire system as a single process interacting with external entities. It gives
a high-level view of how the system interacts with external users or systems.
Here, we only represent the major entities and their interactions with the
shopping platform.
Entities:
1.  
User/Customer:
Interacts with the online shopping platform for browsing products, adding them
to the cart, and placing orders.
2.  
Admin:
Manages products, categories, and views order details.
3.  
Payment Gateway:
Handles payments for the orders.
Data Stores:
1.  
Product Database:
Stores information about products, categories, and their details.
2.  
User Database:
Stores user details, including customer and admin accounts.
3.  
Order Database:
Stores order details, statuses, and payment information.
DFD Process:
- Online
     Shopping Cart System: The main process that
     interacts with the external entities and manages the internal flow of
     data. It receives data from users for order creation and interacts with
     the payment gateway for processing payments.
 
Level 0 DFD:
+--------------------------+
          |        User/Customer      |
          +--------------------------+
                |    (Browse Products, Order)
                |
                v
+-------------------------------------------+
|      Online Shopping Cart System         |
|                                           |
|   - Browse products                       |
|   - Add products to cart                  |
|   - Place orders                          |
|   - Process payment                       |
+-------------------------------------------+
                |
                |  (Payment, Order Details)
                v
          +---------------------+
          |   
Payment Gateway   |
          +---------------------+
                |
                v
      +--------------------------+
      |  
Product Database       |
      +--------------------------+
      |  
User Database          |
      +--------------------------+
      |  
Order Database         |
      +--------------------------+
2. Level 1 DFD
(Decomposition of Main System)
In Level 1, the
main process (Online Shopping Cart System) is decomposed into more detailed
sub-processes. Here, we explore key functions like Product Management, Cart
Management, Order Management, and Payment Processing.
Sub-processes in the
Online Shopping Cart System:
1.  
Product Management:
Responsible for fetching products from the database and displaying them to the
users.
2.  
Cart Management:
Handles adding/removing products to/from the cart and calculating the total
price.
3.  
Order Management:
Creates orders, stores them in the order database, and updates their status.
4.  
Payment Processing:
Handles payment transactions via the payment gateway and updates the payment
status.
DFD Process:
+-------------------------+
           |      User/Customer      |
           +-------------------------+
                     |
                     | (Browse Products)
                     v
  
+--------------------------------------------+
   |   
Product Management                   
|
   |    -
Fetch products from database        |
   |    -
Display products to users           |
  
+--------------------------------------------+
                     |
                     v
    +-------------------------------+    +-------------------------------+
    |  
Cart Management             
|    |   Order Management            |
    |   -
Add/Remove Products        |    |   -
Create Order              |
    |   -
Calculate Total Price      |    |   -
Store Order in Database   |
    +-------------------------------+    +-------------------------------+
                     |                           |
                     v                           v
           +-----------------------------+   +--------------------------+
           |  
Payment Processing        |   |  
Product Database       |
           |  
- Process Payment         |   |   -
Product Info         |
           |  
- Update Payment Status   |   |   -
Category Info        |
           +-----------------------------+   +--------------------------+
                     |
                     v
           +--------------------------+
           | 
User Database           |
           +--------------------------+
                     |
                     v
           +--------------------------+
           | 
Order Database          |
           +--------------------------+
3. Level 2 DFD (Detailed
Decomposition of Sub-processes)
At Level 2, the
sub-processes from Level 1 are broken down into even more detailed
steps, showing the internal workings of each sub-process.
1. Product Management
This process involves
fetching and displaying products to users.
- Fetch
     Product Details: Retrieves the list of available products
     from the database.
 - Display
     Products: Displays the products and their
     details (e.g., name, price, description).
 
+----------------------------+
    |   
Fetch Product Details   |
    +----------------------------+
             |
             v
    +----------------------------+
    |  
Display Products         |
    +----------------------------+
2. Cart Management
This process manages
products in the user's cart.
- Add
     Product to Cart: Adds selected products to the cart.
 - Remove
     Product from Cart: Removes products from the
     cart.
 - Calculate
     Total Price: Computes the total price of
     products in the cart, including any taxes and discounts.
 
+----------------------------+
    | Add Product to Cart        |
    +----------------------------+
             |
             v
    +----------------------------+
    | Remove Product from Cart   |
    +----------------------------+
             |
             v
    +----------------------------+
    | Calculate Total Price      |
    +----------------------------+
3. Order Management
This process handles
order creation and updates.
- Create
     Order: The system generates an order once the user
     proceeds to checkout.
 - Store
     Order in Database: Saves the order details into
     the order database.
 - Update
     Order Status: Updates the status of the order
     (e.g., "Pending", "Shipped").
 
+----------------------------+
    | Create Order               |
    +----------------------------+
             |
             v
    +----------------------------+
    | Store Order in Database    |
    +----------------------------+
             |
             v
    +----------------------------+
    | Update Order Status        |
    +----------------------------+
4. Payment Processing
This process deals with
handling payments.
- Process
     Payment: Sends the payment request to the
     payment gateway.
 - Update
     Payment Status: Updates the payment status based on
     the response from the payment gateway (e.g., "Success",
     "Failed").
 
+----------------------------+
    | Process Payment            |
    +----------------------------+
             |
             v
    +----------------------------+
    | Update Payment Status      |
    +----------------------------+
Summary of DFD:
1.  
Level 0 (Context Diagram):
The system is represented as a single process interacting with external
entities: the user, admin, and payment gateway. It shows a high-level flow of
data.
2.  
Level 1 (Decomposition):
The Online Shopping Cart System is broken down into sub-processes such as
Product Management, Cart Management, Order Management, and Payment Processing.
It also shows data flows between the user, system, and databases.
3.  
Level 2 (Detailed Decomposition):
Further details on each sub-process are provided, showing specific tasks like
adding/removing products, calculating prices, and processing payments.
This DFD offers a
comprehensive view of how data flows within the system, starting from the user
interactions all the way to the processing and storage of orders and payments.
Project Structure for Online Shopping Cart with Django
Below is the full project
structure for the Online Shopping Cart project using Django,
including all necessary files and directories for both the frontend (HTML, CSS,
JavaScript) and backend (Django models, views, URLs, templates).
online_shopping_cart_project/
│
├── online_shopping_cart/                 # Main Django project
directory
│   ├── __init__.py                       # Initializes the Django
app
│   ├── settings.py                       # Configuration for the
Django project
│   ├── urls.py                           # Main URL routing
for the project
│   ├── asgi.py                           # ASGI application
configuration
│   ├── wsgi.py                           # WSGI application
configuration
│   └── manage.py                         # Django management
script
│
├── cart/                                 # Django app
for shopping cart functionality
│   ├── __init__.py
│   ├── admin.py                          # Admin interface for
cart app
│   ├── apps.py                           # Configuration for
the cart app
│   ├── migrations/                       # Database migration
files
│   ├── models.py                         # Database models
(Product, Cart, Order, etc.)
│   ├── views.py                          # Views for
cart-related actions (add to cart, checkout)
│   ├── urls.py                           # URLs for cart app
(URL routing for cart)
│   ├── templates/                        # HTML templates for
the cart app
│   │  
└── cart/
│   │      
├── cart_detail.html          # Cart detail page
│   │      
├── checkout.html             # Checkout page
│   │      
├── product_list.html         # Product listing page
│   │      
└── order_confirmation.html   #
Order confirmation page
│   ├── static/                           # Static files (CSS,
JS)
│   │   ├── css/
│   │  
│   └── styles.css                # Main CSS file
│   │  
└── js/
│   │      
└── cart.js                   #
JavaScript for cart functionality (add/remove items)
│   └── __init__.py
│
├── products/                             # Django app for
product management
│   ├── __init__.py
│   ├── admin.py                          # Admin interface for
managing products
│   ├── apps.py                           # Configuration for
the products app
│   ├── migrations/                       # Database migrations
for products
│   ├── models.py                         # Database models for
products (e.g., Product, Category)
│   ├── views.py                          # Views for
displaying products, handling product search
│   ├── urls.py                           # URL routing for
the products app
│   ├── templates/                        # HTML templates for
products
│   │  
└── products/
│   │      
├──
product_detail.html       # Product
detail page
│   │      
└── product_list.html         #
Product listing page
│   └── __init__.py
│
├── users/                                # Django app
for user management (customer, admin)
│   ├── __init__.py
│   ├── admin.py                          # Admin interface for
managing users
│   ├── apps.py                           # Configuration for
the users app
│   ├── migrations/                       # Database migration
files
│   ├── models.py                         # User model (extends
Django User model)
│   ├── views.py                          # Views for
registration, login, and user profile
│   ├── urls.py                           # URL routing for
user-related pages (login, register)
│   ├── templates/                        # HTML templates for
user-related functionality
│   │  
└── users/
│   │      
├── login.html                # Login page
│   │      
├── register.html             # Registration page
│   │      
└── profile.html              #
User profile page
│   └── __init__.py
│
├── orders/                               # Django app for
handling orders
│   ├── __init__.py
│   ├── admin.py                          # Admin interface for
managing orders
│   ├── apps.py                           # Configuration for
the orders app
│   ├── migrations/                       # Database migration
files for orders
│   ├── models.py                         # Order models (Order,
OrderItem, Payment)
│   ├── views.py                          # Views for handling
order checkout, order history
│   ├── urls.py                           # URL routing for
order-related actions
│   ├── templates/                        # HTML templates for
orders
│   │  
└── orders/
│   │      
├──
order_history.html        # User's order
history page
│   │      
├── checkout.html             # Checkout page
│   │      
└── order_confirmation.html   #
Order confirmation page
│   └── __init__.py
│
├── static/                               # Static files
for the entire project (CSS, JS)
│   ├── images/
│   │  
└── logo.png                     
# Logo image
│   └── css/
│       └── main.css                      # Global CSS
│
├── media/                                # Directory for
uploaded files (e.g., product images)
│   └── products/
│       └── product_image.jpg              # Example product image
│
└── templates/                            # Global templates
for the entire project
    └── base.html                         # Base template for
the entire site (header, footer)
Explanation of the
Project Structure:
1.  
online_shopping_cart/:
o    This
is the root directory of the Django project containing the settings.py,
urls.py, and other project-level files. It also contains configuration files
for managing the Django project.
2.  
cart/:
o    This
app handles the core functionality of the shopping cart, including
adding/removing products, managing the cart, and checking out. It includes
views for the cart detail, checkout, and product list.
3.  
products/:
o    The
products app manages the products and categories. It allows admins to
add/edit/remove products, and customers can browse and search for products on
the frontend.
4.  
users/:
o    This
app handles user authentication, registration, and profile management. It also
includes views for login, logout, and user registration.
5.  
orders/:
o    This
app handles the creation of orders, the payment process, and viewing order
history. It manages the order process from checkout to confirmation and updates
the order status.
6.  
static/:
o    Contains
all static files (CSS, JavaScript, images) for the frontend part of the
website. Static files are served to users without dynamic processing.
7.  
media/:
o    This
directory stores user-uploaded files, such as product images, which can be
served dynamically.
8.  
templates/:
o    Contains
global templates like base.html, which is extended by other templates for
common layout elements like the header, footer, etc.
Key Points:
- Django
     Model-View-Template (MVT) Architecture: Each app
     (cart, products, users, orders) follows the MVT pattern, where models
     define the data structure, views handle user interactions, and templates
     provide the HTML structure.
 - Static
     and Media Files: Static files (CSS, JS) are for
     styling and functionality, whereas media files are for user-uploaded
     content like product images.
 - Database
     Migrations: Each app has its own migration
     files to handle database schema changes when models are updated.
 - Admin
     Interface: Django provides a built-in admin interface
     for managing products, users, and orders, accessible via the admin.py
     file.
 
This project structure
provides clear separation of concerns, making it modular and easy to manage. It
also ensures that the code remains scalable as new features are added, such as
user reviews, promotions, or advanced search functionalities.
How to setup the project: Click here
Code In Detail:Click Here
Know The details about the tables used here with table create code : Click Here



