Django Blog with History Tracker

This is a simple Django-based blog application that includes a custom history tracking system. It is designed to be easily deployable on Render.

Features

• Blog Management: Create, edit, and delete blog posts.
• History Tracking: Automatically tracks changes (Creation, Saving, Deletion) to blog posts using Django signals.
• Deployment Ready: Pre-configured for Render.

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Project Structure & Configuration

• blog/: The main blog application containing models, views, and templates.
• history_tracker/: A dedicated app for tracking changes to models.
• mysite/: Project configuration directory (settings, URLs, WSGI/ASGI).
• manage.py: Django's command-line utility.
• requirements.txt: Python dependencies.
• render.yaml: Configuration for deployment on Render.
• build.sh: Build script used by Render for environment setup.

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Architecture Overview

System Diagram

The following diagram shows the high-level architecture of the application:

graph TD
    User((User)) --> WebServer[Web Server / Gunicorn]
    WebServer --> Django[Django Application]
    Django --> DB[(Database / SQLite or PostgreSQL)]
    Django --> Signals[Django Signals]
    Signals --> HistoryTracker[History Tracker App]
    HistoryTracker --> DB

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History Tracking Flow

The history_tracker uses Django's signal system to monitor changes in the Post model:

sequenceDiagram
    participant User
    participant PostModel as Post Model
    participant Signals
    participant Tracker as History Tracker
    participant DB

    User->>PostModel: Create/Update/Delete Post
    PostModel->>DB: Save Changes
    PostModel->>Signals: post_save / post_delete
    Signals->>Tracker: Trigger Signal Handler
    Tracker->>DB: Create Tracker Entry

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Deployment on Render

This project includes a render.yaml file for quick deployment:

1. Connect your GitHub repository to Render.
2. Render will automatically detect render.yaml and set up the Web Service and Database.
3. The build.sh script will:
   • Install dependencies.
   • Run collectstatic.
   • Apply migrations.
   • Create a default superuser (admin1 / admin123).

Note on Render Databases: The free tier PostgreSQL databases on Render.com expire after 30 days. Once the database expires, the Django application will no longer function properly as it won't be able to connect to the database.

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Live Demo on PythonAnywhere

A working version of this application is available at: https://zacniewski.pythonanywhere.com/

This demo is hosted on PythonAnywhere, which uses SQLite3 databases. Unlike the free tier on Render, these databases do not expire, ensuring the application remains functional over time.

For more information on how to deploy Django applications on PythonAnywhere, refer to the official documentation.

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Local Development

1. Clone the repository.
2. Install dependencies: pip install -r requirements.txt.
3. Run migrations: python manage.py migrate.
4. Start the server: python manage.py runserver.