Blueprint Architecture Overview¶

How your Flask application stays modular and organised

What is a Blueprint?¶

A blueprint is a modular section of a Flask application.
Each blueprint contains its own:

• routes
• templates
• forms
• logic

This keeps your project clean, organised, and easy to extend.

Why use Blueprints?¶

Blueprints allow you to:

• separate different parts of your app
• avoid large, messy files
• reuse code across projects
• add or remove features easily
• keep your project scalable

This is the same pattern used in professional Flask applications.

The Blueprints in This Template¶

1. auth¶

Handles: - user registration
- login
- logout

Includes: - forms
- routes
- templates

2. main¶

Handles the core functionality of your project.

For the library example: - search
- add item
- view item

For other projects: - tasks
- products
- issues
- assets

3. pwa¶

Handles: - offline page
- manifest.json
- service worker registration

This makes your app installable and usable offline.

How Blueprints Are Registered¶

The application factory (src/app/__init__.py) registers each blueprint:

app.register_blueprint(auth_bp, url_prefix="/auth")
app.register_blueprint(main_bp)
app.register_blueprint(pwa_bp)

This tells Flask where each module lives.

Why this structure helps students¶

Students can:

• explore each module independently
• replace the main blueprint with their own project logic
• add new blueprints (e.g., admin, api, reports)
• understand how large applications are organised

This structure is intentionally designed to support both beginners and advanced learners.

• src/app/auth/
• src/app/main/
• src/app/pwa/