djust 0.2.2rc4

Blazing fast reactive server-side rendering for Django, powered by Rust

🚀 djust

Blazing fast reactive server-side rendering for Django, powered by Rust

djust brings Phoenix LiveView-style reactive components to Django, with performance that feels native. Write server-side Python code with automatic, instant client updates—no JavaScript bundling, no build step, no complexity.

🌐 djust.org | 🚀 Quick Start | 📝 Examples

✨ Features

• ⚡ 10-100x Faster - Rust-powered template engine and Virtual DOM diffing
• 🔄 Reactive Components - Phoenix LiveView-style server-side reactivity
• 🔌 Django Compatible - Works with existing Django templates and components
• 📦 Zero Build Step - Just ~5KB of client JavaScript, no bundling needed
• 🌐 WebSocket Updates - Real-time DOM patches over WebSocket (with HTTP fallback)
• 🎯 Minimal Client Code - Smart diffing sends only what changed
• 🔒 Type Safe - Rust guarantees for core performance-critical code
• 🐞 Developer Debug Panel - Interactive debugging with event history and VDOM inspection
• 💤 Lazy Hydration - Defer WebSocket connections for below-fold content (20-40% memory savings)
• 🚀 TurboNav Compatible - Works seamlessly with Turbo-style client-side navigation

🎯 Quick Example

from djust import LiveView

class CounterView(LiveView):
    template_string = """
    <div>
        <h1>Count: {{ count }}</h1>
        <button dj-click="increment">+</button>
        <button dj-click="decrement">-</button>
    </div>
    """

    def mount(self, request, **kwargs):
        self.count = 0

    def increment(self):
        self.count += 1  # Automatically updates client!

    def decrement(self):
        self.count -= 1

That's it! No JavaScript needed. State changes automatically trigger minimal DOM updates.

📊 Performance

Benchmarked on M1 MacBook Pro (2021):

Operation	Django	djust	Speedup
Template Rendering (100 items)	2.5 ms	0.15 ms	16.7x
Large List (10k items)	450 ms	12 ms	37.5x
Virtual DOM Diff	N/A	0.08 ms	Sub-ms
Round-trip Update	50 ms	5 ms	10x

Run benchmarks yourself:

cd benchmarks
python benchmark.py

🚀 Installation

Prerequisites

• Python 3.8+
• Rust 1.70+ (for building from source)
• Django 3.2+

Install from PyPI (when published)

pip install djust

Build from Source

Using Make (Easiest - Recommended for Development)

# Clone the repository
git clone https://github.com/djust-org/djust.git
cd djust

# Install Rust (if needed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Install everything and build
make install

# Start the development server
make start

# See all available commands
make help

Common Make Commands:

• make start - Start development server with hot reload
• make stop - Stop the development server
• make status - Check if server is running
• make test - Run all tests
• make clean - Clean build artifacts
• make help - Show all available commands

Using uv (Fast)

# Clone the repository
git clone https://github.com/djust-org/djust.git
cd djust

# Install Rust (if needed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Install uv (if needed)
curl -LsSf https://astral.sh/uv/install.sh | sh

# Create virtual environment and install dependencies
uv venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate

# Install maturin and build
uv pip install maturin
maturin develop --release

Using pip

# Clone the repository
git clone https://github.com/djust-org/djust.git
cd djust

# Install Rust (if needed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Create virtual environment
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install maturin
pip install maturin

# Build and install
maturin develop --release

# Or build wheel
maturin build --release
pip install target/wheels/djust-*.whl

📖 Documentation

Setup

1. Add to INSTALLED_APPS:

INSTALLED_APPS = [
    # ...
    'channels',  # Required for WebSocket support
    'djust',
    # ...
]

2. Configure ASGI application (asgi.py):

import os
from django.core.asgi import get_asgi_application
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.auth import AuthMiddlewareStack
from djust.websocket import LiveViewConsumer
from django.urls import path

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myproject.settings')

application = ProtocolTypeRouter({
    "http": get_asgi_application(),
    "websocket": AuthMiddlewareStack(
        URLRouter([
            path('ws/live/', LiveViewConsumer.as_asgi()),
        ])
    ),
})

3. Add to settings.py:

ASGI_APPLICATION = 'myproject.asgi.application'

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels.layers.InMemoryChannelLayer'
    }
}

Creating LiveViews

Class-Based LiveView

from djust import LiveView

class TodoListView(LiveView):
    template_name = 'todos.html'  # Or use template_string

    def mount(self, request, **kwargs):
        """Called when view is first loaded"""
        self.todos = []

    def add_todo(self, text):
        """Event handler - called from client"""
        self.todos.append({'text': text, 'done': False})

    def toggle_todo(self, index):
        self.todos[index]['done'] = not self.todos[index]['done']

Function-Based LiveView

from djust import live_view

@live_view(template_name='counter.html')
def counter_view(request):
    count = 0

    def increment():
        nonlocal count
        count += 1

    return locals()  # Returns all local variables as context

Template Syntax

djust supports Django template syntax with event binding:

<!-- Variables -->
<h1>{{ title }}</h1>

<!-- Filters -->
<p>{{ text|upper }}</p>
<a href="?q={{ query|urlencode }}">Search</a>

<!-- Control flow -->
{% if show %}
    <div>Visible</div>
{% endif %}

{% if count > 10 %}
    <div>Many items!</div>
{% endif %}

{% for item in items %}
    <li>{{ item }}</li>
{% endfor %}

<!-- URL resolution -->
<a href="{% url 'myapp:detail' pk=item.id %}">View</a>

<!-- Template includes -->
{% include "partials/header.html" %}

<!-- Event binding -->
<button dj-click="increment">Click me</button>
<input dj-input="on_search" type="text" />
<form dj-submit="submit_form">
    <input name="email" />
    <button type="submit">Submit</button>
</form>

Supported Events

• dj-click - Click events
• dj-input - Input events (passes value)
• dj-change - Change events (passes value)
• dj-submit - Form submission (passes form data as dict)

Reusable Components

djust provides a powerful component system with automatic state management and stable component IDs.

Basic Component Example

from djust.components import AlertComponent

class MyView(LiveView):
    def mount(self, request):
        # Components get automatic IDs based on attribute names
        self.alert_success = AlertComponent(
            message="Operation successful!",
            type="success",
            dismissible=True
        )
        # component_id automatically becomes "alert_success"

Component ID Management

Components automatically receive a stable component_id based on their attribute name in your view. This eliminates manual ID management:

# When you write:
self.alert_success = AlertComponent(message="Success!")

# The framework automatically:
# 1. Sets component.component_id = "alert_success"
# 2. Persists this ID across renders and events
# 3. Uses it in HTML: data-component-id="alert_success"
# 4. Routes events back to the correct component

Why it works:

• The attribute name (alert_success) is already unique within your view
• It's stable across re-renders and WebSocket reconnections
• Event handlers can reference components by their attribute names
• No manual ID strings to keep in sync

Event Routing Example:

class MyView(LiveView):
    def mount(self, request):
        self.alert_warning = AlertComponent(
            message="Warning message",
            dismissible=True
        )

    def dismiss(self, component_id: str = None):
        """Handle dismissal - automatically routes to correct component"""
        if component_id and hasattr(self, component_id):
            component = getattr(self, component_id)
            if hasattr(component, 'dismiss'):
                component.dismiss()  # component_id="alert_warning"

When the dismiss button is clicked, the client sends component_id="alert_warning", and the handler uses getattr(self, "alert_warning") to find the component.

Creating Custom Components

from djust import Component, register_component

@register_component('my-button')
class Button(Component):
    template = '<button dj-click="on_click">{{ label }}</button>'

    def __init__(self, label="Click"):
        super().__init__()
        self.label = label
        self.clicks = 0

    def on_click(self):
        self.clicks += 1
        print(f"Clicked {self.clicks} times!")

Decorators

from djust import LiveView, event_handler, reactive

class MyView(LiveView):
    @event_handler
    def handle_click(self):
        """Marks method as event handler"""
        pass

    @reactive
    def count(self):
        """Reactive property - auto-triggers updates"""
        return self._count

    @count.setter
    def count(self, value):
        self._count = value

Configuration

Configure djust in your Django settings.py:

LIVEVIEW_CONFIG = {
    # Transport mode
    'use_websocket': True,  # Set to False for HTTP-only mode (no WebSocket dependency)

    # Debug settings
    'debug_vdom': False,  # Enable detailed VDOM patch logging (for troubleshooting)

    # CSS Framework
    'css_framework': 'bootstrap5',  # Options: 'bootstrap5', 'tailwind', None
}

Common Configuration Options:

Option	Default	Description
use_websocket	True	Use WebSocket transport (requires Django Channels)
debug_vdom	False	Enable detailed VDOM debugging logs
css_framework	'bootstrap5'	CSS framework for components

Debug Mode:

When troubleshooting VDOM issues, enable debug logging:

# In settings.py
LIVEVIEW_CONFIG = {
    'debug_vdom': True,
}

# Or programmatically
from djust.config import config
config.set('debug_vdom', True)

This will log:

• Server-side: Patch generation details (stderr)
• Client-side: Patch application and DOM traversal (browser console)

State Management

djust provides Python-only state management decorators that eliminate the need for manual JavaScript.

🚀 Quick Start (5 minutes)

Build a debounced search in 8 lines of Python (no JavaScript):

from djust import LiveView
from djust.decorators import debounce

class ProductSearchView(LiveView):
    template_string = """
    <input dj-input="search" placeholder="Search products..." />
    <div>{% for p in results %}<div>{{ p.name }}</div>{% endfor %}</div>
    """

    def mount(self, request):
        self.results = []

    @debounce(wait=0.5)  # Wait 500ms after typing stops
    def search(self, query: str = "", **kwargs):
        self.results = Product.objects.filter(name__icontains=query)[:10]

That's it! Server only queries after you stop typing. Add @optimistic for instant UI updates, @cache(ttl=300) to cache responses for 5 minutes.

👉 Full Quick Start Guide (5 min)

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Key Features

• ✅ Zero JavaScript Required - Common patterns work without writing any JS
• ✅ 87% Code Reduction - Decorators replace hundreds of lines of manual JavaScript
• ✅ Smallest Bundle - 7.1 KB client.js (vs Phoenix ~30KB, Livewire ~50KB)
• ✅ Competitive DX - Matches Phoenix LiveView and Laravel Livewire developer experience

Available Decorators

Decorator	Use When	Example
@debounce(wait)	User is typing	Search, autosave
@throttle(interval)	Rapid events	Scroll, resize
@optimistic	Instant feedback	Counter, toggle
@cache(ttl, key_params)	Repeated queries	Autocomplete
@client_state(keys)	Multi-component	Dashboard filters
DraftModeMixin	Auto-save forms	Contact form

Quick Decision Matrix:

• Typing in input? → @debounce(0.5)
• Scrolling/resizing? → @throttle(0.1)
• Need instant UI update? → @optimistic
• Same query multiple times? → @cache(ttl)
• Multiple components? → @client_state([keys])
• Auto-save forms? → DraftModeMixin

Learn More

• 🚀 Quick Start (5 min) - Get productive fast
• 📚 Full Tutorial (20 min) - Step-by-step Product Search
• 📖 API Reference - Complete decorator docs + cheat sheet
• 🎯 Examples - Copy-paste ready code
• 🔄 Migration Guide - Convert JavaScript to Python
• ⚖️ Framework Comparison - vs Phoenix LiveView & Laravel Livewire

Developer Tooling

Debug Panel

Interactive debugging tool for LiveView development (DEBUG mode only):

# In settings.py
DEBUG = True  # Debug panel automatically enabled

Open: Press Ctrl+Shift+D (Windows/Linux) or Cmd+Shift+D (Mac), or click the 🐞 floating button

Features:

• 🔍 Event Handlers - Discover all handlers with parameters, types, and descriptions
• 📊 Event History - Real-time log with timing metrics (e.g., search • 45.2ms)
• ⚡ VDOM Patches - Monitor DOM updates with sub-millisecond precision
• 🔬 Variables - Inspect current view state

Learn More:

• 📖 Debug Panel Guide - Complete user guide
• 📝 Event Handler Best Practices - Patterns and conventions

Event Handlers

Always use @event_handler decorator for auto-discovery and validation:

from djust.decorators import event_handler

@event_handler()
def search(self, value: str = "", **kwargs):
    """Search handler - description shown in debug panel"""
    self.search_query = value

Parameter Convention: Use value for form inputs (dj-input, dj-change events):

# ✅ Correct - matches what form events send
@event_handler()
def search(self, value: str = "", **kwargs):
    self.search_query = value

# ❌ Wrong - won't receive input value
@event_handler()
def search(self, query: str = "", **kwargs):
    self.search_query = query  # Always "" (default)

🏗️ Architecture

┌─────────────────────────────────────────────┐
│  Browser                                    │
│  ├── Client.js (5KB) - Event & DOM patches │
│  └── WebSocket Connection                   │
└─────────────────────────────────────────────┘
           ↕️ WebSocket (Binary/JSON)
┌─────────────────────────────────────────────┐
│  Django + Channels (Python)                 │
│  ├── LiveView Classes                       │
│  ├── Event Handlers                         │
│  └── State Management                       │
└─────────────────────────────────────────────┘
           ↕️ Python/Rust FFI (PyO3)
┌─────────────────────────────────────────────┐
│  Rust Core (Native Speed)                   │
│  ├── Template Engine (<1ms)                │
│  ├── Virtual DOM Diffing (<100μs)          │
│  ├── HTML Parser                            │
│  └── Binary Serialization (MessagePack)    │
└─────────────────────────────────────────────┘

🎨 Examples

See the examples/demo_project directory for complete working examples:

• Counter - Simple reactive counter
• Todo List - CRUD operations with lists
• Chat - Real-time messaging

Run the demo:

cd examples/demo_project
pip install -r requirements.txt
python manage.py migrate
python manage.py runserver

Visit http://localhost:8000

🔧 Development

Project Structure

djust/
├── crates/
│   ├── djust_core/      # Core types & utilities
│   ├── djust_templates/ # Template engine
│   ├── djust_vdom/      # Virtual DOM & diffing
│   └── djust_live/      # Main PyO3 bindings
├── python/
│   └── djust/      # Python package
│       ├── live_view.py       # LiveView base class
│       ├── component.py       # Component system
│       ├── websocket.py       # WebSocket consumer
│       └── static/
│           └── client.js      # Client runtime
├── examples/                  # Example projects
├── benchmarks/               # Performance benchmarks
└── tests/                    # Tests

Running Tests

# Rust tests
cargo test

# Python tests
pytest

# Integration tests
cd examples/demo_project
python manage.py test

Building Documentation

cargo doc --open

💰 Supporting djust

djust is open source (MIT licensed) and free forever. If you're using djust in production or want to support development:

• ⭐ Star this repo - Help others discover djust
• 💜 GitHub Sponsors - Monthly support from $5/month

Your support helps us maintain and improve djust for everyone!

🤝 Contributing

Contributions welcome! Please read CONTRIBUTING.md first.

Areas we'd love help with:

• Additional Django template filters/tags
• More example applications
• Performance optimizations
• Documentation improvements
• Browser compatibility testing

📝 Roadmap

• Template inheritance ({% extends %})
• {% url %} and {% include %} tags
• Comparison operators in {% if %} tags
• More Django template filters (urlencode)
• File upload handling
• Server-sent events (SSE) fallback
• React/Vue component compatibility
• TypeScript definitions
• Redis-backed session storage
• Horizontal scaling support

🔒 Security

• CSRF protection via Django middleware
• XSS protection via automatic template escaping
• WebSocket authentication via Django sessions
• Rate limiting support

Report security issues to: [e-mail]

📄 License

MIT License - see LICENSE file for details.

🙏 Acknowledgments

• Inspired by Phoenix LiveView
• Built with PyO3 for Python/Rust interop
• Uses html5ever for HTML parsing
• Powered by the amazing Rust and Django communities

💬 Community & Support

• 🌐 djust.org - Official website
• 🚀 Quick Start - Get started in minutes
• 📝 Examples - Live code examples
• 🐛 Issues - Bug reports & feature requests
• 📧 Email: [e-mail]

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djust.org — Made with ❤️ by the djust community