django-pwa

This Django app turns your project into a progressive web app. Navigating to your site on an Android phone will prompt you to add the app to your home screen.

Launching the app from your home screen will display your app without browser chrome. As such, it's critical that your application provides all navigation within the HTML (no reliance on the browser back or forward button).

Requirements

Progressive Web Apps require HTTPS unless being served from localhost. If you're not already using HTTPS on your site, check out Let's Encrypt and ZeroSSL.

Installation

Install from PyPI:

pip install django-pwa

Configuration

Add pwa to your list of INSTALLED_APPS in settings.py:

INSTALLED_APPS = [
    ...
    'pwa',
    ...
]

Define STATICFILES_DIRS for your custom PWA_APP_ICONS

STATICFILES_DIRS = [
    os.path.join(BASE_DIR, 'static'),
]

Configure your app name, description, icons and splash screen images in settings.py:

PWA_APP_NAME = 'My App'
PWA_APP_DESCRIPTION = "My app description"
PWA_APP_THEME_COLOR = '#0A0302'
PWA_APP_BACKGROUND_COLOR = '#ffffff'
PWA_APP_DISPLAY = 'standalone'
PWA_APP_SCOPE = '/'
PWA_APP_ORIENTATION = 'any'
PWA_APP_START_URL = '/'
PWA_APP_STATUS_BAR_COLOR = 'default'
PWA_APP_ICONS = [
    {
        'src': '/static/images/my_app_icon.png',
        'sizes': '160x160'
    }
]
PWA_APP_ICONS_APPLE = [
    {
        'src': '/static/images/my_apple_icon.png',
        'sizes': '160x160'
    }
]
PWA_APP_SPLASH_SCREEN = [
    {
        'src': '/static/images/icons/splash-640x1136.png',
        'media': '(device-width: 320px) and (device-height: 568px) and (-webkit-device-pixel-ratio: 2)'
    }
]
PWA_APP_DIR = 'ltr'
PWA_APP_LANG = 'en-US'

Show console.log

Set the PWA_APP_DEBUG_MODE = False to disable the the console.log on browser.

All settings are optional, and the app will work fine with its internal defaults. Highly recommend setting at least PWA_APP_NAME, PWA_APP_DESCRIPTION, PWA_APP_ICONS and PWA_APP_SPLASH_SCREEN.

Add the progressive web app URLs to urls.py:

from django.urls import url, include

urlpatterns = [
    ...
    url('', include('pwa.urls')),  # You MUST use an empty string as the URL prefix
    ...
]

Inject the required meta tags in your base.html (or wherever your HTML <head> is defined):

{% load pwa %}

<head>
    ...
    {% progressive_web_app_meta %}
    ...
</head>

Troubleshooting

While running the Django test server:

Verify that /manifest.json is being served
Verify that /serviceworker.js is being served
Verify that /offline is being served
Use the Application tab in the Chrome Developer Tools to verify the progressive web app is configured correctly.
Use the "Add to homescreen" link on the Application Tab to verify you can add the app successfully.

The Service Worker

By default, the service worker implemented by this app is:

// Base Service Worker implementation.  To use your own Service Worker, set the PWA_SERVICE_WORKER_PATH variable in settings.py

var staticCacheName = "django-pwa-v" + new Date().getTime();
var filesToCache = [
    '/offline',
    '/css/django-pwa-app.css',
    '/images/icons/icon-72x72.png',
    '/images/icons/icon-96x96.png',
    '/images/icons/icon-128x128.png',
    '/images/icons/icon-144x144.png',
    '/images/icons/icon-152x152.png',
    '/images/icons/icon-192x192.png',
    '/images/icons/icon-384x384.png',
    '/images/icons/icon-512x512.png',
    '/static/images/icons/splash-640x1136.png',
    '/static/images/icons/splash-750x1334.png',
    '/static/images/icons/splash-1242x2208.png',
    '/static/images/icons/splash-1125x2436.png',
    '/static/images/icons/splash-828x1792.png',
    '/static/images/icons/splash-1242x2688.png',
    '/static/images/icons/splash-1536x2048.png',
    '/static/images/icons/splash-1668x2224.png',
    '/static/images/icons/splash-1668x2388.png',
    '/static/images/icons/splash-2048x2732.png'
];

// Cache on install
self.addEventListener("install", event => {
    this.skipWaiting();
    event.waitUntil(
        caches.open(staticCacheName)
            .then(cache => {
                return cache.addAll(filesToCache);
            })
    )
});

// Clear cache on activate
self.addEventListener('activate', event => {
    event.waitUntil(
        caches.keys().then(cacheNames => {
            return Promise.all(
                cacheNames
                    .filter(cacheName => (cacheName.startsWith("django-pwa-")))
                    .filter(cacheName => (cacheName !== staticCacheName))
                    .map(cacheName => caches.delete(cacheName))
            );
        })
    );
});

// Serve from Cache
self.addEventListener("fetch", event => {
    event.respondWith(
        caches.match(event.request)
            .then(response => {
                return response || fetch(event.request);
            })
            .catch(() => {
                return caches.match('offline');
            })
    )
});

Adding Your Own Service Worker

To add service worker functionality, you'll want to create a serviceworker.js or similarly named template in a template directory, and then point at it using the PWA_SERVICE_WORKER_PATH variable (PWA_APP_FETCH_URL is passed through).

PWA_SERVICE_WORKER_PATH = os.path.join(BASE_DIR, 'my_app', 'serviceworker.js')

The offline view

By default, the offline view is implemented in templates/offline.html You can overwrite it in a template directory if you continue using the default serviceworker.js.

Feedback

I welcome your feedback and pull requests. Enjoy!

License

All files in this repository are distributed under the MIT license.

GeorgeBacky/django-pwa