django-push-notifications

A minimal Django app that implements Device models that can send messages through APNS, FCM/GCM and WNS.

The app implements three models: GCMDevice, APNSDevice and WNSDevice. Those models share the same attributes:

• name (optional): A name for the device.
• active (default True): A boolean that determines whether the device will be sent notifications.
• user (optional): A foreign key to auth.User, if you wish to link the device to a specific user.
• device_id (optional): A UUID for the device obtained from Android/iOS/Windows APIs, if you wish to uniquely identify it.
• registration_id (required): The FCM/GCM registration id or the APNS token for the device.

The app also implements an admin panel, through which you can test single and bulk notifications. Select one or more FCM/GCM, APNS or WNS devices and in the action dropdown, select "Send test message" or "Send test message in bulk", accordingly. Note that sending a non-bulk test message to more than one device will just iterate over the devices and send multiple single messages. UPDATE_ON_DUPLICATE_REG_ID: Transform create of an existing Device (based on registration id) into a update. See below Update of device with duplicate registration ID for more details.

Dependencies

• Python 2.7 or 3.4+
• Django 1.11+
• For the API module, Django REST Framework 3.7+ is required.
• For WebPush (WP), pywebpush 1.3.0+ is required. py-vapid 1.3.0+ is required for generating the WebPush private key; however this step does not need to occur on the application server.

Setup

You can install the library directly from pypi using pip:

$ pip install django-push-notifications

Edit your settings.py file:

INSTALLED_APPS = (
        ...
        "push_notifications"
)

PUSH_NOTIFICATIONS_SETTINGS = {
        "FCM_API_KEY": "[your api key]",
        "GCM_API_KEY": "[your api key]",
        "APNS_CERTIFICATE": "/path/to/your/certificate.pem",
        "APNS_TOPIC": "com.example.push_test",
        "WNS_PACKAGE_SECURITY_ID": "[your package security id, e.g: 'ms-app://e-3-4-6234...']",
        "WNS_SECRET_KEY": "[your app secret key, e.g.: 'KDiejnLKDUWodsjmewuSZkk']",
        "WP_PRIVATE_KEY": "/path/to/your/private.pem",
        "WP_CLAIMS": {'sub': "mailto: development@example.com"}
}

You can learn more about APNS certificates here.

Native Django migrations are in use. manage.py migrate will install and migrate all models.

Settings list

All settings are contained in a PUSH_NOTIFICATIONS_SETTINGS dict.

In order to use FCM/GCM, you are required to include FCM_API_KEY or GCM_API_KEY. For APNS, you are required to include APNS_CERTIFICATE. For WNS, you need both the WNS_PACKAGE_SECURITY_KEY and the WNS_SECRET_KEY.

General settings

• USER_MODEL: Your user model of choice. Eg. myapp.User. Defaults to settings.AUTH_USER_MODEL.
• UPDATE_ON_DUPLICATE_REG_ID: Transform create of an existing Device (based on registration id) into a update. See below Update of device with duplicate registration ID for more details.

APNS settings

• APNS_CERTIFICATE: Absolute path to your APNS certificate file. Certificates with passphrases are not supported.
• APNS_TOPIC: The topic of the remote notification, which is typically the bundle ID for your app. If you omit this header and your APNs certificate does not specify multiple topics, the APNs server uses the certificate’s Subject as the default topic.
• APNS_USE_ALTERNATIVE_PORT: Use port 2197 for APNS, instead of default port 443.
• APNS_USE_SANDBOX: Use 'api.development.push.apple.com', instead of default host 'api.push.apple.com'.

FCM/GCM settings

• FCM_API_KEY: Your API key for Firebase Cloud Messaging.
• FCM_POST_URL: The full url that FCM notifications will be POSTed to. Defaults to https://fcm.googleapis.com/fcm/send.
• FCM_MAX_RECIPIENTS: The maximum amount of recipients that can be contained per bulk message. If the registration_ids list is larger than that number, multiple bulk messages will be sent. Defaults to 1000 (the maximum amount supported by FCM).
• FCM_ERROR_TIMEOUT: The timeout on FCM POSTs.
• GCM_API_KEY, GCM_POST_URL, GCM_MAX_RECIPIENTS, GCM_ERROR_TIMEOUT: Same parameters for GCM

WNS settings

• WNS_PACKAGE_SECURITY_KEY: TODO
• WNS_SECRET_KEY: TODO

WP settings

• Install:

pip install pywebpush
pip install py-vapid  (Only for generating key)

• Getting keys:

  • Create file (claim.json) like this:

{
        "sub": "mailto: development@example.com",
        "aud": "https://android.googleapis.com"
}

- Generate public and private keys:

vapid --sign claim.json

No private_key.pem file found.
Do you want me to create one for you? (Y/n)Y
Do you want me to create one for you? (Y/n)Y
Generating private_key.pem
Generating public_key.pem
Include the following headers in your request:

Crypto-Key: p256ecdsa=BEFuGfKKEFp-kEBMxAIw7ng8HeH_QwnH5_h55ijKD4FRvgdJU1GVlDo8K5U5ak4cMZdQTUJlkA34llWF0xHya70

Authorization: WebPush eyJ0eXAiOiJKV1QiLCJhbGciOiJFUzI1NiJ9.eyJhdWQiOiJodHRwczovL2FuZHJvaWQuZ29vZ2xlYXBpcy5jb20iLCJleHAiOiIxNTA4NDkwODM2Iiwic3ViIjoibWFpbHRvOiBkZXZlbG9wbWVudEBleGFtcGxlLmNvbSJ9.r5CYMs86X3JZ4AEs76pXY5PxsnEhIFJ-0ckbibmFHZuyzfIpf1ZGIJbSI7knA4ufu7Hm8RFfEg5wWN1Yf-dR2A

- Generate client public key (applicationServerKey)

vapid --applicationServerKey

Application Server Key = BEFuGfKKEFp-kEBMxAIw7ng8HeH_QwnH5_h55ijKD4FRvgdJU1GVlDo8K5U5ak4cMZdQTUJlkA34llWF0xHya70

• Configure settings:
• WP_PRIVATE_KEY: Absolute path to your private certificate file: os.path.join(BASE_DIR, "private_key.pem")
• WP_CLAIMS: Dictionary with the same sub info like claims file: {'sub': "mailto: development@example.com"}
• WP_ERROR_TIMEOUT: The timeout on WebPush POSTs. (Optional)
• WP_POST_URL: A dictionary (key per browser supported) with the full url that webpush notifications will be POSTed to. (Optional)
• Configure client (javascript):

// Utils functions:

function urlBase64ToUint8Array (base64String) {
        var padding = '='.repeat((4 - base64String.length % 4) % 4)
        var base64 = (base64String + padding)
                .replace(/\-/g, '+')
                .replace(/_/g, '/')

        var rawData = window.atob(base64)
        var outputArray = new Uint8Array(rawData.length)

        for (var i = 0; i < rawData.length; ++i) {
                outputArray[i] = rawData.charCodeAt(i)
        }
        return outputArray;
}
function loadVersionBrowser (userAgent) {
        var ua = userAgent, tem, M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
        if (/trident/i.test(M[1])) {
                tem = /\brv[ :]+(\d+)/g.exec(ua) || [];
                return {name: 'IE', version: (tem[1] || '')};
        }
        if (M[1] === 'Chrome') {
                tem = ua.match(/\bOPR\/(\d+)/);
                if (tem != null) {
                        return {name: 'Opera', version: tem[1]};
                }
        }
        M = M[2] ? [M[1], M[2]] : [navigator.appName, navigator.appVersion, '-?'];
        if ((tem = ua.match(/version\/(\d+)/i)) != null) {
                M.splice(1, 1, tem[1]);
        }
        return {
                name: M[0],
                version: M[1]
        };
};
var applicationServerKey = "BEFuGfKKEFp-kEBMxAIw7ng8HeH_QwnH5_h55ijKD4FRvgdJU1GVlDo8K5U5ak4cMZdQTUJlkA34llWF0xHya70";
....

// In your ready listener
if ('serviceWorker' in navigator) {
        // The service worker has to store in the root of the app
        // http://stackoverflow.com/questions/29874068/navigator-serviceworker-is-never-ready
        var browser = loadVersionBrowser();
        navigator.serviceWorker.register('navigatorPush.service.js?version=1.0.0').then(function (reg) {
                reg.pushManager.subscribe({
                        userVisibleOnly: true,
                        applicationServerKey: urlBase64ToUint8Array(applicationServerKey)
                }).then(function (sub) {
                        var endpointParts = sub.endpoint.split('/');
                        var registration_id = endpointParts[endpointParts.length - 1];
                        var data = {
                                'browser': browser.name.toUpperCase(),
                                'p256dh': btoa(String.fromCharCode.apply(null, new Uint8Array(sub.getKey('p256dh')))),
                                'auth': btoa(String.fromCharCode.apply(null, new Uint8Array(sub.getKey('auth')))),
                                'name': 'XXXXX',
                                'registration_id': registration_id
                        };
                        requestPOSTToServer(data);
                })
        }).catch(function (err) {
                console.log(':^(', err);
        });




// Example navigatorPush.service.js file

var getTitle = function (title) {
        if (title === "") {
                title = "TITLE DEFAULT";
        }
        return title;
};
var getNotificationOptions = function (message, message_tag) {
        var options = {
                body: message,
                icon: '/img/icon_120.png',
                tag: message_tag,
                vibrate: [200, 100, 200, 100, 200, 100, 200]
        };
        return options;
};

self.addEventListener('install', function (event) {
        self.skipWaiting();
});

self.addEventListener('push', function(event) {
        try {
                // Push is a JSON
                var response_json = event.data.json();
                var title = response_json.title;
                var message = response_json.message;
                var message_tag = response_json.tag;
        } catch (err) {
                // Push is a simple text
                var title = "";
                var message = event.data.text();
                var message_tag = "";
        }
        self.registration.showNotification(getTitle(title), getNotificationOptions(message, message_tag));
        // Optional: Comunicating with our js application. Send a signal
        self.clients.matchAll({includeUncontrolled: true, type: 'window'}).then(function (clients) {
                clients.forEach(function (client) {
                        client.postMessage({
                                "data": message_tag,
                                "data_title": title,
                                "data_body": message});
                        });
        });
});

// Optional: Added to that the browser opens when you click on the notification push web.
self.addEventListener('notificationclick', function(event) {
        // Android doesn't close the notification when you click it
        // See http://crbug.com/463146
        event.notification.close();
        // Check if there's already a tab open with this URL.
        // If yes: focus on the tab.
        // If no: open a tab with the URL.
        event.waitUntil(clients.matchAll({type: 'window', includeUncontrolled: true}).then(function(windowClients) {
                        for (var i = 0; i < windowClients.length; i++) {
                                var client = windowClients[i];
                                if ('focus' in client) {
                                        return client.focus();
                                }
                        }
                })
        );
});

Sending messages

FCM/GCM and APNS services have slightly different semantics. The app tries to offer a common interface for both when using the models.

from push_notifications.models import APNSDevice, GCMDevice

device = GCMDevice.objects.get(registration_id=gcm_reg_id)
# The first argument will be sent as "message" to the intent extras Bundle
# Retrieve it with intent.getExtras().getString("message")
device.send_message("You've got mail")
# If you want to customize, send an extra dict and a None message.
# the extras dict will be mapped into the intent extras Bundle.
# For dicts where all values are keys this will be sent as url parameters,
# but for more complex nested collections the extras dict will be sent via
# the bulk message api.
device.send_message(None, extra={"foo": "bar"})

device = APNSDevice.objects.get(registration_id=apns_token)
device.send_message("You've got mail") # Alert message may only be sent as text.
device.send_message(None, badge=5) # No alerts but with badge.
device.send_message(None, content_available=1, extra={"foo": "bar"}) # Silent message with custom data.
# alert with title and body.
device.send_message(message={"title" : "Game Request", "body" : "Bob wants to play poker"}, extra={"foo": "bar"})
device.send_message("Hello again", thread_id="123", extra={"foo": "bar"}) # set thread-id to allow iOS to merge notifications

Sending messages in bulk

from push_notifications.models import APNSDevice, GCMDevice

devices = GCMDevice.objects.filter(user__first_name="James")
devices.send_message("Happy name day!")

Sending messages in bulk makes use of the bulk mechanics offered by GCM and APNS. It is almost always preferable to send bulk notifications instead of single ones.

It's also possible to pass badge parameter as a function which accepts token parameter in order to set different badge value per user. Assuming User model has a method get_badge returning badge count for a user:

devices.send_message(
        "Happy name day!",
        badge=lambda token: APNSDevice.objects.get(registration_id=token).user.get_badge()
)

Firebase vs Google Cloud Messaging

django-push-notifications supports both Google Cloud Messaging and Firebase Cloud Messaging (which is now the officially supported messaging platform from Google). When registering a device, you must pass the cloud_message_type parameter to set the cloud type that matches the device needs. This is currently defaulting to 'GCM', but may change to 'FCM' at some point. You are encouraged to use the officially supported library.

When using FCM, django-push-notifications will automatically use the notification and data messages format to be conveniently handled by Firebase devices. You may want to check the payload to see if it matches your needs, and review your notification statuses in FCM Diagnostic console.

# Create a FCM device
fcm_device = GCMDevice.objects.create(registration_id="token", cloud_message_type="FCM", user=the_user)

# Send a notification message
fcm_device.send_message("This is a message")

# Send a notification message with additionnal payload
fcm_device.send_message("This is a enriched message", extra={"title": "Notification title", "icon": "icon_ressource"})

# Send a notification message with additionnal payload (alternative syntax)
fcm_device.send_message("This is a enriched message", title="Notification title", badge=6)

# Send a notification message with extra data
fcm_device.send_message("This is a message with data", extra={"other": "content", "misc": "data"})

# Send a notification message with options
fcm_device.send_message("This is a message", time_to_live=3600)

# Send a data message only
fcm_device.send_message(None, extra={"other": "content", "misc": "data"})

You can disable this default behaviour by setting use_fcm_notifications to False.

fcm_device = GCMDevice.objects.create(registration_id="token", cloud_message_type="FCM", user=the_user)

# Send a data message with classic format
fcm_device.send_message("This is a message", use_fcm_notifications=False)

Sending FCM/GCM messages to topic members

FCM/GCM topic messaging allows your app server to send a message to multiple devices that have opted in to a particular topic. Based on the publish/subscribe model, topic messaging supports unlimited subscriptions per app. Developers can choose any topic name that matches the regular expression, "/topics/[a-zA-Z0-9-_.~%]+". Note: gcm_send_bulk_message must be used when sending messages to topic subscribers, and setting the first param to any value other than None will result in a 400 Http error.

from push_notifications.gcm import send_message

# First param is "None" because no Registration_id is needed, the message will be sent to all devices subscribed to the topic.
send_message(None, {"body": "Hello members of my_topic!"}, to="/topics/my_topic")

Reference: FCM Documentation

Exceptions

• NotificationError(Exception): Base exception for all notification-related errors.
• gcm.GCMError(NotificationError): An error was returned by GCM. This is never raised when using bulk notifications.
• apns.APNSError(NotificationError): Something went wrong upon sending APNS notifications.
• apns.APNSDataOverflow(APNSError): The APNS payload exceeds its maximum size and cannot be sent.

Django REST Framework (DRF) support

ViewSets are available for both APNS and GCM devices in two permission flavors:

• APNSDeviceViewSet and GCMDeviceViewSet

  • Permissions as specified in settings (AllowAny by default, which is not recommended)
  • A device may be registered without associating it with a user

• APNSDeviceAuthorizedViewSet and GCMDeviceAuthorizedViewSet

  • Permissions are IsAuthenticated and custom permission IsOwner, which will only allow the request.user to get and update devices that belong to that user
  • Requires a user to be authenticated, so all devices will be associated with a user

When creating an APNSDevice, the registration_id is validated to be a 64-character or 200-character hexadecimal string. Since 2016, device tokens are to be increased from 32 bytes to 100 bytes.

Routes can be added one of two ways:

• Routers (include all views)

from push_notifications.api.rest_framework import APNSDeviceAuthorizedViewSet, GCMDeviceAuthorizedViewSet
from rest_framework.routers import DefaultRouter

router = DefaultRouter()
router.register(r'device/apns', APNSDeviceAuthorizedViewSet)
router.register(r'device/gcm', GCMDeviceAuthorizedViewSet)

urlpatterns = patterns('',
        # URLs will show up at <api_root>/device/apns
        url(r'^', include(router.urls)),
        # ...
)

• Using as_view (specify which views to include)

from push_notifications.api.rest_framework import APNSDeviceAuthorizedViewSet

urlpatterns = patterns('',
        # Only allow creation of devices by authenticated users
        url(r'^device/apns/?$', APNSDeviceAuthorizedViewSet.as_view({'post': 'create'}), name='create_apns_device'),
        # ...
)

Update of device with duplicate registration ID

The DRF viewset enforce the uniqueness of the registration ID. In same use case it may cause issue: If an already registered mobile change its user and it will fail to register because the registration ID already exist.

When option UPDATE_ON_DUPLICATE_REG_ID is set to True, then any creation of device with an already existing registration ID will be transformed into an update.

The UPDATE_ON_DUPLICATE_REG_ID only works with DRF.