WEB PUSH Johannes Brodwall

Outline

The low down Is it time? Implementation notes Firefox Chrome Safari Implementation bits

What’s up?

What

What Notification bubbles on web and mobile

What Based on (unstable) standards

What Using major push networks Google Cloud Messaging Apple Push Notification service

Why

No installation required Don’t need to be on webpage

Why Keep users up to date Notify of pending work

Why Reach more clients with less code

How

Set up application with push service provider(s)

How Client JavaScript: navigator.serviceWorker.register <- registration registration.pushManager.subscribe <- endpointId Sends endpointId to server Application server saves endpoint

How Application server Sends a proprietary command to Push Provider Client ServiceWorker registration.showNotification

What Why How

Potential and reality

Safari OS X Mavericks October, 2013

Safari announcement screenshot

Safari Web, but not iPhone Non-standard Technologically … advanced

Chrome 42, April 21 st, 2015

Chrome Mac, PC, Android, but not iPhone Based to open standards Pretty easy to implement

Others

Firefox nightly almost there Opera experimental, but doesn’t work Internet Explorer – never? Microsoft Edge – “Under consideration”

Trouble

Permissions HTTPS SSL (APNs)

Ready?

Today ~ 50% desktops and ~40% mobiles Optional value added feature

Yes – as optional feature

Implementation

Implementing registration 1. Setup application with push provider 2. Client starts JavaScript service worker 3. Client requests permissions 4. Client registers with push provider 5. Client sends endpointId to app server

Implementing notification 1. App server notifies push provider 2. Push service awakens service worker on client 3. Service worker fetches message from app server 4. Service worker shows notification

== Register a user for push notifications == User -> webpage: Click registration webpage -> serviceworker:register webpage -> browser: subscribe browser -> GCM: subscribe webpage <-- browser: endpointId webpage -> appserver: endpointId User -> webpage: Closes window

== Send push notifications == [-> appserver: Send message to user appserver -> GCM: POST endpoints GCM -> serviceworker: onpush() serviceworker -> appserver: GET /last-message serviceworker -> browser: showNotification browser -> User: Shows notification User -> browser: Clicks notification browser -> serviceworker: onnotificationclick() serviceworker -> browser: openWindow browser -> webpage: Display webpage webpage -> User

Firefox (Nightly)

No registration needed with Mozilla push Do HTTP PUT to endpointId

TODO: Code for app server

TODO: Code for service worker

Implementation bits

Promises Permissions ExpressJs

Implementation bits Promises Permissions ExpressJs

Implementation bits Promises Permissions ExpressJs

Chrome

Register application with Google Developer Console Do HTTP POST with a list of endpointIds as JSON payload

TODO: Code for service worker

Safari

Apple Push Notification service Get SSL certificate from Apple Create push package (zip file with ssl signature) Request push permission Send payload to Apple over ssh port 2195

Create push package

Open SSL reference 1. Getting the key and pem cert files openssl genrsa -out.key 2048 openssl req -new -sha256 -key.key –out.csr Sign.csr with Apple and get.cer openssl x509 –in website_aps_production.cer –inform DER –out website_aps_production.pem –outform PEM

Files.key – private key in PEM (readable) format – keep secret!.csr – Certificate signing request in in PEM (readable) format – give to Apple and then discard website_aps_production.cer – Valid certificate you get from Apple in DER (binary) format website_aps_production.pem – Valid certificate in PEM (readable) format

Open SSL reference 2. Signing files openssl smime -sign -signer certificate.pem -inkey.key -in -binary -outform DER -out signature file Verify signature (for debugging) openssl smime –verify –in signature file –inform DER –content –noverify

Registering client

Sending push notifications

Cordova

Cordova/Adobe Phonegap Supports Android, iOS, Windows Push notifications through 3 rd party plugin (not Windows) Uses APNs and GCM (like web push)

Azure

Azure notification hubs Provides common contact point Doesn’t actually solve the hard bits

Summary

Push API Provides web push to almost ½ of desktop market now Only web supported on Chrome (50%), but look out for Firefox (15%)! Replaces many apps on Android Easy to implement

Safari push Not supported on mobile Needlessly hard to implement, but APNs is also needed for iOS apps

Implementation bits Promises ExpressJS Permissions

My last mobile app used Cordova My next will be pure web for Android

THANK YOU