Workbox

Maxim Salnikov

Angular GDE

Building an Angular PWA:

NGSW

?

- or -

+ what's new in PWA

Maxim Salnikov

@webmaxru

Google Developer Expert in Angular
Angular Oslo / PWA Oslo meetups organizer
ngVikings / ngCommunity organizer
Leading webdev track at 404fest.ru (Samara, September 14-15)

Azure Developer Technical Lead at Microsoft

What is PWA at all?

Progressive web apps use modern web APIs along with traditional progressive enhancement strategy to create cross-platform web applications.

https://developer.mozilla.org/en-US/Apps/Progressive

These apps work everywhere and provide several features that give them the same user experience advantages as native apps.

works everywhere*

* but not everything**

natively

** use progressive enhancement strategy

UX advantages?

Smart networking + Offline

Proper app experience

Staying notified

Other cool things

}

Service Worker API

Web App Manifest

https://goo.gle/fugu-api-tracker

Almost 100 new APIs

https://developers.google.com/web/updates/2018/12/badging-api

Badging API

https://developers.google.com/web/updates/2019/08/contact-picker

Contact Picker API

https://developers.google.com/web/updates/2019/08/native-file-system

Native File System API

https://developers.google.com/web/updates/2019/08/periodic-background-sync

Periodic Background Sync API

NOT a "cron" in a browser
Works only when online
The browser is a decision maker

https://developers.google.com/web/updates/2019/06/pwa-install-addressbar

Installation

Anything else we need?

Create Angular PWA

Code service worker manually
Use Angular Service Worker (NGSW)
Use some PWA libraries

Minimum viable PWA

=

+

Application shell

Web App Manifest

Fast, responsive, mobile-first

Served via HTTPS

Logically

Physically

-file(s)

App

Service-worker

Browser/OS

Event-driven worker

Cache

fetch

push

sync

Managing cache

self.addEventListener('install', (event) => {
  
    // Put app's html/js/css to cache

})

self.addEventListener('activate', (event) => {
  
    // Wipe previous version of app files from cache

})

In the real world

Can't add opaque responses directly
Redirected requests should be managed
Always creating a new version of cache and deleting the old one is not optimal
Control over cache size is required
Cache invalidation for runtime caching is complex
...

Intercepting requests

self.addEventListener('fetch', (event) => {

  if (event.request.url.indexOf('/api') != -1) {
    event.respondWith(
      // Network-First Strategy
    )
  } else {
    event.respondWith(
      // Cache-First Strategy
    )
  }
})

In the real world

All kinds of fallbacks needed for the strategies
There are more complex strategies like Stale-While-Revalidate
Good to have routing
Good to have the possibility to provide some extra settings for different resource groups
...

Pros

Great flexibility!

Cons

Great responsibility!

Implementing complex algorithms
Adopting best practices
Focusing on YOUR task
Following specifications updates
Handling edge cases

Tools help with

NGSW

Angular Service Worker

NGSW

Automation

Scaffolding

Building

Serving

Schematics

Angular CLI

NGSW

$ ng add @angular/pwa

Scaffold

$ ng build --prod

Build

$ ng serve

Serve

ngsw-config.json

src/manifest.webmanifest

Updated

What's happened?

Built

ngsw.json

ngsw-worker.js

src/assets/icons/icon-*.png

Scaffolded

src/index.html

src/app/app.module.ts

ngsw-config.json / assetGroups

{
    "name": "app",
    "installMode": "prefetch",
    "resources":







}

    "resources": {    
        "files": [
            "/favicon.ico",
            "/index.html",
            "/*.css",
            "/*.js"
        ]
    }

Configuration file

https://angular.io/guide/service-worker-config

https://developers.google.com/web/tools/workbox/

Application shell
Runtime caching
Replaying failed network requests
Offline Google Analytics
Broadcasting updates

Have our own service worker!

Working modes

Workbox CLI
Webpack plugin
Node module

# Installing the Workbox Node module
$ npm install workbox-build --save-dev

Build script

// We will use injectManifest mode
const {injectManifest} = require('workbox-build')

// Sample configuration with the basic options
var workboxConfig = {...}

// Calling the method and output the result
injectManifest(workboxConfig).then(({count, size}) => {
    console.log(`Generated ${workboxConfig.swDest},
    which will precache ${count} files, ${size} bytes.`)
})

workbox-build-inject.js

Build script configuration

// Sample configuration with the basic options
var workboxConfig = {
  globDirectory: 'dist/angular-pwa/',
  globPatterns: [
    '**/*.{txt,png,ico,html,js,json,css}'
  ],
  swSrc: 'src/service-worker.js',
  swDest: 'dist/angular-pwa/service-worker.js'
}

workbox-build-inject.js

Source service worker

// Importing Workbox itself from Google CDN
importScripts('https://googleapis.com/.../workbox-sw.js');

// Precaching and setting up the routing
workbox.precaching.precacheAndRoute([])

src/service-worker.js

Workbox manifest

[
  {
    "url": "index.html",
    "revision": "34c45cdf166d266929f6b532a8e3869e"
  },
  {
    "url": "favicon.ico",
    "revision": "b9aa7c338693424aae99599bec875b5f"
  },
  ...
]

Build flow integration

{
  "scripts": {
    "build-prod": "ng build --prod &&
                   node workbox-build-inject.js"
  }
}

package.json

NGSW

Convenient build module
Having our own service worker and extending it by Workbox modules

One-liner to start
Seamless integration
Smart defaults

Other features?

NGSW

Events to inform about app shell updates

Runtime caching based on the strategies

Push notifications helpers

Web App Manifest

Extendable

Summary

NGSW

Easy to start
Seamless integration with Angular
Coding-free basic features
Angular-friendly approach

Add -> Configure

Get what's included

Framework-agnostic
Rich functionality
Maximum flexible configuration
Full power of our own service worker

Setup -> Configure -> Code

Get what you want

bit.ly/go-pwa-slack

2000+ developers
Representatives from the browsers, frameworks, libraries

t.me/pwa_ru

Все о PWA на русском языке

Thank you!

Maxim Salnikov

@webmaxru

Questions?

Maxim Salnikov

@webmaxru

Workbox

Building an Angular PWA:

NGSW

?

?

?

- or -

+ what's new in PWA

Maxim Salnikov

@webmaxru

Google Developer Expert in Angular

Angular Oslo / PWA Oslo meetups organizer

ngVikings / ngCommunity organizer

Leading webdev track at 404fest.ru (Samara, September 14-15)

What is PWA at all?

These apps work everywhere and provide several features that give them the same user experience advantages as native apps.

works everywhere*

natively

UX advantages?

Smart networking + Offline

Proper app experience

Staying notified

Other cool things

}

Almost 100 new APIs

Badging API

Contact Picker API

Native File System API

Periodic Background Sync API

NOT a "cron" in a browser

Works only when online

The browser is a decision maker

Installation

Anything else we need?

Create Angular PWA

Code service worker manually

Use Angular Service Worker (NGSW)

Use some PWA libraries

Minimum viable PWA

=

+

Application shell

Web App Manifest

Fast, responsive, mobile-first

Served via HTTPS

Logically

Physically

-file(s)

Managing cache

In the real world

Can't add opaque responses directly

Redirected requests should be managed

Always creating a new version of cache and deleting the old one is not optimal

Control over cache size is required

Cache invalidation for runtime caching is complex

...

Intercepting requests

In the real world

All kinds of fallbacks needed for the strategies

There are more complex strategies like Stale-While-Revalidate

Good to have routing

Good to have the possibility to provide some extra settings for different resource groups

...

Pros

Great flexibility!

Cons

Great responsibility!

Implementing complex algorithms

Adopting best practices

Focusing on YOUR task

Following specifications updates

Handling edge cases

Tools help with

NGSW

Angular Service Worker

NGSW

Automation

Scaffolding

Building

Serving