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[enterjs] From Bleeding Edge to World Class: On...

[enterjs] From Bleeding Edge to World Class: One Year with Angular

On March 31, 2016, NPR launched a production web app built with Angular 2, which was still in beta at the time; the final, stable release of v2.0 went live on September 14.
As early adopters, we faced challenges ranging from convincing internal stakeholders to put our fates in the hands of a pre-release framework, to collaborating with a different team that was using React, to making technical design decisions while navigating API changes and incomplete documentation.
Come learn what we love the most about Angular, the best resources for getting started, what we would do differently if we were to start all over again, and why we think you might want to consider using it for your next project.

Nara Kasbergen

June 21, 2017
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  1. From Bleeding Edge to World Class: One Year with Angular

    Nara Kasbergen (@xiehan) | Full-stack Developer | NPR + =
  2. 2009 Miško Hevery and Adam Abrons start GetAngular at Brat

    Tech LLC, then release it as an open-source library
  3. October 20, 2010 The first public release (by the new

    AngularJS team at Google) of AngularJS, at v0.9.0
  4. July 26, 2012 The AngularJS team announces that they are

    making significant changes for v1.2.0, "targeting release in early to mid September 2012"
  5. March 18, 2014 The AngularJS team announces on their blog

    that work has begun on Angular 2.0, which is a complete, from-the-ground-up redesign
  6. October 2014 At the ngEurope conference, the Angular team announces

    that the Angular 2.0 API will not be backwards-compatible with AngularJS 1.x
  7. March 5, 2015 At ngConf (in Vegas), the Angular team

    announces that the upcoming AngularJS v1.5.x releases will focus on helping apps migrate to Angular 2
  8. October 6, 2015 The Angular team walks back previous comments

    that Angular 2 would not support older browsers like IE 9, Android 4.1 and iOS 7
  9. June 9, 2016 The Angular team announces the alpha release

    of v3.0 of the independently-packaged router in response to feedback on v2.0 of the router
  10. September 27, 2016 At AngularConnect in London, the Angular team

    announces that all future Angular releases will follow semantic versioning
  11. 2 0 0 . . Major . Minor . Patch

    Incompatible Changes Backwards Compatible Bug Fixes semver.org
  12. December 9, 2016 At the NG-BE conference in Belgium, Igor

    Minar announces that the next Angular version will be 4 (not 3) because of the router being at v3 already
  13. Remember that AngularJS started in 2009 • jQuery was still

    considered to be the gold standard of frontend development • Smart phone adoption in the US was still at 25%; mobile browser technology was in its infancy • ES5 was released in December 2009 • Web components were not even on the radar yet
  14. The core changes in v2.0+ at a high level •

    Angular now uses a strategy similar to a virtual DOM to render HTML, drastically improving how it does change detection under the hood • Controllers and Directives have been replaced by Components, intended to be compatible with the web components of the not-so-distant future
  15. Why people used, and loved, AngularJS • It made frontend

    testing much easier and more accessible than any framework ever had before • It was touted as an all-in-one framework that gave you all the fundamental features that you need • It scaled well to large, enterprise-grade projects • Google "seal of confidence"
  16. Why we picked Angular • We had the rare opportunity

    to start a project from scratch, which opened up our options • The "all-in-one" nature fit well with our project as a self-contained unit, separate from NPR.org • As a team with no embedded QA engineer, achieving a high level of test coverage was critical
  17. Why we picked Angular, continued • We don't believe in

    "one framework to rule them all" • All our research led us to conclude that React and Angular share many of the same core ideas • We had a hypothesis that there is a place in every team's stack for both React and Angular, and this was one of our only opportunities to test it
  18. January 31, 2016 I push the first (private) commit for

    the rebuild of NPR One for the Web (http://one.npr.org)
  19. March 31, 2016 NPR Digital Media launches its newly-rebuilt NPR

    One for the Web (http://one.npr.org), built with Angular
  20. An example of a basic Angular component import { Component

    } from '@angular/core'; @Component({ selector: 'my-app', template: ` <h1>{{title}}</h1> <h2>{{hero.name}} details!</h2> `, }) class AppComponent { constructor() { this.title = 'Tour of Heroes'; this.hero = { name: 'Windstorm' }; } }
  21. An example of an ngModule import { NgModule } from

    '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { FormsModule } from '@angular/forms'; import { AppComponent } from './app.component'; @NgModule({ imports: [ BrowserModule, FormsModule ], declarations: [ AppComponent ], bootstrap: [ AppComponent ] }) class AppModule { }
  22. An example of an Injectable import { Injectable } from

    '@angular/core'; const HEROES = [ {id: 11, name: 'Mr. Nice'}, {id: 12, name: 'Narco'}, {id: 13, name: 'Bombasto'}, {id: 14, name: 'Celeritas'}, {id: 15, name: 'Magneta'}, ]; @Injectable() class HeroService { getHeroes() { return Promise.resolve(HEROES); } }
  23. • Injectables basically are the replacement for the concept of

    "services" in AngularJS • Services were so widely used in the AngularJS community that you'll likely see the community continue to use that nomenclature for Injectables • Use them to improve your app's unit-testability Services are dead, long live services!
  24. Structuring your project • Continue to follow AngularJS community standard

    of grouping code in folders by feature, not by function ◦ DON'T: put all your components in one folder, services in another, etc. ◦ DO: put your ProfileComponent and ProfileService in a profile folder, for example
  25. Structuring your project, cont. • Introduction of ngModule helps enforce

    this pattern • A common Angular convention is to include the type of class in the filename, eg. profile.component.js profile.service.js profile.module.js
  26. You have a few decisions to make 1. Which flavor

    of JavaScript will you use? (ES5, ES6, or TypeScript) 2. Which build system will you use? (System.js, jspm, Webpack, or Browserify) 3. Will you attempt to use RxJS or not? 4. How will you manage application state?
  27. We picked ES6 over TypeScript • Nobody else in our

    department uses TypeScript • We wanted to make sure developers outside of our team can read and understand our code, and feel empowered to participate in code reviews • At the time, there were no features that were only available to TypeScript users
  28. Should you use ES5, ES6 or TS with Angular? •

    Use ES5 only if you've got legacy code to migrate or there are other clear infrastructure barriers • Use TypeScript if you want to take advantage of the newest features like AoT or want the best docs • Use ES6 if you're working with other teams using ES6, and collaboration and/or code-sharing are key
  29. We chose Webpack as our build system • Tried System.js,

    but at the time, documentation was quite poor (it has improved since then) • Struggled particularly with how to bring in 3rd party modules with System.js • No prior experience with jspm or Browserify • The team using React had experience using Webpack
  30. We said yes to RxJS • Figured this was our

    best opportunity to try it out and see why the Angular team recommends it. • If you've never seen it, it will hurt your brain. A lot. • It's so powerful, it's worth it to try to use it. Google and Stack Overflow are your friends if you're stuck. • ...but you can live without it if you're just starting out.
  31. Benefit of RxJS: The async pipe import { Component }

    from '@angular/core'; import { Observable } from 'rxjs/Observable'; @Component({ selector: 'hero-message', template: ` <p>Message: {{ message$ | async }}</p> `, }) class HeroAsyncMessageComponent { message$: Observable<string>; }
  32. We picked ngrx/store for state management • We wanted to

    try out RxJS • In many ways, Redux duplicates functionality that is already provided by RxJS • Therefore, we wanted Redux-like functionality that harnesses RxJS, and @ngrx/store fit the bill: github.com/ngrx/store
  33. Example reducer import { Reducer, Action } from '@ngrx/store'; import

    ActionTypes from '../app/action-types.constants'; const explore: Reducer = (state = initialState, action: Action) => { switch (action.type) { case ActionTypes.RECOMMENDATIONS_UPDATING: return Object.assign({}, state, { isLoading: true, }); ... } };
  34. Example actions import { Action } from '@ngrx/store'; import ActionTypes

    from '../app/action-types.constants'; const ExploreActions = { load(channel = 'recommended'): Action { return { type: ActionTypes.RECOMMENDATIONS_UPDATING, payload: { channel }, }; }, ... };
  35. Putting it all together with the Store import { NgModule

    } from '@angular/core' import { StoreModule } from '@ngrx/store'; import explore from './explore/explore.reducer'; import nav from './nav/nav.reducer'; import player from './player/player.reducer'; @NgModule({ imports: [..., StoreModule.forRoot({ explore, nav, player }) ] }) class AppModule {}
  36. The Store in action in a component import { Store

    } from '@ngrx/store'; @Component({ selector: 'my-app', template: ` <div>Current Count: {{ counter$ | async }}</div> `, }) class MyAppComponent { constructor(store: Store) { this.counter$ = store.select('counter'); } }
  37. • React and Angular share many of the same core

    ideas • There is a place in every team's stack for both
  38. Our hypothesis was correct • Thanks in large part to

    our decisions to use ES6 and a Redux-like state management plugin, the React developers have been able to participate in all of our code reviews • Angular worked well for us because it is all-in-one and the superior testing infrastructure was critical
  39. Resources that helped us get off the ground • Victor

    Savkin's blog: vsavkin.com • "The introduction to Reactive Programming you've been missing" by André Staltz (GitHub gist) • github.com/AngularClass/angular2-webpack-starter • angularclass.github.io/awesome-angular
  40. Plugins • AngularJS plugins are generally incompatible with Angular versions

    2 and up • Many popular UI plugins like Material, Bootstrap, etc. are still in alpha/beta release stage • Most available plugins only have documentation in TypeScript (another reason to make the switch)
  41. Testing • Default stack: Jasmine + Karma for unit tests,

    Jasmine + Protractor for end-to-end tests ◦ … but you can also use Mocha, Cucumber, etc. • ng convention: put unit tests next to source code • Protractor also now is focusing development on TypeScript (yet another reason to make the switch)
  42. NativeScript & React Native • You can use Angular to

    write apps that compile down into native iOS and Android (and soon Universal Windows) projects. So cool! • You can't just use a regular Angular webapp; among other things, you must rewrite all your templates • React Native for Angular is not well-maintained
  43. Not ready to upgrade from AngularJS yet? • At least

    start using AngularJS v1.5+ and start writing your code in components • Switch from Gulp or Grunt to Webpack or Browserify • When you're ready, the Upgrade Guide is great: angular.io/docs/ts/latest/guide/upgrade.html
  44. One year with Angular at NPR Angular: ng2 + ES6:

    TypeScript: System.js: Webpack: angular-cli: Dependency Injection: Unit Testing: Protractor: RxJS: @ngrx/store: The Angular team: