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import { Component, Input } from '@angular/core';
 
import { Hero } from './hero';
 
@Component({
  selector: 'app-hero-child',
  template: `
    <h3>{{hero.name}} says:</h3>
    <p>I, {{hero.name}}, am at your service, {{masterName}}.</p>
  `
})
export class HeroChildComponent {
  @Input() hero: Hero;
  @Input('master') masterName: string;
}
    

      
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import { Component } from '@angular/core';
 
import { HEROES } from './hero';
 
@Component({
  selector: 'app-hero-parent',
  template: `
    <h2>{{master}} controls {{heroes.length}} heroes</h2>
    <app-hero-child *ngFor="let hero of heroes"
      [hero]="hero"
      [master]="master">
    </app-hero-child>
  `
})
export class HeroParentComponent {
  heroes = HEROES;
  master = 'Master';
}
    

      
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// ...
let _heroNames = ['Mr. IQ', 'Magneta', 'Bombasto'];
let _masterName = 'Master';
 
it('should pass properties to children properly', function () {
  let parent = element.all(by.tagName('app-hero-parent')).get(0);
  let heroes = parent.all(by.tagName('app-hero-child'));
 
  for (let i = 0; i < _heroNames.length; i++) {
    let childTitle = heroes.get(i).element(by.tagName('h3')).getText();
    let childDetail = heroes.get(i).element(by.tagName('p')).getText();
    expect(childTitle).toEqual(_heroNames[i] + ' says:');
    expect(childDetail).toContain(_masterName);
  }
});
// ...
    

      
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import { Component, Input } from '@angular/core';
 
@Component({
  selector: 'app-name-child',
  template: '<h3>"{{name}}"</h3>'
})
export class NameChildComponent {
  private _name = '';
 
  @Input()
  set name(name: string) {
    this._name = (name && name.trim()) || '<no name set>';
  }
 
  get name(): string { return this._name; }
}
    

      
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import { Component } from '@angular/core';
 
@Component({
  selector: 'app-name-parent',
  template: `
  <h2>Master controls {{names.length}} names</h2>
  <app-name-child *ngFor="let name of names" [name]="name"></app-name-child>
  `
})
export class NameParentComponent {
  // Displays 'Mr. IQ', '<no name set>', 'Bombasto'
  names = ['Mr. IQ', '   ', '  Bombasto  '];
}
    

      
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// ...
it('should display trimmed, non-empty names', function () {
  let _nonEmptyNameIndex = 0;
  let _nonEmptyName = '"Mr. IQ"';
  let parent = element.all(by.tagName('app-name-parent')).get(0);
  let hero = parent.all(by.tagName('app-name-child')).get(_nonEmptyNameIndex);
 
  let displayName = hero.element(by.tagName('h3')).getText();
  expect(displayName).toEqual(_nonEmptyName);
});
 
it('should replace empty name with default name', function () {
  let _emptyNameIndex = 1;
  let _defaultName = '"<no name set>"';
  let parent = element.all(by.tagName('app-name-parent')).get(0);
  let hero = parent.all(by.tagName('app-name-child')).get(_emptyNameIndex);
 
  let displayName = hero.element(by.tagName('h3')).getText();
  expect(displayName).toEqual(_defaultName);
});
// ...
    

      
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import { Component, Input, OnChanges, SimpleChange } from '@angular/core';
 
@Component({
  selector: 'app-version-child',
  template: `
    <h3>Version {{major}}.{{minor}}</h3>
    <h4>Change log:</h4>
    <ul>
      <li *ngFor="let change of changeLog">{{change}}</li>
    </ul>
  `
})
export class VersionChildComponent implements OnChanges {
  @Input() major: number;
  @Input() minor: number;
  changeLog: string[] = [];
 
  ngOnChanges(changes: {[propKey: string]: SimpleChange}) {
    let log: string[] = [];
    for (let propName in changes) {
      let changedProp = changes[propName];
      let to = JSON.stringify(changedProp.currentValue);
      if (changedProp.isFirstChange()) {
        log.push(`Initial value of ${propName} set to ${to}`);
      } else {
        let from = JSON.stringify(changedProp.previousValue);
        log.push(`${propName} changed from ${from} to ${to}`);
      }
    }
    this.changeLog.push(log.join(', '));
  }
}
    

      
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import { Component } from '@angular/core';
 
@Component({
  selector: 'app-version-parent',
  template: `
    <h2>Source code version</h2>
    <button (click)="newMinor()">New minor version</button>
    <button (click)="newMajor()">New major version</button>
    <app-version-child [major]="major" [minor]="minor"></app-version-child>
  `
})
export class VersionParentComponent {
  major = 1;
  minor = 23;
 
  newMinor() {
    this.minor++;
  }
 
  newMajor() {
    this.major++;
    this.minor = 0;
  }
}
    

      
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// ...
// Test must all execute in this exact order
it('should set expected initial values', function () {
  let actual = getActual();
 
  let initialLabel = 'Version 1.23';
  let initialLog = 'Initial value of major set to 1, Initial value of minor set to 23';
 
  expect(actual.label).toBe(initialLabel);
  expect(actual.count).toBe(1);
  expect(actual.logs.get(0).getText()).toBe(initialLog);
});
 
it('should set expected values after clicking \'Minor\' twice', function () {
  let repoTag = element(by.tagName('app-version-parent'));
  let newMinorButton = repoTag.all(by.tagName('button')).get(0);
 
  newMinorButton.click().then(function() {
    newMinorButton.click().then(function() {
      let actual = getActual();
 
      let labelAfter2Minor = 'Version 1.25';
      let logAfter2Minor = 'minor changed from 24 to 25';
 
      expect(actual.label).toBe(labelAfter2Minor);
      expect(actual.count).toBe(3);
      expect(actual.logs.get(2).getText()).toBe(logAfter2Minor);
    });
  });
});
 
it('should set expected values after clicking \'Major\' once', function () {
  let repoTag = element(by.tagName('app-version-parent'));
  let newMajorButton = repoTag.all(by.tagName('button')).get(1);
 
  newMajorButton.click().then(function() {
    let actual = getActual();
 
    let labelAfterMajor = 'Version 2.0';
    let logAfterMajor = 'major changed from 1 to 2, minor changed from 25 to 0';
 
    expect(actual.label).toBe(labelAfterMajor);
    expect(actual.count).toBe(4);
    expect(actual.logs.get(3).getText()).toBe(logAfterMajor);
  });
});
 
function getActual() {
  let versionTag = element(by.tagName('app-version-child'));
  let label = versionTag.element(by.tagName('h3')).getText();
  let ul = versionTag.element((by.tagName('ul')));
  let logs = ul.all(by.tagName('li'));
 
  return {
    label: label,
    logs: logs,
    count: logs.count()
  };
}
// ...
    

      
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import { Component, EventEmitter, Input, Output } from '@angular/core';
 
@Component({
  selector: 'app-voter',
  template: `
    <h4>{{name}}</h4>
    <button (click)="vote(true)"  [disabled]="didVote">Agree</button>
    <button (click)="vote(false)" [disabled]="didVote">Disagree</button>
  `
})
export class VoterComponent {
  @Input()  name: string;
  @Output() voted = new EventEmitter<boolean>();
  didVote = false;
 
  vote(agreed: boolean) {
    this.voted.emit(agreed);
    this.didVote = true;
  }
}
    

      
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import { Component }      from '@angular/core';
 
@Component({
  selector: 'app-vote-taker',
  template: `
    <h2>Should mankind colonize the Universe?</h2>
    <h3>Agree: {{agreed}}, Disagree: {{disagreed}}</h3>
    <app-voter *ngFor="let voter of voters"
      [name]="voter"
      (voted)="onVoted($event)">
    </app-voter>
  `
})
export class VoteTakerComponent {
  agreed = 0;
  disagreed = 0;
  voters = ['Mr. IQ', 'Ms. Universe', 'Bombasto'];
 
  onVoted(agreed: boolean) {
    agreed ? this.agreed++ : this.disagreed++;
  }
}
    

      
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// ...
it('should not emit the event initially', function () {
  let voteLabel = element(by.tagName('app-vote-taker'))
    .element(by.tagName('h3')).getText();
  expect(voteLabel).toBe('Agree: 0, Disagree: 0');
});
 
it('should process Agree vote', function () {
  let agreeButton1 = element.all(by.tagName('app-voter')).get(0)
    .all(by.tagName('button')).get(0);
  agreeButton1.click().then(function() {
    let voteLabel = element(by.tagName('app-vote-taker'))
      .element(by.tagName('h3')).getText();
    expect(voteLabel).toBe('Agree: 1, Disagree: 0');
  });
});
 
it('should process Disagree vote', function () {
  let agreeButton1 = element.all(by.tagName('app-voter')).get(1)
    .all(by.tagName('button')).get(1);
  agreeButton1.click().then(function() {
    let voteLabel = element(by.tagName('app-vote-taker'))
      .element(by.tagName('h3')).getText();
    expect(voteLabel).toBe('Agree: 1, Disagree: 1');
  });
});
// ...
    

      
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import { Component, OnDestroy, OnInit } from '@angular/core';
 
@Component({
  selector: 'app-countdown-timer',
  template: '<p>{{message}}</p>'
})
export class CountdownTimerComponent implements OnInit, OnDestroy {
 
  intervalId = 0;
  message = '';
  seconds = 11;
 
  clearTimer() { clearInterval(this.intervalId); }
 
  ngOnInit()    { this.start(); }
  ngOnDestroy() { this.clearTimer(); }
 
  start() { this.countDown(); }
  stop()  {
    this.clearTimer();
    this.message = `Holding at T-${this.seconds} seconds`;
  }
 
  private countDown() {
    this.clearTimer();
    this.intervalId = window.setInterval(() => {
      this.seconds -= 1;
      if (this.seconds === 0) {
        this.message = 'Blast off!';
      } else {
        if (this.seconds < 0) { this.seconds = 10; } // reset
        this.message = `T-${this.seconds} seconds and counting`;
      }
    }, 1000);
  }
}
    

      
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import { Component }                from '@angular/core';
import { CountdownTimerComponent }  from './countdown-timer.component';
 
@Component({
  selector: 'app-countdown-parent-lv',
  template: `
  <h3>Countdown to Liftoff (via local variable)</h3>
  <button (click)="timer.start()">Start</button>
  <button (click)="timer.stop()">Stop</button>
  <div class="seconds">{{timer.seconds}}</div>
  <app-countdown-timer #timer></app-countdown-timer>
  `,
  styleUrls: ['../assets/demo.css']
})
export class CountdownLocalVarParentComponent { }
    

      
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// ...
it('timer and parent seconds should match', function () {
  let parent = element(by.tagName(parentTag));
  let message = parent.element(by.tagName('app-countdown-timer')).getText();
  browser.sleep(10); // give `seconds` a chance to catchup with `message`
  let seconds = parent.element(by.className('seconds')).getText();
  expect(message).toContain(seconds);
});
 
it('should stop the countdown', function () {
  let parent = element(by.tagName(parentTag));
  let stopButton = parent.all(by.tagName('button')).get(1);
 
  stopButton.click().then(function() {
    let message = parent.element(by.tagName('app-countdown-timer')).getText();
    expect(message).toContain('Holding');
  });
});
// ...
    

      
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import { AfterViewInit, ViewChild } from '@angular/core';
import { Component }                from '@angular/core';
import { CountdownTimerComponent }  from './countdown-timer.component';
 
@Component({
  selector: 'app-countdown-parent-vc',
  template: `
  <h3>Countdown to Liftoff (via ViewChild)</h3>
  <button (click)="start()">Start</button>
  <button (click)="stop()">Stop</button>
  <div class="seconds">{{ seconds() }}</div>
  <app-countdown-timer></app-countdown-timer>
  `,
  styleUrls: ['../assets/demo.css']
})
export class CountdownViewChildParentComponent implements AfterViewInit {
 
  @ViewChild(CountdownTimerComponent)
  private timerComponent: CountdownTimerComponent;
 
  seconds() { return 0; }
 
  ngAfterViewInit() {
    // Redefine `seconds()` to get from the `CountdownTimerComponent.seconds` ...
    // but wait a tick first to avoid one-time devMode
    // unidirectional-data-flow-violation error
    setTimeout(() => this.seconds = () => this.timerComponent.seconds, 0);
  }
 
  start() { this.timerComponent.start(); }
  stop() { this.timerComponent.stop(); }
}
    

      
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import { Injectable } from '@angular/core';
import { Subject }    from 'rxjs';
 
@Injectable()
export class MissionService {
 
  // Observable string sources
  private missionAnnouncedSource = new Subject<string>();
  private missionConfirmedSource = new Subject<string>();
 
  // Observable string streams
  missionAnnounced$ = this.missionAnnouncedSource.asObservable();
  missionConfirmed$ = this.missionConfirmedSource.asObservable();
 
  // Service message commands
  announceMission(mission: string) {
    this.missionAnnouncedSource.next(mission);
  }
 
  confirmMission(astronaut: string) {
    this.missionConfirmedSource.next(astronaut);
  }
}
    

      
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import { Component }          from '@angular/core';
 
import { MissionService }     from './mission.service';
 
@Component({
  selector: 'app-mission-control',
  template: `
    <h2>Mission Control</h2>
    <button (click)="announce()">Announce mission</button>
    <app-astronaut *ngFor="let astronaut of astronauts"
      [astronaut]="astronaut">
    </app-astronaut>
    <h3>History</h3>
    <ul>
      <li *ngFor="let event of history">{{event}}</li>
    </ul>
  `,
  providers: [MissionService]
})
export class MissionControlComponent {
  astronauts = ['Lovell', 'Swigert', 'Haise'];
  history: string[] = [];
  missions = ['Fly to the moon!',
              'Fly to mars!',
              'Fly to Vegas!'];
  nextMission = 0;
 
  constructor(private missionService: MissionService) {
    missionService.missionConfirmed$.subscribe(
      astronaut => {
        this.history.push(`${astronaut} confirmed the mission`);
      });
  }
 
  announce() {
    let mission = this.missions[this.nextMission++];
    this.missionService.announceMission(mission);
    this.history.push(`Mission "${mission}" announced`);
    if (this.nextMission >= this.missions.length) { this.nextMission = 0; }
  }
}
    

      
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import { Component, Input, OnDestroy } from '@angular/core';
 
import { MissionService } from './mission.service';
import { Subscription }   from 'rxjs';
 
@Component({
  selector: 'app-astronaut',
  template: `
    <p>
      {{astronaut}}: <strong>{{mission}}</strong>
      <button
        (click)="confirm()"
        [disabled]="!announced || confirmed">
        Confirm
      </button>
    </p>
  `
})
export class AstronautComponent implements OnDestroy {
  @Input() astronaut: string;
  mission = '<no mission announced>';
  confirmed = false;
  announced = false;
  subscription: Subscription;
 
  constructor(private missionService: MissionService) {
    this.subscription = missionService.missionAnnounced$.subscribe(
      mission => {
        this.mission = mission;
        this.announced = true;
        this.confirmed = false;
    });
  }
 
  confirm() {
    this.confirmed = true;
    this.missionService.confirmMission(this.astronaut);
  }
 
  ngOnDestroy() {
    // prevent memory leak when component destroyed
    this.subscription.unsubscribe();
  }
}
    

      
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// ...
it('should announce a mission', function () {
  let missionControl = element(by.tagName('app-mission-control'));
  let announceButton = missionControl.all(by.tagName('button')).get(0);
  announceButton.click().then(function () {
    let history = missionControl.all(by.tagName('li'));
    expect(history.count()).toBe(1);
    expect(history.get(0).getText()).toMatch(/Mission.* announced/);
  });
});
 
it('should confirm the mission by Lovell', function () {
  testConfirmMission(1, 2, 'Lovell');
});
 
it('should confirm the mission by Haise', function () {
  testConfirmMission(3, 3, 'Haise');
});
 
it('should confirm the mission by Swigert', function () {
  testConfirmMission(2, 4, 'Swigert');
});
 
function testConfirmMission(buttonIndex: number, expectedLogCount: number, astronaut: string) {
  let _confirmedLog = ' confirmed the mission';
  let missionControl = element(by.tagName('app-mission-control'));
  let confirmButton = missionControl.all(by.tagName('button')).get(buttonIndex);
  confirmButton.click().then(function () {
    let history = missionControl.all(by.tagName('li'));
    expect(history.count()).toBe(expectedLogCount);
    expect(history.get(expectedLogCount - 1).getText()).toBe(astronaut + _confirmedLog);
  });
}
// ...