4

Angular2 RC3 (Angular-CLI を使用) で最初のアプリを試したところ、これで迷ってしまいました...

variable の「変更検出」に問題がありますword。Observablewordのメソッド内の変数を更新しましたが、変更は検出されませんでした。subscribe

app.component.ts

import { Component, Inject, OnInit } from '@angular/core';
import { VoiceRecognitionService } from './voice-recognition.service';

@Component({
  moduleId: module.id,
  selector: 'app-root',
  template: `<h1>{{word}}</h1>`, // => No prints any update
  providers: [VoiceRecognitionService],
  styleUrls: ['app.component.css']
})
export class AppComponent implements OnInit {

  private voice: VoiceRecognitionService;
  public word: string = '';

  constructor( @Inject(VoiceRecognitionService) voiceRecognition: VoiceRecognitionService) {
    this.voice = voiceRecognition;
  }

  ngOnInit() {
    this.voice.record('ca')
      .subscribe(word => {
        console.log(word); // => Is printing well the new word
        this.word = `${word}...`; // => No changes detected
      });
  }
}

Angular 1$scope.$applyで同様のケースに を使用したことを覚えています。同じように Angular2 を検索したところNgZone.run、 が見つかりました。内部NgZone.runで実行しようとしましたが、何もありませんでした。

私が間違っていることは何ですか？

どうもありがとう。

追加：

サービスを Observable と共有します。

音声認識.service.ts

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Rx';

export interface IWindow extends Window {
  webkitSpeechRecognition: any;
}

@Injectable()
export class VoiceRecognitionService {

  constructor() {
    /* void */
  }

  /**
   * Record
   * @param {string} language - Language of the voice recognition
   * @returns {Observable<string>} - Observable of voice converted to string 
   */
  record(language: string): Observable<string> {
    return Observable.create((observer) => {
      const { webkitSpeechRecognition }: IWindow = <IWindow>window;
      const recognition = new webkitSpeechRecognition();

      recognition.onresult = (e) => observer.next(e.results.item(e.results.length - 1).item(0).transcript);
      recognition.onerror = observer.error;
      recognition.onend = observer.completed;

      recognition.continuous = true;
      recognition.interimResults = true;
      recognition.lang = language;
      recognition.start();
    });
  }
}
4

2 に答える 2

10

I assume the webkitSpeechRecognition API is not patched by Angulars zone.

To work around use zone.run(...) to force the execution back into Angulars zone explicitely:

@Injectable()
export class VoiceRecognitionService {

  constructor(private zone:NgZone) {
    /* void */
  }

  /**
   * Record
   * @param {string} language - Language of the voice recognition
   * @returns {Observable<string>} - Observable of voice converted to string 
   */
  record(language: string): Observable<string> {
    return Observable.create((observer) => {
      const { webkitSpeechRecognition }: IWindow = <IWindow>window;
      const recognition = new webkitSpeechRecognition();

      recognition.onresult = (e) => this.zone.run(() => observer.next(e.results.item(e.results.length - 1).item(0).transcript));
      recognition.onerror = (e) => this.zone.run(() => observer.error(e));
      recognition.onend = (e) => this.zone.run(() => observer.completed(e));

      recognition.continuous = true;
      recognition.interimResults = true;
      recognition.lang = language;
      recognition.start();
    });
  }
}

If the callbacks need a different number of parameters ((e)) please adjust the code accordingly. I just assumed one parameter for each.

The advantage of this approach is that the users of this service don't have to take additional measures.

于 2016-06-29T12:56:35.497 に答える