如何通过匹配Angular 8中的值来更改数据

ng generate pipe matchValue

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'matchValue'
})
export class MatchValuePipe implements PipeTransform {

  transform(value: any, match: any, replacement: any): any {
    return value === match ? replacement : value;
  }

}

<p>{{ someValue | matchValue:'oldValue':'newValue' }}</p>

export class MyComponent {
  someValue = 'oldValue';

  getMatchedValue(value: string, match: string, replacement: string): string {
    return value === match ? replacement : value;
  }
}

<p>{{ getMatchedValue(someValue, 'oldValue', 'newValue') }}</p>

ng generate service match-value

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class MatchValueService {

  matchValue(value: any, match: any, replacement: any): any {
    return value === match ? replacement : value;
  }

}

import { Component } from '@angular/core';
import { MatchValueService } from './match-value.service';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent {
  someValue = 'oldValue';

  constructor(private matchValueService: MatchValueService) {}

  getMatchedValue(): string {
    return this.matchValueService.matchValue(this.someValue, 'oldValue', 'newValue');
  }
}

<p>{{ getMatchedValue() }}</p>