Question

如果数字是字符串格式且字符串中没有小数点，则Angular currency pipe不会将字符串/ int转换为货币格式。

假设金额为12，我想显示12.00美元，如果通过“12”，则不显示但是如果12.00通过则其正常工作。

//Code

import {Pipe, PipeTransform} from "@angular/core";
import {CurrencyPipe} from "@angular/common";
const _NUMBER_FORMAT_REGEXP = /^(\d+)?\.((\d+)(-(\d+))?)?$/;

@Pipe({name: 'myCurrency'})
export class MyCurrencyPipe implements PipeTransform  {
  constructor (private _currencyPipe: CurrencyPipe) {}

  transform(value: any, currencyCode: string, symbolDisplay: boolean, digits: string): string {
    if (typeof value === 'number' || _NUMBER_FORMAT_REGEXP.test(value)) {
      return this._currencyPipe.transform(value, currencyCode, symbolDisplay, digits);
    } else {
      return value;
    }
  }
}


@Component({
  selector: 'my-app',
  template: `
    <div>
      <h2>Hello {{name}}</h2>
      <div>{{priceNoDecimal}}</div> {{priceNoDecimal | myCurrency}}
      <div>{{priceWithDecimal}}</div> {{priceWithDecimal | myCurrency}}      
    </div>
  `,
})
export class App {
  name:string;
  priceWithDecimal: string;
  priceNoDecimal: string;
  constructor() {
    this.name = 'Angular2',
    this.priceNoDecimal = "12"
    this.priceWithDecimal = "12.00"
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App , MyCurrencyPipe],
  providers: [CurrencyPipe],
  bootstrap: [ App ]
})
export class AppModule {}


//output

Hello Angular2

12
12
12.00
USD12.00

Plunker

Answer 1

如果查看已应用的正则表达式：/^(\d+)?\.((\d+)(-(\d+))?)?$/，则需要小数点。

以下正则表达式使小数点可选/^(\d+)?\.?((\d+)(-(\d+))?)?$/

Answer 2

如果没有上下文，问题可能不清楚。来自the previous answer的管道是用于检测字符串中数字的正则表达式that is used in original number pipes：

const _NUMBER_FORMAT_REGEXP = /^(\d+)?\.((\d+)(-(\d+))?)?$/;

为了使其密切模仿input conditioning of original currency pipe，管道可能会更改为：

function isNumeric(value: any): boolean {
  return !isNaN(value - parseFloat(value));
}

@Pipe({name: 'looseCurrency'})
export class LooseCurrencyPipe implements PipeTransform {
  constructor(private _currencyPipe: CurrencyPipe) {}

  transform(value: any, currencyCode: string, symbolDisplay: boolean, digits: string): string {
    value = typeof value === 'string' && isNumeric(value) ? +value : value;

    if (typeof value === 'number') {
      return this._currencyPipe.transform(value, currencyCode, symbolDisplay, digits);
    } else {
      return value;
    }
  }
}

其中isNumeric是从framework internals中提取的辅助函数。使用这种方法应该work fine。

如果输入中没有小数点，则角度扩展货币管道输入不会格式化字符串/ int

2 个答案: