RxJS映射数组与另一个可观察值和返回数组

时间:2019-07-11 09:19:35

标签: javascript arrays angular object ecmascript-6

我有一些来自服务器的选项

const options = [
  {key: 1, label: 'label1'},
  {key: 2, label: 'label2'},
  {key: 3, label: 'label3'},
  {key: 4, label: 'label4'},
  {key: 5, label: 'label5'},
  {key: 6, label: 'label6'},
];

我需要的是根据每个数组项的key映射翻译并返回翻译后的选项数组

const options = [
  {key: "key1", label: 'label1', translated: 'translation 1'},
  {key: "key2", label: 'label2', translated: 'translation 2'},
  {key: "key3", label: 'label3', translated: 'translation 3'},
  {key: "key4", label: 'label4', translated: 'translation 4'},
  {key: "key5", label: 'label5', translated: 'translation 5'},
  {key: "key6", label: 'label6', translated: 'translation 6'},
];

我设法使用from(options)来做到这一点,但是显然它会单独发出数组的每个成员-我需要完整的数组。在下面的代码中,我尝试压缩所有翻译,但仅收到翻译后的字符串数组-如何将它们映射回每个option

import { of, from, timer, zip } from 'rxjs';
import { map, mergeMap } from 'rxjs/operators';

const getTranslation = (key) => of('translation ' + key)

const options = [
  { key: "key1", label: 'label1' },
  { key: "key2", label: 'label2' },
  { key: "key3", label: 'label3' },
  { key: "key4", label: 'label4' },
  { key: "key5", label: 'label5' },
  { key: "key6", label: 'label6' },
];

of(options).pipe(
  mergeMap(options =>
    zip(...options.map(option =>
      getTranslation(option.key)))
  )).subscribe(console.log);

在这里我创建了playground on stackblitz

2 个答案:

答案 0 :(得分:2)

您可以将每个选项映射到一个Observable,然后forkJoin将它们全部加入:

forkJoin(options.map(options =>
  getTranslation(option.key).pipe(map(translation => ({
    ...option,
    translated: translation
  })))
)).subscribe(console.log);

答案 1 :(得分:0)

使用传播和休息(...)收集对象,然后重新传播其余对象:

zip(...options.map(({ key, ...option }) => ({ ...option, key: getTranslation(key) })))