rxjs - Redux Observables/RxJS : How to make epic that returns different actions based on if/else?

Question

我正在尝试使用以下方法将我的应用与应用内购买 Hook :https://github.com/chirag04/react-native-in-app-utils

我有一个史诗，如果成功，我想发出成功，如果失败，我想发出失败。像这样的东西:

import 'rxjs';
import { InAppUtils } from 'NativeModules';

import * as packagesActions from '../ducks/packages';
import * as subscriptionActions from '../ducks/subscription';

export default function createSubscription(action$, store) {
  return action$.ofType(packagesActions.SELECT)
    .mergeMap(action => {
      const productId = action.payload;
      InAppUtils.purchaseProduct(productId, (error, response) => {
        if(response && response.productIdentifier) {
          return subscriptionActions.subscribeSuccess();
        } else {
          return subscriptionActions.subscribeFailure();
        }
      });
    });
};

但是我不知道如何写 mergeMap的内容.有没有办法做到这一点？

Answer 1

InAppUtils.purchaseProduct似乎使用 Node 风格的回调。有一个 RxJS 静态方法可用于从这样的 API 调用中创建可观察对象: bindNodeCallback .

在您的 mergeMap 内，你应该能够做这样的事情

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/bindNodeCallback';
import 'rxjs/add/observable/of';

...
.mergeMap(action => {
  const productId = action.payload;
  const bound = Observable.bindNodeCallback((callback) => InAppUtils.purchaseProduct(productId, callback));
  return bound()
    .map(response => subscriptionActions.subscribeSuccess())
    .catch(error => Observable.of(subscriptionActions.subscribeFailure()));
});