为什么 action 不会在第二次运行时触发 Effect? [英] Why action doesn't trigger Effect the second time it runs?

问题描述

效果:

@Effect()
  loadDocsEffect$ = this.actions$.pipe(
    ofType(myActionTypes.LoadDocs),
    mergeMap(action => this.myService.getDocs()),
    map(data => new LoadDocsSuccess(data)),
    catchError(error => Observable.of(new LoadDocsFailure(error)))
  );

当我有数据返回时它工作，但是当服务器响应错误 - 例如 404 时，observable 是完整的并且不会在我第二次分派动作时触发效果.我寻找一种方法来正确处理错误并继续观察流，以便我可以在我的组件中订阅它并采取相应的行动.

It works when I have data returned, but when the server responds with an error - 404 for example, the observable is complete and doesn't trigger the effect the second time I dispatch an action. I looked for a way to handle the error properly and to continue the observable stream so I could subscribe to it in my component and act accordingly.

@ngrx Effect 中的解决方法没有第二次运行 对我不起作用，或者我无法让它起作用.

The solution in @ngrx Effect does not run the second time did not work for me, or I couldn't make it work.

推荐答案

您需要根据请求 catchError 而不是 actions$.为此，您需要按如下方式修改代码:

You need to catchError on request instead of the actions$. To do this, you will need to modify your code as following:

mergeMap(action => 
  this.myService.getDocs().pipe(
    map(data => new LoadDocsSuccess(data)),
    catchError(error => Observable.of(new LoadDocsFailure(error)))
  )
)

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