本文介绍了TypeError:返回未知类型的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在使用 ngrx/effects .我收到此错误:
I am using ngrx/effects. I got this error:
这是我的代码的一部分:
This is part of my codes:
this.store.dispatch({ type: CHAT_LOAD_MESSAGES, payload: chatId });
@Effect() loadMessages$ = this.updates$
.whenAction(CHAT_LOAD_MESSAGES)
.map<string>(toPayload)
.do(chatId => console.log('chatId', chatId)) // Here I can get chatId
.switchMapTo(chatId => this.chatService.loadMessages(chatId)) // The error comes out because of this line
.do(res => console.log('res', res)) // This didn't run
.map((messages: Message[]) => ({ type: CHAT_LOAD_MESSAGES_SUCCESS, payload: messages }));
loadMessages(chatId: string): Observable<Message[]> {
// This is what I am using to test right now.
// Maybe this line is wrong? How can I write correct simulation?
return Observable.of([{ id:1, content:'Hi' });
}
这可能是什么原因造成的?谢谢
What may cause this? Thanks
推荐答案
感谢@apreg指出了我在Gitter上的错误.
Thanks for @apreg point out my error on Gitter.
我应该将switchMapTo
更改为switchMap
.
switchMap 和 switchMapTo .
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