在using mergMap之后不能访问以前的Payload值

Question

我有以下代码:

export const googleTagManagerInternalActionsEpic: Epic<RootAction, RootAction, RootState, Services> = (action$, state$) => {
return action$.pipe(
mergeMap(action => merge(
of(action).pipe(
filter(isActionOf(triggerGTMEvent)),
tap(({ payload: eventName }) => {
console.log(eventName);
}),
mergeMap(() => loadQuestion()),
map(questionImport => questionImport.default),
tap((question) => {
console.log(question);
debugger;
}),
ignoreElements(),
),
)),
);
}

我需要在第二个console.log(...)上访问与第一个console.log(...)上相同的eventName值。我这里的问题是我之间的mergeMap(这是防止有效载荷的传播)。为了从loadQuestion()调用中获得一些信息，我被迫使用mergeMap。

是否有办法让我得到两个值?

谢谢!

Answer 1

您可以使用第二个参数在mergeMap:

...
tap(({ payload: eventName }) => {
console.log(eventName);
}),
mergeMap(() => loadQuestion(), (eventName, questionImport) => ({
eventName,
questionImport
})),
map(({ eventName, questionImport }) => ({
eventName,
question: questionImport.default
})),
tap(({ eventName, question }) => {
console.log(eventName, question);
debugger;
}),
...