[英]How to make redux-observable send multiple actions before and after ajax request?
我正在嘗試為redux-observable編寫Epic。 但是我有一個問題(
在執行.map(response => formSavedAction(response))
之前執行ON_EMPTY_FORM_STATE
操作。
我該如何解決? 基本上我想要得到的是:
FORM_SEND
操作 formSavedAction(response)
{ type: ON_FORM_SUBMIT_ERROR }
{ type: EMPTY_FORM_STATE }
這是我的代碼:
const saveProductEpic = (action$, $store) =>
action$.ofType(SUBMIT_FORM)
.mergeMap(action => ajax.post('http://localhost:9000/products', action.payload,
{ 'Content-Type': 'application/json' }))
.map(response => formSavedAction(response))
.catch(err => { $store.dispatch({ type: ON_FORM_SUBMIT_ERROR }) })
.do(() => { $store.dispatch({ type: EMPTY_FORM_STATE }) })
問題是,在AJAX請求之前而不是在AJAX請求之后調度了動作{ type: EMPTY_FORM_STATE }
。
有沒有什么辦法解決這一問題?
redux-observable的工作方式是在中間件中預訂由epic函數返回的observable。 您的可觀察對象必須發出redux操作,因為訂閱函數只是: action => store.dispatch(action)
因為您直接在史詩中使用store.dispatch,所以您繞過了redux可觀察的問題,並按期望的順序進行了調度。
要按照期望的順序發出操作,可以執行以下操作:
action$.ofType(SUBMIT_FORM)
.mergeMap(action => ajax.post('http://localhost:9000/products', action.payload,
{ 'Content-Type': 'application/json' }))
.map(response => formSavedAction(response))
// Notice that catch is now returning the value by dropping the brackets.
.catch(err => Observable.of({ type: ON_FORM_SUBMIT_ERROR }))
// send whatever action has come through, and add the empty state action after it.
.mergeMap(action => Observable.of(action, { type: EMPTY_FORM_STATE }))
const saveProductEpic = (action$, $store) => action$.ofType(SUBMIT_FORM)
.mergeMap((data) => Rx.Observable.concat(
ajax.post(url, data.payload, params).mergeMap(
(response) => Rx.Observable.of(formSavedAction(response)) )
.catch(err => { $store.dispatch({ type: ON_FORM_SUBMIT_ERROR }) }),
Rx.Observable.of({ type: ON_EMPTY_FORM_STATE })
.delay(2000)
));
const saveProductEpic = (action$, $store) => action$.ofType(SUBMIT_FORM) .mergeMap(action => ajax.post('http://localhost:9000/products',action.payload, { 'Content-Type': 'application/json' }) .mergeMap(response => Observable.of(formSavedAction(response), emptyFormStateAction())) .catch(err => Observable.of( formSubmitErrorAction(), emptyFormStateAction()) ) );
其中emptyFormStateAction和formSubmitErrorAction是動作創建者。
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