Redux重击：从已调度操作中返回承诺

Question

Redux thunk成功调度某些动作后，是否可以从动作创建者那里返回承诺/信号，并解决？

考虑以下动作创建者：

function doPost(data) {
    return (dispatch) => {
        dispatch({type: POST_LOADING});
        Source.doPost() // async http operation
            .then(response => {
                dispatch({type: POST_SUCCESS, payload: response})
            })
            .catch(errorMessage => {
                dispatch({type: POST_ERROR, payload: errorMessage})
            });
    }
}

当Redux分派POST_SUCCESS或POST_ERROR操作时，我想在调用 doPost 操作创建者后 在组件中
异步调用某些函数。一种解决方案是将回调传递给动作创建者本身，但这会使代码混乱并且难以掌握和维护。我也可以在while循环中轮询Redux状态，但是那样效率很低。
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理想情况下，解决方案是一个承诺，当调度某些操作（在这种情况下为POST_SUCCESS或POST_ERROR）时，它应该解决/拒绝。

handlerFunction {
  doPost(data)
  closeWindow()
}

上面的示例应该被重构，因此closeWindow（）仅在doPost（）成功时才被调用。

Answer 1

当然，您可以从异步操作中返回承诺：

function doPost(data) {
    return (dispatch) => {
        dispatch({type: POST_LOADING});
        // Returning promise.
        return Source.doPost() // async http operation
            .then(response => {
                dispatch({type: POST_SUCCESS, payload: response})
                // Returning response, to be able to handle it after dispatching async action.
                return response;
            })
            .catch(errorMessage => {
                dispatch({type: POST_ERROR, payload: errorMessage})
                // Throwing an error, to be able handle errors later, in component.
                throw new Error(errorMessage)
            });
    }
}

现在，dispatch函数返回了一个承诺：

handlerFunction {
  dispatch(doPost(data))
      // Now, we have access to `response` object, which we returned from promise in `doPost` action.
      .then(response => {
          // This function will be called when async action was succeeded.
          closeWindow();
      })
      .catch(() => {
          // This function will be called when async action was failed.
      });
}