使用Redux-Thunk / Axios从onUploadProgress事件调度操作

Question

以下代码可以正常上传文件，并且可以按预期成功响应或失败，但是，我无法弄清楚如何从onUploadProgress事件中调度我的uploadFileProgress操作。 我可以console.log进度/百分比，当我尝试将分派包装在IIFE中时，触发分派不是函数错误。 希望这是我所缺少的一个小问题。 提前致谢！

export function uploadFile(values, callback = () => {}) {
  const uploadFileData = new FormData();
  uploadFileData.append('fileName', values.fileName);
  uploadFileData.append('file', values.file);
  uploadFileData.append('file', {
    filename: values.filename,
    contentType: values.contentType,
  });
  const uploadProgress = {
    onUploadProgress: (ProgressEvent) => {
      let progressData = 0;
      const totalLength = ProgressEvent.lengthComputable ? ProgressEvent.total : ProgressEvent.target.getResponseHeader('content-length') || ProgressEvent.target.getResponseHeader('x-decompressed-content-length');
      if (totalLength !== null) {
        progressData = Math.round((ProgressEvent.loaded * 100) / totalLength);
      }
      return function action(dispatch) {
        dispatch(uploadFileUpload(progressData));
      };
    },
  };
  const configPlusProgress = Object.assign(uploadProgress, config);
  const request = () => axios.post(myURL, uploadFileData, configPlusProgress);
  return function action(dispatch) {
    dispatch(uploadFileLoading(true));
    return request()
      .then((response) => {
        if (response.status !== 201) {
          dispatch(uploadFileFail());
          throw Error(response.statusText);
        }
        dispatch(uploadFileLoading(false));
        return response;
      })
      .then(response => dispatch(uploadFileSuccess(response)))
      .then(() => callback())
      .catch(err => dispatch(uploadFileFail(err)));
  };
}

Answer 1

将您的请求配置移到返回的函数中（可以使用dispatch函数）：

export function uploadFile(values, callback = () => {}) {
  const uploadFileData = new FormData();
  uploadFileData.append('fileName', values.fileName);
  uploadFileData.append('file', values.file);
  uploadFileData.append('file', {
    filename: values.filename,
    contentType: values.contentType,
  });
  return function action(dispatch) {
    const uploadProgress = {
      onUploadProgress: (ProgressEvent) => {
        let progressData = 0;
        const totalLength = ProgressEvent.lengthComputable ? ProgressEvent.total : ProgressEvent.target.getResponseHeader('content-length') || ProgressEvent.target.getResponseHeader('x-decompressed-content-length');
        if (totalLength !== null) {
          progressData = Math.round((ProgressEvent.loaded * 100) / totalLength);
        }

        dispatch(uploadFileUpload(progressData));
      },
    };
    const configPlusProgress = Object.assign(uploadProgress, config);
    const request = () => axios.post(myURL, uploadFileData, configPlusProgress);

    dispatch(uploadFileLoading(true));
    return request()
      .then((response) => {
        if (response.status !== 201) {
          dispatch(uploadFileFail());
          throw Error(response.statusText);
        }
        dispatch(uploadFileLoading(false));
        return response;
      })
      .then(response => dispatch(uploadFileSuccess(response)))
      .then(() => callback())
      .catch(err => dispatch(uploadFileFail(err)));
  };
}

同样， onUploadProgress应该只是抓取上传进度事件。

Answer 2

我无法完全解决您的代码，但这是redux-thunk的基本功能，它可以做异步工作并使用动作。

const doSomeAsyncStuff = () =>
    async ( dispatch ) => {
         try {
             const response = await someAsyncStuff();
             return dispatch( someSuccessAction( response.data );
         } catch ( error ) {
             return dispatch( someFailureAction( err );
         }
    }

当然，必须将redux-thunk作为中间件添加。

Answer 3

你为什么要从onUploadProgress函数返回一个函数

return function action(dispatch) {
    dispatch(uploadFileUpload(progressData));
  };

除此之外，您可以

dispatch(uploadFileUpload(progressData));