FileUpload.js

var getError = function (options, xhr) {
  var msg = 'cannot post ' + options.url + ":" + xhr.status;
  var err = new Error(msg);
  err.status = xhr.status;
  err.method = 'post';
  err.url = options.url;
  return err;
}
var getBody = function (xhr) {
  var text = xhr.responseText || xhr.response;
  if (!text) {
    return text;
  }

  try {
    return JSON.parse(text);
  } catch (e) {
    return text;
  }
}
var Uploader = {
  post: function (options) {
    if (typeof XMLHttpRequest === 'undefined') {
      return;
    }

    var xhr = new XMLHttpRequest();
    if (xhr.upload) {
      xhr.upload.onprogress = function (e) {
        if (e.total > 0) {
          e.percent = e.loaded / e.total * 100;
        }
        options.onLoad(e);
      }
    }
    var formData = new FormData();

    if (options.data) {
      for (var i in options.data) {
        formData.append(i, options.data[i]);
      }
    }
    formData.append(options.filename, options.file);

    xhr.onerror = function (e) {
      options.onEnd(e);
      options.onError(e);
    }
    xhr.onload = function (e) {
      if (xhr.status !== 200) {
        options.onEnd(e);
        return options.onError(getError(options, xhr), getBody(xhr));
      }
      options.onEnd(e);
      options.onSuccess(getBody(xhr));
    }

    xhr.open('post', options.url, true);
    xhr.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
    if (options.header) {
      for (var i in options.header) {
        xhr.setRequestHeader(i, options.header[i]);
      }
    }
    xhr.send(formData);
  }
}

module.exports = {
  uploadFile: function (options) {
    options.url = options.url || "/upload";
    options.filename = options.filename || "file";
    options.beforeUpload = options.beforeUpload || function (e) { return true; };
    options.onSuccess = options.onSuccess || function (e) { };
    options.onError = options.onError || function (e) { };
    options.onLoad = options.onLoad || function (e) { };
    options.onStart = options.onStart || function (e) { };
    options.onEnd = options.onEnd || function (e) { };

    if (options.beforeUpload(options)) {
      options.onStart(options);
      // 开始上传文件
      Uploader.post(options);
    }
  },
  uploadFiles: function (options) {

  }
}