使用export导出工具方法，使用export default导出对象

导出多个工具方法mousewheel方法、getRowIdentity方法(文件：util.js)

const isFirefox = navigator.userAgent.toLowerCase().indexOf('firefox') > -1;

export const mousewheel = function(element, callback) {
  if (element && element.addEventListener) {
    element.addEventListener(isFirefox ? 'DOMMouseScroll' : 'mousewheel', callback);
  }
};

export const getRowIdentity = (row, rowKey) => {
  if (!row) throw new Error('row is required when get row identity');
  if (typeof rowKey === 'string') {
    return row[rowKey];
  } else if (typeof rowKey === 'function') {
    return rowKey.call(null, row);
  }
};

导入多个工具方法mousewheel方法、getRowIdentity方法(文件：export-demo.vue)

import { mousewheel } from './util';
import { getRowIdentity } from './util';

import { orderBy, getColumnById, getRowIdentity } from './util';

导出类TableStore(文件：table-store.js)

import Vue from 'vue';
import debounce from 'throttle-debounce/debounce';
import { orderBy, getColumnById, getRowIdentity } from './util';

const sortData = (data, states) => {
  // TO DO 
};

const getKeysMap = function(array, rowKey) {
  const arrayMap = {};
  (array || []).forEach((row, index) => {
    arrayMap[getRowIdentity(row, rowKey)] = { row, index };
  });
  return arrayMap;
};

const TableStore = function(table, initialState = {}) {
  if (!table) {
    throw new Error('Table is required.');
  }
  this.table = table;

  this.states = {
    rowKey: null,
    _columns: [],
    columns: [],
    fixedColumns: [],
    rightFixedColumns: [],
    _data: null,
    filteredData: null,
    data: null,
    sortingColumn: null,
    sortProp: null,
    sortOrder: null,
    isAllSelected: false,
    selection: [],
    reserveSelection: false,
    selectable: null,
    currentRow: null,
    hoverRow: null,
    filters: {}
  };

  for (let prop in initialState) {
    if (initialState.hasOwnProperty(prop) && this.states.hasOwnProperty(prop)) {
      this.states[prop] = initialState[prop];
    }
  }
};

TableStore.prototype.isSelected = function(row) {
  // TO DO 
};

TableStore.prototype.clearSelection = function() {
  // TO DO 
};

export default TableStore;

导入类TableStore(文件：export-demo.vue)

import TableStore from './table-store';