常用工具类方法总结

from: https://submara.com/posts/utils/

存储localStorage

export const setStorage = (name, content) => { 
 if (!name) return;  
 if (content) {    
		 content = JSON.stringify(content);  
 }  
 window.localStorage.setItem(name, content);
};

获取localStorage

export const getStorage = name => {
  if (!name) return;  
  const data = window.localStorage.getItem(name);  
  if (data) {    
	  return JSON.parse(data);  
	} else {
	    return null;  
	}
};

删除localStorage

export const removeStorage = name => {
  if (!name) return;  
  window.localStorage.removeItem(name);
};

存储sessionStorage

export const setSessionStorage = (name, content) => {
  if (!name) return;  
  if (content) {    
	  content = JSON.stringify(content);  
	}  
	window.sessionStorage.setItem(name, content);
};

获取sessionStorage#

export const getSessionStorage = name => {
  if (!name) return;  
  return JSON.parse(window.sessionStorage.getItem(name));
};

删除sessionStorage

export const removeSessionStorage = name => {
  if (!name) return;  
  window.sessionStorage.removeItem(name);
};

下载文件

/** @param {String} path - 下载地址/下载请求地址。
*** @param {String} name - 下载文件的名字（考虑到兼容性问题，最好加上后缀名）*/
export const downloadFile = (path) => {
  const xhr = new XMLHttpRequest();  
  let fileType = path.substring(path.lastIndexOf('/') + 1);  
  xhr.open('get', path);  
  xhr.responseType = 'blob';  
  xhr.send();  
  xhr.onload = function () {
      if (this.status === 200 || this.status === 304) {
            const fileReader = new FileReader();
            fileReader.readAsDataURL(this.response);      
            fileReader.onload = function () {
                    const a = document.createElement('a');        
                    a.style.display = 'none';        
                    a.href = this.result;        
                    a.download = `${fileType}`;        
                    document.body.appendChild(a);        
                    a.click();        
                    document.body.removeChild(a);      
             };    
        }  
   };
};

文件大小格式化

export const formatFileSize = (bytes, decimalPoint = 2) => {
  if (bytes === 0) return '0 Bytes';  
  const k = 1000;  
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];  
  const i = Math.floor(Math.log(bytes) / Math.log(k));  
  return parseFloat((bytes / Math.pow(k, i)).toFixed(decimalPoint)) + ' ' + sizes[i];};

生成随机长度的字符串#

export const randomString = (len = 20) => {
  const chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz123456789';  
  const strLen = chars.length;  
  let randomStr = '';  
  for (let i = 0; i < len; i++) {
      randomStr += chars.charAt(Math.floor(Math.random() * strLen));  
  }  
  return randomStr;};

解析url地址参数

/** @param url* @param key*/
export const getUrlParams = (url, key) => {
  if (!url) return;  
  const params = (url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(
    (a, v) => ((a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a),
    {},);  
  if (key) {
      if (params[key]) {
            return params[key];    
      } else {
            return null;    
      }  
  } else {
      return params;  
  }
};

复制字符串到剪贴板

export const copyToClipboard = str => {
  const el = document.createElement('textarea');  
  el.value = str;  
  el.setAttribute('readonly', '');  
  el.style.position = 'absolute';  
  el.style.left = '-9999px';  
  document.body.appendChild(el);  
  const selected = document.getSelection().rangeCount > 0 ? 
                   document.getSelection().getRangeAt(0) : false;  el.select();  
  document.execCommand('copy');  
  document.body.removeChild(el);  
  if (selected) {
      document.getSelection().removeAllRanges();    
      document.getSelection().addRange(selected);  
  }
};

格式化时间戳

/*** timestamp 当前时间戳，毫秒* format 时间格式(例如：YYYY-MM-DD hh:mm:ss)：*/
export const dateFormat = (timestamp, format) => {
  if (!timestamp) return;  let date = new Date(timestamp);  
  let o = {    "M+": date.getMonth() + 1, //月    "D+": date.getDate(), //天    "W": "日一二三四五六".charAt(date.getDay()), //星期    "h+": date.getHours(), //时    "m+": date.getMinutes(), //分    "s+": date.getSeconds(), //秒    "q+": Math.floor((date.getMonth() + 3) / 3), //季节    "S": date.getMilliseconds() //毫秒  };  
  if (/(Y+)/.test(format)) {
      format = format.replace(RegExp.$1, (date.getFullYear() + "").substr(4 - RegExp.$1.length));  }  
  for (let k in o) {
      if (new RegExp("(" + k + ")").test(format)) {
            format = format.replace(RegExp.$1, RegExp.$1.length === 1 ? 
            o[k] : ("00" + o[k]).substr(("" + o[k]).length));
      }  
  }  
  return format;};

格式化时间（源数据单位 s）

export const formatDateHms = (date = 0, format = '') => {
  const hours = Math.floor(date / 3600).toString().padStart(2, '0');  
  const minute = Math.floor((date / 60) % 60).toString().padStart(2, '0');  
  const second = Math.floor(date % 60)  .toString()  .padStart(2, '0');  if (format === 'cn') {    return `${hours}时${minute}分${second}秒`;  } else {    return `${hours}:${minute}:${second}`;  }};