js 一些小技巧 2

ajs 的一些小技巧

(1)傳入一個表單控件(如input輸入框,按鈕)擷取所在的form

var getform= function (formelement) {

var $that=$(formelement).parent();

var max=6;//limit the depth

var fieldsetelement=null;//form element

var tagname=null;//html tag name

while((fieldsetelement=$that.get(0))&&fieldsetelement.tagname!==undefined&&(tagname=fieldsetelement.tagname.tolowercase())!=='form'&&max>0){

if(tagname==='fieldset'){//html5 new tag

$that=$(fieldsetelement.form);

break;

}

$that=$that.parent();

max--;

}

console.log(max);

return $that;

};

完整示例:

<!doctype html>

<html>

var getform = function (formelement) {

var $that = $(formelement).parent();

var max = 6;//limit the depth

var fieldsetelement = null;//form element

var tagname = null;//html tag name

while ((fieldsetelement = $that.get(0)) && fieldsetelement.tagname !== undefined && (tagname = fieldsetelement.tagname.tolowercase()) !== 'form' && max > 0) {

if (tagname === 'fieldset') {//html5 new tag

$that = $(fieldsetelement.form);

break;

}

$that = $that.parent();

max--;

}

console.log(max);

return $that;

};

var getform22 = function (self) {

$form = getform(self);

console.log($form);

}

</script>

</head>

<body>

<div>

<input id="username" type="text" name="username" placeholder="使用者名"

required>

<input id="password" type="password" name="password" placeholder="密碼"

</div>

<div>

<input type="button" id="submit" onclick="getform22(this)"

value="登入">

</div>

</form>

</div>

</body>

</html>

(2)js把毫秒轉化為時間

var releasedate=new date(number(obj.releasetime)*1000).format('mm-dd hh:mm');//把毫秒數轉化為日期

注意:上述代碼中obj.releasetime的機關是秒(不是毫秒)

(3)把數組拼接為字元串:使用join

var html = [];

if(data.length2>0){

var recordlist=data.recordlist;

for(var i=0;i<data.length2;i++){

html.push(getbbscommentlistitem(recordlist[i]));

$livespanel_ul.append(html.join(''));

}

(4)web app中使用jsonp跨域請求時如何帶上sessionid

跨域通路

在url位址最後面加上;jsessionid=<你的實際sessionid>

執行個體

var modi_url='http://'+server_url+'/user/mod_pass?callback=?&password='+old_password_val+"&password2="+new_password_val+";jsessionid="+window.sessionid;

console.log&&console.log(modi_url);

$.jsonp({url:modi_url,success:function(data){

var result=data.result;

hidemask2();

switch (result)

{

case 1:

user.password=new_password_val;

alert("修改成功");

$.ui.goback();

break;

case 23:

alert("新密碼不能為空");

case 21:

alert("請先登入");

case 22:

alert("兩次密碼不能相同");

case 24:

alert("密碼已過期,請點選右上角的重新整理按鈕");

}});

(5)建立數組

(6)判斷對象是否包含指定屬性

'length' in objarr 可以判斷objarr 是否包含length屬性

示例:

if (!('length' in objarr)) {// just only single component (not array).

objarr.style.display = "block";

}else{

for ( var i = 0; i < objarr.length; i++) {

var objone = objarr[i];

objone.style.display = "block";

}

(7)擷取浏覽器類型

jquery-1.11.1.js中沒有了擷取浏覽器的方法,可以添加如下代碼

/***

* get browser type

* @param jquery

var checkbrowser = function (jquery) {

if (jquery.browser) return;

jquery.browser = {};

jquery.browser.mozilla = false;

jquery.browser.webkit = false;

jquery.browser.opera = false;

jquery.browser.msie = false;

var nagt = navigator.useragent;

jquery.browser.name = navigator.appname;

jquery.browser.fullversion = '' + parsefloat(navigator.appversion);

jquery.browser.majorversion = parseint(navigator.appversion, 10);

var nameoffset, veroffset, ix;

// in opera, the true version is after "opera" or after "version"

if ((veroffset = nagt.indexof("opera")) != -1) {

jquery.browser.opera = true;

jquery.browser.name = "opera";

jquery.browser.fullversion = nagt.substring(veroffset + 6);

if ((veroffset = nagt.indexof("version")) != -1)

jquery.browser.fullversion = nagt.substring(veroffset + 8);

// in msie, the true version is after "msie" in useragent

else if ((veroffset = nagt.indexof("msie")) != -1) {

jquery.browser.msie = true;

jquery.browser.name = "microsoft internet explorer";

jquery.browser.fullversion = nagt.substring(veroffset + 5);

// in chrome, the true version is after "chrome"

else if ((veroffset = nagt.indexof("chrome")) != -1) {

jquery.browser.webkit = true;

jquery.browser.name = "chrome";

jquery.browser.fullversion = nagt.substring(veroffset + 7);

// in safari, the true version is after "safari" or after "version"

else if ((veroffset = nagt.indexof("safari")) != -1) {

jquery.browser.name = "safari";

// in firefox, the true version is after "firefox"

else if ((veroffset = nagt.indexof("firefox")) != -1) {

jquery.browser.mozilla = true;

jquery.browser.name = "firefox";

jquery.browser.fullversion = nagt.substring(veroffset + 8);

// in most other browsers, "name/version" is at the end of useragent

else if ((nameoffset = nagt.lastindexof(' ') + 1) <

(veroffset = nagt.lastindexof('/'))) {

jquery.browser.name = nagt.substring(nameoffset, veroffset);

jquery.browser.fullversion = nagt.substring(veroffset + 1);

if (jquery.browser.name.tolowercase() == jquery.browser.name.touppercase()) {

jquery.browser.name = navigator.appname;

// trim the fullversion string at semicolon/space if present

if ((ix = jquery.browser.fullversion.indexof(";")) != -1)

jquery.browser.fullversion = jquery.browser.fullversion.substring(0, ix);

if ((ix = jquery.browser.fullversion.indexof(" ")) != -1)

jquery.browser.majorversion = parseint('' + jquery.browser.fullversion, 10);

if (isnan(jquery.browser.majorversion)) {

jquery.browser.fullversion = '' + parsefloat(navigator.appversion);

jquery.browser.majorversion = parseint(navigator.appversion, 10);

jquery.browser.version = jquery.browser.majorversion;

};

checkbrowser(jquery);

以上用于jquery.

下面的不是用于jquery的 :

* get browser type and browser version and language

when page open,the function will be executed automaticly

* @param write22

* @returns {{systemlanguage,userlanguage,ver}}

com.whuang.hsj.getbrowserversion=(function(write22){

var browser = {};

// console.dir(navigator);

var useragent = navigator.useragent.tolowercase();

/*for(osvid in navigator){

var value222=navigator[osvid];

document.writeln(osvid+":&nbsp;"+value222+'<br>');

}*/

var lang22=navigator.language;

// document.writeln(useragent+'<br>');

// document.writeln(navigator.appcodename+'<br>');

var s;

(s = useragent.match(/msie ([\d.]+)/)) ? browser.ie = s[1] : (s = useragent.match(/firefox\/([\d.]+)/)) ? browser.firefox = s[1] : (s = useragent.match(/chrome\/([\d.]+)/)) ? browser.chrome = s[1] :

(s = useragent.match(/opera.([\d.]+)/)) ? browser.opera = s[1] : (s = useragent.match(/version\/([\d.]+).*safari/)) ? browser.safari = s[1] : 0;

var version = "";

if (browser.ie) {

version = browser.ie;

if(write22 && write22!=false && write22!='false'){

document.writeln('ie<br>');

if(!browser.lang ||browser.lang==undefined){

lang22=navigator.browserlanguage;

browser.systemlanguage=navigator.systemlanguage ;

browser.userlanguage=navigator.userlanguage;

else

if (browser.firefox) {

version = browser.firefox;

browser.mozilla=browser.firefox;

document.writeln('firefox<br>');

if (browser.chrome) {

version = browser.chrome;

document.writeln('chrome<br>');

if (browser.opera) {

version = browser.opera;

document.writeln('opera<br>');

if (browser.safari) {

version = browser.safari;

document.writeln('safari<br>');

else {

version = 'unknown browser';

browser.ver=version;

if(lang22 && lang22!=undefined)

{

browser.lang=lang22.tolowercase();

return browser;

})();

使用方法:

var brow ;

if(com.whuang.hsj.getbrowserversion){

brow =com.whuang.hsj.getbrowserversion;

if(type22=='mid'||type22=='middle'){

$("#loadpanel").css("background-image", "url(\"../static/images/loading/loading_middle.gif\")");

if(brow&&brow.chrome){//因為在chrome 中有時背景圖檔gif不顯示

$("#loading_gif").css("display","block");

$("#loading_gif").attr("src", "../static/images/loading/loading_middle.gif");

}else if(type22=='small'||type22=='little'){

$("#loadpanel").css("background-image", "url(\"../static/images/loading/loading_small.gif\")");

$("#loading_gif").attr("src", "../static/images/loading/loading_small.gif");

}else{

$("#loadpanel").css("background-image", "url(\""+type22+"\")");

(8)通過name屬性擷取單個元素

* if is radio ,please use com.whuang.hsj.$$arr

* @param name22

* @returns

com.whuang.hsj.$$one = function(name22) {

if (com.whuang.hsj.ishasvalue(name22)) {

var names222=document.getelementsbyname(name22);

//alert("names222:"+names222);

//alert("typeof:"+(typeof names222 ));

var classname=object.prototype.tostring.call(names222);

var boolean_isarray;

var iehtmlcollection='[object htmlcollection]';

if(isietest)//if browser is ie

boolean_isarray=( classname=== '[object object]') ||(classname=== iehtmlcollection) ||names222 instanceof array ;

}else

boolean_isarray=( classname=== '[object array]') ||(classname=== '[object nodelist]' )||(classname==iehtmlcollection)||names222 instanceof array||names222 instanceof nodelist;

if(names222){

if(boolean_isarray){

return names222[0];

}else{

return names222;

return "";

} else {

return "";

使用場景:

html代碼:

<input id="username" type="text" name="username" placeholder="使用者名"

js代碼

var username=com.whuang.hsj.$$one("username");

alert(username.value);

(9)字元串source 中是否包含key2

com.whuang.hsj.contains=function(source,key2){

var isdownload=(source.indexof(key2)>-1);

if(isdownload){

return true;

return false;

}

(10)判斷以指定字元串開頭或結尾

com.whuang.hsj.startwith=function(str,regex){

if(regex==undefined||str==undefined){

return str.indexof(regex)==0;

com.whuang.hsj.endwith=function(str,regex){

return str.lastindexof(regex)==str.length-regex.length;

js 一些小技巧 2

繼續閱讀

EGORefreshTableHeaderView 解讀代碼解讀 ELTableViewController 的使用寫在最後

請求逾時VUE axios重新再次請求

今日頭條iOS用戶端啟動速度優化技術調研實測資料

nodejs微信開發---授權登入+擷取使用者資訊微信網頁授權

debian9更新4.9.0核心到4.19.2核心過程

Javascript建構Bingo卡片遊戲

JavaScript的那些坑之事件代理事件代理事件階段

javascript的for (var i in data)慎用javascript中的for (var i in data)謹慎用

tab滑鼠經過菜單切換

vue （vue2.0）使用總結(從大體結構總結)

vue搭建過程及出現問題

/\B(?=(?:\d{3})+$)/g 一條令人費解的正規表達式

适用于JavaScript的ECMAScript 2020規範向前發展

JS生成uuid的四種方法

layui多任務上傳添加進度條