Today, let’s start with the simplest one, rewriting an existing tab switching function into a javascript plug-in.
How to write native functions
The easiest way to rewrite a javascript method as a js plug-in is to mount this method under the window global object
Let’s first take a look at the most original code written using functions:
tab.html
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<meta name="renderer" content="webkit">
<title>jquery_hjb_tab插件demo</title>
<link rel="stylesheet" href="h.css"/>
</head>
<body>
<div id="tab">
<div class="tabs">
<ul>
<li><a href="#">tab1</a></li>
<li><a href="#">tab2</a></li>
<li><a href="#">tab3</a></li>
<li><a href="#">tab4</a></li>
</ul>
</div>
<div class="tabCons">
<section>内容一</section>
<section>内容二</section>
<section>内容三</section>
<section>内容四</section>
</div>
</div>
<script>
window.onload = h_tab('tab');
function h_tab(tabId){
var oLinks = document.getElementById(tabId).getElementsByTagName("a");
var oCons = document.getElementById(tabId).getElementsByTagName("section");
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
}
</script>h.css
@charset "utf-8";
/*
//author:hjb2722404
//description:
//date:2016/2/18
*/
.tabs ul { width: 100%; list-style-type: none;}
.tabs ul li { width: 48%; display: inline-block; margin: 0; padding: 0;}
.tabs ul li a {border-bottom: 3px solid #cccccc; width: 100%; height: 100%; display: block; text-align: center; min-height: 40px; line-height: 40px; text-decoration: none; font-family: "微软雅黑"; color: #a94442}
.tabs ul li a.cur { border-bottom: 3px solid #f26123;}
.tabCons section { display: none;}
.tabCons section:nth-child(1) { display: block;}The above two codes are basic codes, and we will improve them step by step based on this code.
Native plug-in writing method
Okay, now, let’s rewrite this method into a plug-in mounted under the window object:
tab.html
……
// 下面是第一次改动
<script type="text/javascript" src="h_tabs.js"></script>
<script>
H_tab("tab");
</script>
</body>
</html>h_tabs.js
window.H_tab = function(tabId){
var oLinks = document.getElementById(tabId).getElementsByTagName("a");
var oCons = document.getElementById(tabId).getElementsByTagName("section");
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
};However, we found that although this way of writing is very simple, it also has problems: window is a global object. If we mount all our methods under it and use it as a plug-in, when there are too many plug-ins, it is easy to create a namespace. Conflict, on the other hand, although using native js can reduce external dependence, the amount of code is still relatively large and the writing method is relatively cumbersome.
jquery writing method
We try to introduce the jquery library and rewrite this plug-in into a jquery plug-in.
The jquery plug-in has three forms: class-level form, object-level form, and jquery UI component form
How to write jquery class-level plug-ins – single method
Let’s first look at the form of class-level plug-ins.
In the form of the first category-level plug-in, this method is directly mounted to the root space of jquery as a tool method:
tab.html
……
<script src="../jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="h_tabs.js"></script>
<script>
$.h_tab('tab');
</script>
</body>
</html>h_tabs.js
$.h_tab = function(tabId){
var oLinks = document.getElementById(tabId).getElementsByTagName("a");
var oCons = document.getElementById(tabId).getElementsByTagName("section");
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
};How to write jquery class-level plug-ins - multiple methods
If you want to bind multiple methods to the jquery root space, then write like this:
tab.html
……
<script src="../jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="h_tabs.js"></script>
<script>
$.h_tab('tab');
$.h_hello('hjb');
</script>
</body>
</html>h_tabs.js
$.extend({
h_tab:function(tabId){
var oLinks = document.getElementById(tabId).getElementsByTagName("a");
var oCons = document.getElementById(tabId).getElementsByTagName("section");
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
},
h_hello :function(name){
console.log("hello,",name);
}
});Although it is simple and trouble-free to use the $.extend() tool method to mount your own functions directly into the jquery root namespace, unfortunately, this method cannot take advantage of jquery’s powerful sizzle engine, that is, This method cannot be applied to the DOM element you selected.
So we need to use the object-level plug-in development method.
How to write jquery object level plug-in
The object-level plug-in development method is to use the $.fn.extend() method to bind its own method to the jquery prototype, so that all jquery object teams can apply this method to perform corresponding operations
The code is as follows:
tab.html
……
<script src="../jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="h_tabs.js"></script>
<script>
//对象级别的插件引用方法，注意和上面类级别插件的写法上的区分
$('#tab').h_tab('tab');
</script>
</body>
</html>h_tabs.js
(function($){
$.fn.extend({
h_tab:function(tabId){
var oLinks = document.getElementById(tabId).getElementsByTagName('a');
var oCons = document.getElementById(tabId).getElementsByTagName('section');
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
}
});
})(jQuery);Here, we use a closure to encapsulate the plug-in to avoid namespace pollution
Here, there are still some problems, that is, our method must pass parameters before it can be run. This causes us to use $('#tab') to select the div with the id of tab when calling, and then in the plug-in we The element is obtained again based on the passed in ID.
Now that we have used jquery’s selector, we can introduce this to solve the redundant problem of repeatedly obtaining elements.
jquery object level plug-in writing method - introduce this
tab.html
……
<script src="../jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="h_tabs.js"></script>
<script>
$('#tab').h_tab();
</script>
</body>
</html>h_tabs.js
(function($){
$.fn.extend({
h_tab:function(){
//在这里引入this
var oLinks = this.find('a');
var oCons = this.find('section');
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
this.className="cur";
oCons[this.index].style.display ="block";
}
}
}
});
})(jQuery);What needs to be noted here is that the element object we call the plug-in is ('tab'), so using this.find() directly at this time is equivalent to ('tab').find(), not $ (this).find(), pay attention to using the substitution method to distinguish the difference between the two writing methods.
As a plug-in, it should be controllable by developers, so it should also provide users with some configuration interfaces.
jquery object level plug-in writing method - adding configuration items
tab.html
……
<ul>
<!--对照文章开始的代码， 注意这里的改动 -->
<li><a href="#" class="current">tab1</a></li>
<li><a href="#">tab2</a></li>
……
<script src="../jquery.js" type="text/javascript"></script>
<script type="text/javascript" src="h_tabs.js"></script>
<script>
$('#tab').h_tab({
//使得当前选项卡标签的样式名称可自定义的配置
curName:'current'
});
</script>
</body>
</html>We changed the initial "current tab label style class name" from "cur" to "current" and passed it into the plug-in as a configuration item
h.css
.tabs ul { width: 100%; list-style-type: none;}
.tabs ul li { width: 48%; display: inline-block; margin: 0; padding: 0;}
.tabs ul li a {border-bottom: 3px solid #cccccc; width: 100%; height: 100%; display: block; text-align: center; min-height: 40px; line-height: 40px; text-decoration: none; font-family: "微软雅黑"; color: #a94442}
/*注意下面一行与之前的样式代码的对比变化之处*/
.tabs ul li a.current { border-bottom: 3px solid #f26123;}
.tabCons section { display: none;}
.tabCons section:nth-child(1) { display: block;}We have made corresponding changes in the stylesheet.
h_tabs.js
(function($){
$.fn.extend({
//给方法传入一个对象作为参数
h_tab:function(opts){
//定义默认的配置
var defaults ={
curName : 'cur'
};
//将传入的参数覆盖默认参数中的默认项，最终合并到一个新的参数对象上
var Opt = $.extend({},defaults,opts);
var oLinks = this.find('a');
var oCons = this.find('section');
for(var i = 0; i<oLinks.length; i++){
oLinks[i].index = i;
oLinks[i].onclick = function () {
for(var j =0; j<oLinks.length; j++){
oLinks[j].className="";
oCons[j].style.display = "none";
}
//在这里使用配置项的值
this.className = Opt['curName'];
oCons[this.index].style.display ="block";
}
}
}
});
})(jQuery);Here we use the merge object function of jquery's $.extend() method to overwrite the default configuration items with the configuration items passed in by the user and finally merge them into a new configuration item for use by subsequent programs.
The above is the JavaScript tab plug-in example code introduced by the editor. I hope it will be helpful to everyone!
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