Detailed explanation of jQuery plug-in development methods

jQuery plug-in development

Generally speaking, the development of jQuery plug-ins is divided into two types: one is the global function hanging under the jQuery namespace, which can also be called a static method; the other is the jQuery object level method, that is A method that is hung under the jQuery prototype so that jQuery object instances obtained through the selector can also share this method.

1. jQuery extension

　1. $.extend(object)

　 Similar to the .Net extension method, used to extend jQuery. Then you can call it using $..

$(function(){
$.extend({ fun1: function () { alert("为jQuery扩展一个fun1函数!"); } });
$.fun1();
})

　 2. $.fn.extend(object)

Extend jQuery object.

$.fn.extend({ fun2: function () { alert("执行方法2"); } });
$("#id1").fun2();

You can use google to see:

The above writing is equivalent to:

$.fn.fun2 = function () { alert("执行方法2"); }
$(this).fun2();

2. Private domain

It is defined as follows:

(function ($) { })(jQuery);
//相当于
var fn = function (xxoo) { };
fn(jQuery);

The following code pops up 123.

$(function(){
var fn = function (xxoo) { };
fn(alert(123));
})

3. Basic steps to define a plug-in

1. Define the scope

When developing a jQuery plug-in, you must first isolate the plug-in code from the outside world. External code is not allowed to directly access the internal content of the plug-in. Code, the code inside the plug-in does not affect the outside.

//Step 1 Define the plug-in private scope

(function ($) {
 
})(jQuery);

This will ensure that the code inside the plug-in is isolated from the outside world.

　2. Extend jQuery

After defining the scope, in order to allow external calls, you need to extend the plug-in to jQuery.

//步骤1 定义私有作用域
 (function ($) {
 //步骤2 插件的扩展方法名称
 $.fn.MyFrame = function (options) {
   
 }
 })(jQuery);

3. Default value

After defining the jQuery plug-in, if you want some parameters to have default values, you can specify them in this way.

//步骤1 定义私有作用域
 (function ($) {
 //步骤3 插件的默认值属性
 var defaults = {
  Id: '#id1',
 };
 //步骤2 插件的扩展方法名称
 $.fn.MyFrame = function (options) {
  //步骤3 合并用户自定义属性，默认属性(如果options为空，则使用defaults)
  var options = $.extend(defaults, options);
 }
 })(jQuery);

4. Support jQuery selector

//步骤1 定义私有作用域
(function ($) {
//步骤3 插件的默认值属性
var defaults = {
 Id: '#id1',
};
//步骤2 插件的扩展方法名称
$.fn.MyFrame = function (options) {
 //步骤3 合并用户自定义属性，默认属性(如果options为空，则使用defaults)
 var options = $.extend(defaults, options);
}
//步骤4 支持jQuery选择器
this.each(function () {
 
});
})(jQuery);

5. Support jQuery chain call

//步骤1 定义私有作用域
 (function ($) {
 //步骤3 插件的默认值属性
 var defaults = {
  Id: '#id1',
 };
 //步骤2 插件的扩展方法名称
 $.fn.MyFrame = function (options) {
  //步骤3 合并用户自定义属性，默认属性(如果options为空，则使用defaults)
  var options = $.extend(defaults, options);
 }
 //步骤4 支持jQuery选择器
 //步骤5 支持链式调用(将步骤4返回)
 return this.each(function () {
 
 });
 })(jQuery);

6. Plug-in internal methods

//步骤1 定义私有作用域
(function ($) {
//步骤3 插件的默认值属性
var defaults = {
 Id: '#id1',
};
 
//步骤6 在插件里定义函数
var MyFun = function (obj) {
 alert(obj);
}
 
//步骤2 插件的扩展方法名称
$.fn.MyFrame = function (options) {
 //步骤3 合并用户自定义属性，默认属性(如果options为空，则使用defaults)
 var options = $.extend(defaults, options);
}
//步骤4 支持jQuery选择器
//步骤5 支持链式调用(将步骤4返回)
return this.each(function () {
 //步骤6 在插件里定义函数
 MyFun(this);
});
})(jQuery);

Due to scope Relationships, the private functions of step 6 are currently allowed for internal use by plugins.