如何使用方法创建 jQuery 插件?

How to create a jQuery plugin with methods?(如何使用方法创建 jQuery 插件?)

问题描述

我正在尝试编写一个 jQuery 插件，该插件将为调用它的对象提供额外的功能/方法.我在网上阅读的所有教程(过去2小时一直在浏览)最多包括如何添加选项，而不是附加功能.

I'm trying to write a jQuery plugin that will provide additional functions/methods to the object that calls it. All the tutorials I read online (have been browsing for the past 2 hours) include, at the most, how to add options, but not additional functions.

这是我想做的事情:

//通过调用该div的插件将div格式化为消息容器

//format div to be a message container by calling the plugin for that div

$("#mydiv").messagePlugin();
$("#mydiv").messagePlugin().saySomething("hello");

或类似的东西.归结为:我调用插件，然后调用与该插件关联的函数.我似乎无法找到一种方法来做到这一点，而且我之前已经看到很多插件都这样做了.

or something along those lines. Here's what it boils down to: I call the plugin, then I call a function associated with that plugin. I can't seem to find a way to do this, and I've seen many plugins do it before.

这是我目前所拥有的插件:

Here's what I have so far for the plugin:

jQuery.fn.messagePlugin = function() {
  return this.each(function(){
    alert(this);
  });

  //i tried to do this, but it does not seem to work
  jQuery.fn.messagePlugin.saySomething = function(message){
    $(this).html(message);
  }
};

我怎样才能实现这样的目标?

How can I achieve something like that?

谢谢！

2013 年 11 月 18 日更新:我已将正确答案更改为 Hari 以下评论和点赞的答案.

Update Nov 18, 2013: I've changed the correct answer to that of Hari's following comments and upvotes.

推荐答案

根据 jQuery Plugin Authoring 页面 (http://docs.jquery.com/Plugins/Authoring)，最好不要混淆 jQuery 和 jQuery.fn 命名空间.他们建议采用这种方法:

According to the jQuery Plugin Authoring page (http://docs.jquery.com/Plugins/Authoring), it's best not to muddy up the jQuery and jQuery.fn namespaces. They suggest this method:

(function( $ ){

    var methods = {
        init : function(options) {

        },
        show : function( ) {    },// IS
        hide : function( ) {  },// GOOD
        update : function( content ) {  }// !!!
    };

    $.fn.tooltip = function(methodOrOptions) {
        if ( methods[methodOrOptions] ) {
            return methods[ methodOrOptions ].apply( this, Array.prototype.slice.call( arguments, 1 ));
        } else if ( typeof methodOrOptions === 'object' || ! methodOrOptions ) {
            // Default to "init"
            return methods.init.apply( this, arguments );
        } else {
            $.error( 'Method ' +  methodOrOptions + ' does not exist on jQuery.tooltip' );
        }    
    };


})( jQuery );

基本上，您将函数存储在数组中(范围为包装函数)，如果传递的参数是字符串，则检查条目，如果参数是对象(或空).

Basically you store your functions in an array (scoped to the wrapping function) and check for an entry if the parameter passed is a string, reverting to a default method ("init" here) if the parameter is an object (or null).

然后你可以像这样调用方法......

Then you can call the methods like so...

$('div').tooltip(); // calls the init method
$('div').tooltip({  // calls the init method
  foo : 'bar'
});
$('div').tooltip('hide'); // calls the hide method
$('div').tooltip('update', 'This is the new tooltip content!'); // calls the update method

Javascript 的参数"变量是一个包含所有传递参数的数组，因此它适用于任意长度的函数参数.

Javascripts "arguments" variable is an array of all the arguments passed so it works with arbitrary lengths of function parameters.

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