jqueryui如何知道如何绑定作为init选项提供的事件回调?

我对jQueryUI代码不太熟悉,但下面是一个如何调用作为参数传递的回调的示例。

试一试: http://jsfiddle.net/pshLK/

当示例加载时,您将收到2个警报。这是为两个匹配的 <div>

(function($) {
       // create myPlugin
    $.fn.myPlugin = function(options) {
           // iterate through all elements the selector matched
        return this.each(function() {
                // Change the color to blue
            $(this).css('color','blue');
                // Call the callback using the .call() method
                //    so that we can pass the value of "this"
                //    as the element in the iteration
            options.callback.call(this);
        });
    };
})(jQuery);

   // Find all <div> elements on the page, and call myPlugin which
   //   receives an object as an argument that has a "callback" property
   //   whose value is the function that will be called in the plugin.
$('div').myPlugin({
         // This function will run for each <div> displaying the ID of the <div>
    callback:function() { alert('the id is ' + this.id); }
});

JavaScript中的函数可以作为值传递给其他函数并执行。例如。:

function execute(fn)
{
    fn(); // execute function passed as a parameter
}

var alertHelloWorld = function ()
{
    alert("Hello World");
};

execute(alertHelloWorld); // this will alert "Hello World"

因此jQuery Autocomplete插件所做的就是缓存传递给它的初始值设定项的任何函数,然后在需要时执行它们。即:当数据需要处理或数据已经处理时。

下面是一个类似于Autocomplete插件的示例:

// execute three functions contained in an object literal
function execute(o)
{
    o.One();
    o.Two();
    o.Three();
};

// call "execute" passing in object literal containing three anonymous functions
// this will alert "One", then "Two", then "Three"
execute(
{
    One: function () { alert("One"); },
    Two: function () { alert("Two"); },
    Three: function () { alert("Three"); }
});

function execute(fn)
{
    // execute function passed as a parameter with a parameter
    fn("Hello World");
};

execute(function (s)
{
    // parameter "s" supplied by "execute" will contain "Hello World"
    alert(s);
});