jquery插件编写思路

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function(e) {

    e.fn.floatNav = function(t) {

        var i = e.extend({

            start: null,

            end: null,

            fixedClass: "nav-fixed",

            anchor: null,

            targetEle: null,

            range: 0,

            onStart: function() {},

            onEnd: function() {}

        },

        t),

        s = e(this),

        a = s.height(),

        o = s.width(),

        n = e('<div class="float-nav-wrap"/>');   //以逗号分隔各个值，一次定义多个变量//return 返回用逗号隔开的各个值，这里用到了逗号表单式，把this单签这个对象放到最后，确保逗号表达式返回的是当前的这个jquery对象，这样写，确保了每个逗号表达式中的语句都被执行

        return s.css({            

            height: a,

            width: o

        }),

        s.parent().hasClass("float-nav-wrap") || s.wrap(n.css("height", a)),   //先判断下父级是否有float-nav-wrap这个对象，如果有的话，则执行后面的s.wrap(n.css("height", a))语句

        e(window).bind("scroll",

        function() {

            var t = e(document).scrollTop(),

            a = s.find("a").eq(0).attr("href"),

            o = i.start || s.parent(".float-nav-wrap").offset().top,

            n = i.targetEle ? e(i.targetEle).offset().top: 1e4;

            t > o && (i.end || n) - i.range > t ? (s.addClass(i.fixedClass), i.anchor && a !== i.anchor && s.find("a").attr("href", i.anchor), i.onStart && i.onStart()) : (s.removeClass(i.fixedClass), i.anchor && s.find("a").attr("href", "javascript:;"), i.onEnd && i.onEnd())

        }),

        this

    }

} (jQuery),