jquery.scrollLoading.js

/*!
* jquery.scrollLoading.js
* by zhangxinxu  http://www.zhangxinxu.com * 2010-11-19 v1.0
* 2012-01-13 v1.1 偏移值计算修改 position → offset
* 2012-09-25 v1.2 增加滚动容器参数, 回调参数
*/
(function($) {
$.fn.scrollLoading = function(options) {
var defaults = {
attr: "data-url",
container: $(window),
callback: $.noop
};
var params = $.extend({}, defaults, options || {});
params.cache = [];
$(this).each(function() {
var node = this.nodeName.toLowerCase(), url = $(this).attr(params["attr"]);
//重组
var data = {
obj: $(this),
tag: node,
url: url
};
params.cache.push(data);
});

var callback = function(call) {
if ($.isFunction(params.callback)) {
params.callback.call(call.get(0));
}
};
//动态显示数据
var loading = function() {

var contHeight = params.container.height();
if ($(window).get(0) === window) {
contop = $(window).scrollTop();
} else {
contop = params.container.offset().top;
}

$.each(params.cache, function(i, data) {
var o = data.obj, tag = data.tag, url = data.url, post, posb;

if (o) {
post = o.offset().top - contop, post + o.height();

if ((post >= 0 && post < contHeight) || (posb > 0 && posb <= contHeight)) {
if (url) {
//在浏览器窗口内
if (tag === "img") {
//图片，改变src
callback(o.attr("src", url));
} else {
o.load(url, {}, function() {
callback(o);
});
}
} else {
// 无地址，直接触发回调
callback(o);
}
data.obj = null;
}
}
});
};

//事件触发
//加载完毕即执行
loading();
//滚动执行
params.container.bind("scroll", loading);
};
})(jQuery);