jquery------提供灵活的方法参数

<h1 >再次重逢的世界</h1>

$(document).ready(function(){
(function($){
$.fn.shadow=function(opt){
/*var defaults={
copies:15,
opacity:0.1,
colors:"blue",
copyOffset:function(index){
return {x:index,y:index};
},
};*/

var option=$.extend({},$.fn.shadow.defaults,opt);

return this.each(function(){
var $original=$(this);
for(var i=0;i<option.copies;i++){
var offset=option.copyOffset(i);
$original
.clone()  //复制元素
.css({
position:"absolute",
left:$original.offset().left+offset.x,
top:$original.offset().top+i+offset.y,
color:option.colors,
margin:0,
padding:0,
zIndex:-1,
opacity:option.opacity})
.appendTo("body");
}
});
};

$.fn.shadow.defaults={
copies:15,
opacity:0.1,
colors:"red",
copyOffset:function(index){
return {x:index,y:index};
},
};
})(jQuery);

$.fn.shadow.defaults.copies=10;
$("h1").shadow({
//copies:15,
opacity:0.1,
copyOffset:function(index){
return {x:-index,y:-2*index};
},
colors:"blue",
});

});