吐槽新浪某个页面的JS

//byid

SAB.register('dom.byId',function($){

return function(id){

if (typeof id === 'string') {

return document.getElementById(id);

}

else {

return id;

}

};

});

//byclass

SAB.register('dom.byClass',function($){

return function(clz,el,tg){

el = el || document;

el = typeof el=='string'?$.dom.byId(el):el;

tg = tg || '*';

var rs = [];

clz = " " + clz +" ";

var cldr = el.getElementsByTagName(tg), len = cldr.length;

for (var i = 0; i < len; ++ i){

var o = cldr[i];

if (o.nodeType == 1){

var ecl = " " + o.className + " ";

if (ecl.indexOf(clz) != -1){

rs[rs.length] = o;

}

}

}

return rs;

};

});

 

 至少应该先判断下有没有getElementsByClassName这个函数吧，这么做真是太奢侈了。