请问下下面这串代码说的大概是什么意思,
(function($, window, document, undefined) {
$.init();
var qsa = function() {
return [].slice.call(document.querySelectorAll.apply(document, arguments));
};
console.info(qsa("[_src]")+"\n"+99)
qsa("[_src]").forEach(function(item) {
item.addEventListener('tap', function() {
var url = this.getAttribute('_src');
if (url) {
plus.runtime.openURL(url);
};
}, false);
});
})(mui, window, document, undefined);
```