function isItOkay() {
var myMessageData = event.url;
var theAnswer = safari.self.tab.canLoad(event, myMessageData);
if (theAnswer == "block") {
event.preventDefault();
}
}
document.addEventListener("beforeload", isItOkay, true);
function blockOrAllow(event) {
if (event.name === "canLoad") {
var itsAnAd = event.message.match(/ads.example.com/i);
if (itsAnAd) {
event.message = "block";
}
else {
event.message = "allow";
}
}
}
safari.application.addEventListener("message", blockOrAllow, true);