Peter Lubbers - Pro HTML 5 Programming

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CHAPTER 10 ■ CREATING HTML5 OFFLINE WEB APPLICATIONS
}
} catch (e) {
applicationCache.onerror();
}
onload = function(e) {
// Check for required browser features
if (!window.applicationCache) {
log("HTML5 Offline Applications are not supported in your browser.");
return;
}
}
if (!navigator.geolocation) {
log("HTML5 Geolocation is not supported in your browser.");
return;
}
if (!window.localStorage) {
log("HTML5 Local Storage not supported in your browser.");
return;
}
log("Initial cache status: " + showCacheStatus(window.applicationCache.status));
document.getElementById("installButton").onclick = checkFor;
log = function() {
var p = document.createElement("p");
var message = Array.prototype.join.call(arguments, " ");
p.innerHTML = message;
document.getElementById("info").appendChild(p);
}
Check for ApplicationCache Support
In addition to the offline application cache, this example uses geolocation and local storage. We ensure
that the browser supports all of these features when the page loads.
onload = function(e) {
// Check for required browser features
if (!window.applicationCache) {
log("HTML5 Offline Applications are not supported in your browser.");
return;
}
if (!navigator.geolocation) {
log("HTML5 Geolocation is not supported in your browser.");
return;
}