Skip to content

Instantly share code, notes, and snippets.

@marlocorridor
Last active May 17, 2016 08:04
Show Gist options
  • Save marlocorridor/55151669b3395d6ce10c5e22171eb22d to your computer and use it in GitHub Desktop.
Save marlocorridor/55151669b3395d6ce10c5e22171eb22d to your computer and use it in GitHub Desktop.
Loads the assets to be cached by the browser.
// depends on jQuery
var PreloaderClass = function (urls) {
// holds the URLs passed
this.urls = urls;
// base loading
this.loadUrl = function ( url ) {
var supported, deferredLoading, xhr;
deferredLoading = jQuery.Deferred();
supported = typeof new XMLHttpRequest().responseType === 'string';
if (supported) {
xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'arraybuffer';
xhr.onreadystatechange = function () {
if (xhr.readyState === 4) {
if (xhr.status === 200) {
deferredLoading.resolve( xhr );
} else {
deferredLoading.reject( xhr );
}
}
};
xhr.onprogress = function (evt) {
if(evt.lengthComputable) {
deferredLoading.notify(evt.loaded, evt.total);
}
};
xhr.send(null);
}
return deferredLoading;
};
// action method
this.preload = function () {
var self = this;
var deferredLoads = [];
this.urls.forEach(function (url) {
var getDeferredLoad = self.loadUrl( url );
deferredLoads.push(
getDeferredLoad
);
})
return $.when.apply($, deferredLoads);
}
};
//preloader usage
(function () {
var url_set = [
//enter URLs here
];
// creates instance
window.Preloader = new PreloaderClass( url_set );
// execute preloading
Preloader.preload();
})();
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment