A binary file download script that also works on android 4.1 - 4.3 devices (without XMLHttpRequest blob support)

imagedownload.js

function getImageFile(path, callback) {

	path = path.replace('https://', 'http://'); // android is very picky with https certificates and does not give an error
	console.info("Requesting Image File for Splashscreen: " + path);

	if(path == null) {
		// handle empty urls by passing on the null value
		callback(null);
		return deferred.promise;
	}

	try {
		var xhr = new XMLHttpRequest();
		try {
			xhr.responseType = 'blob';
		} catch (e) {
			console.info('Feature detection failed');
		}

		console.info("xhr responsetype" + xhr.responseType);

		if (xhr.responseType == 'blob') {
			xhr.addEventListener("load", function (e) {
				var blob = new Blob([xhr.response], {type: 'image/png'});
				callback(blob);
				console.log('xhr returned');
			});
		} else {

			// using fallback mode described in various internet forums
			console.info('before override mime type');
			// to avoid getting the response mangled by the xhr request
			xhr.overrideMimeType('text\/plain; charset=x-user-defined');
			console.info('after override mime type');

			xhr.addEventListener("load", function (e) {

				console.info('before checking length');
				console.info('before converting blob' + xhr.response.length);

				// this is necessary else some overlong bytes are getting mangled
				var l, d, array;
				d = xhr.response;
				l = d.length;
				array = new Uint8Array(l);
				console.info("Got Uint8Array");
				for (var i = 0; i < l; i++) {
					array[i] = d.charCodeAt(i) & 0xff;
				}

				// now we finally can create a blob
				var blob = new Blob([array.buffer], {type: 'image/png', 'endings': "transparent"});
				console.info('got blob');
				callback(blob);
			});
		}

		xhr.addEventListener("error", function (e) {
			console.info('xhr error' + JSON.stringify(e));
			callback(e)
		});

		xhr.open('GET', path, true);
		xhr.send(null);
	} catch (e) {
		console.log('Exception' + e);
	}
}