iOS/Android: permanently caching imageView

app.js

App.UI.Image = function(_params) {
	_params.preventDefaultImage = true;
	
	var folder = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, "cache");
	
	if(!folder.exists()){
		folder.createDirectory(); 
	}
	
	var filename = Ti.Utils.base64encode(_params.image.toString());
	// Android can't copy build with files over 100 in lenght http://jira.appcelerator.org/browse/TIMOB-6495'
	if(filename.length > 99){
		filename = new String(filename).slice(filename.length - 99);
	}
	var file = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, "cache" + Ti.Filesystem.separator + filename);
	
	if(file.exists()) {
		_params.image = file.nativePath;
	} else {
		App.UI.ImageCache(_params.image);
	}
	
	return Ti.UI.createImageView(_params);
};

App.UI.ImageCache = function(_location) {
	var httpc = Ti.Network.createHTTPClient();
	
	httpc.onload = function() {
		if(httpc.status == 200) {
			var filename = Ti.Utils.base64encode(_location);
			if(filename.length > 99){
				filename = new String(filename).slice(filename.length - 99);
			}
			var file = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, "cache" + Ti.Filesystem.separator + filename);
			
			file.write(httpc.responseData);
		}
	};
	
	httpc.open("GET", _location);
	httpc.send();
};