This file is a cache module for Appcelerator Platform, now it works just with images but can be extended to support other stuff. Currently supports n number of retries and gets the image path on a callback, so you don't need to fake a dummy imageView if you want to precache some image.

cache.js

exports.image = function(url, callback, directory) {
	
	if (directory === undefined) {
		var directory = 'cachedImages';
	}

	var filename = Ti.Utils.md5HexDigest(url);
	var file = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, directory, filename);
	
	if (file.exists()) {
		callback(file.nativePath);
		file = null;
	} else {
		
		checkIfPathExistOrCreateIt(directory);
		var retries = 5;
		getRemoteFile(url, retries, function (responseData){
			file.write(responseData);
			callback(file.nativePath);
			file = null;
		});
		
	}

};

function checkIfPathExistOrCreateIt(directory) {

	var fileSystem = Ti.Filesystem.applicationDataDirectory;
	var folder = Ti.Filesystem.getFile(fileSystem, directory);
	if (!folder.exists()) {
		folder.createDirectory();
	}

};

function getRemoteFile(url, retries, success) {

	var http = Ti.Network.createHTTPClient();
	http.onload = function() {

		if (http.status == 200) {
			success(http.responseData);
		} else {
			if (retries > 0) {
				getRemoteFile(url, success, retries - 1);
			} else {
				console.log('making too much retries, stopping for url ' + url);
			}
		}

	};

	http.open('GET', url);
	http.send();

};


/*
Usage:

var cachedImage = require("cache").image;
var url = "http://placekitten.com/200/300";

cachedImage(url, function (imgPath){
  $.someImageView.image = imgPath;
});

If you want to pre-cache something you can use it like this:
cachedImage(url, function (imgPath){});

If you want to use another folder as the cache folder, to avoid collision, you can specify it. By default it will use "cachedImages" folder.
cachedImage(url, function (imgPath){}, 'SomeOtherCacheFolder');

*/