Preferences class for storing/retrieving Titanium.App.Properties

checkFile.py

import os.path
def check(mypath):
         return os.path.isfile(mypath)

Preferences.js

/**
* Class name: Preferences.js
* Author: Codeboxed
* URL: http://www.codeboxed.com
* Date: March 7, 2011
* Platform: Titanium
*/

var Preferences = function() {
	// Private	
	var fileName 	= 'user.properties';
	var file	= null;
	var properties 	= null;
	var loaded	= false;
	
	/**
	* Private method used to get the filepath
	* @returns String
	*/
	var getPreferencesFile = function() {
		return Titanium.API.application.dataPath + Titanium.Filesystem.getSeparator() + fileName;
	};
	
	/**
	* Private method used to get the default properties
	* @returns Titanium.App.Properties
	*/
	var getDefaultPreferences = function() {
		return Titanium.App.createProperties({
			integer: 			0,
			string: 			"test",
			array: 				['a', 'b']
		});
	};

	/**
	* Private method used to init the properties
	*/
	var loadProperties = function() {		
		file = getPreferencesFile();

		if (check(file)) {
			properties = Titanium.App.loadProperties(file);
		}
		
		// The file does not exists. Create it
		if (properties === null) {
			properties = getDefaultPreferences();
		}
		
		loaded = true;
	};
	
	/**
	* Private method used to write the properties to the file
	*/
	var syncProperties = function() {
		if (loaded) {
			properties.saveTo(file);
		}
	};
	
	/**
	* Private method used to update a property
	* @param {string} key The property name
	* @param {string} value The property new value
	* @returns true if successfull, false otherwise
	*/
	var updateProperty = function(key, value) {
		if (loaded && properties.hasProperty(key)) {
			switch (typeof value) {
				case 'boolean':
					properties.setInt(key, value);
				break;
				case 'number':
					properties.setInt(key, value);
				break;
				case 'string':
					properties.setString(key, value);
				break;
				case 'object':
					properties.setList(key, value);
				break;
				default:
					return false;
			}
			
			return true;
		}
		
		return false;
	};
	
	/**
	* Private method used to get a property
	* @param {string} key The property name
	* @returns object|string|integer if successfull, null otherwise
	*/
	var getProperty = function(key) {
		if (loaded && properties.hasProperty(key)) {
			
			try {
				return properties.getString(key);	
			} catch(err) {
				try {
					return properties.getInt(key);
				} catch(err) {
					try {
						return properties.getList(key);
					} catch(err){
						console.log(err);
					}
				}
			}
			
		}
		
		return null;
	};

	// Public
	return {
		/**
		* Public method to act as a constructor
		*/
		init: function() {
			loadProperties();
		},
		
		/**
		* Public method used to update a property
		* @param {string} key The property name
		* @param {string} value The property new value
		*/
		change: function(key, value) {
			updateProperty(key, value);
		},
		
		/**
		* Public method used to get a property
		* @param {string} key The property name
		* @returns object|string|integer if successfull, null otherwise
		*/
		get: function(key) {
			return getProperty(key);
		},
		
		/**
		* Public method used to write the properties to the file
		*/
		save: function() {
			syncProperties();
		},
 		
		/**
		* Private method used to sync the properties
		*/
		sync: function() {
			loadProperties();
		}
 	};
};

// HOW TO USE
var preferences = new Preferences();
preferences.init();

preferences.get('integer');
preferences.change('string', 'string changed');
preferences.save();
preferences.get('string');