Using ti.identity for keychain functionality in Titanium applications

keichainService.js

const TiIdentity = require('ti.identity');

//Identifier of the application. The same as development team on provisioning profile
const appIdentifierPrefix = 'YOUR_IDENTIFIER';

//Create the Keychain Items
const keychainUn = TiIdentity.createKeychainItem({
  identifier: Alloy.CFG.kc_user_identifier,
  accessGroup: appIdentifierPrefix + '.' + Ti.App.id
});
const keychainPw = TiIdentity.createKeychainItem({
  identifier: Alloy.CFG.kc_pw_identifier,
  accessGroup: appIdentifierPrefix + '.' + Ti.App.id
});

//Listeners for verifiyng that save/read works (remove from production apps!)

// Triggered when the keychain item was successfully saved
keychainUn.addEventListener('save', function(e) {
    // Notify the user that the operation succeeded or failed
    console.log('USERNAME SAVED');
});
// Triggered when the keychain item was successfully saved
keychainUn.addEventListener('read', function(e) {
    // Notify the user that the operation succeeded or failed
    console.log('USERNAME READ:', e);
});


/**
 *    Check if the provided Keychain Item exits, and returns it's value
 *    @param  {Object} keychainItem   the keychain item to get value from
 *    @return {String}                value of the keychain item
 */
const getKeychainValue = (keychainItem) => {
  return new Promise((resolve, reject) => {
    //Check if keychain item with identifier exists
    keychainItem.fetchExistence((e) => {
      if (e.exists) {
        //Read value of the keychain item
        keychainItem.addEventListener('read', (e) => {
          if (!e.success) {
            Ti.API.error('Error: ' + e.error);
            reject(null);
          }
          //Return the value
          resolve(e.value);
        });
        keychainItem.read();
      } else {
        console.error('Could not find KeychainItem. Incorrect appIdentifierPrefix?');
        reject(null);
      }
    });
  });
};

/**
 *    Saves a value to a Keychain Item. If it already exist, it gets updated
 *    @param  {Object} keychainItem   keychain item to set value to
 *    @param  {String} val            value to save
 */
const saveKeychainValue = (keychainItem, val) => {
  keychainItem.fetchExistence((e) => {
    if (e.exists) {
      keychainItem.update(val);
    } else {
      keychainItem.save(val);
    }
  });
};

//Get a 'user credentials' object
exports.getCredentials = async () => {
  return {
    un: await getKeychainValue(keychainUn),
    pw: await getKeychainValue(keychainPw)
  };
};

//Save functions
exports.setUsername = (email) => saveKeychainValue(keychainUn, email);
exports.setPassword = (pw) => saveKeychainValue(keychainPw, pw);

//Reset functions
exports.resetUsername = () => keychainUn.reset();
exports.resetPassword = () => keychainPw.reset();

keychain.js

const keychain = require('/keychainService');

//Save username/password to keychain
keychain.setUsername('SOME_USERNAME');
keychain.setPassword('SOME_PASSWORD');

//Get credentials object ({username, password})
keychain.getCredentials();

//Reset keychain storage
keychain.resetUsername();
keychain.resetPassword();