Hoodie Plugin that maintains a local list of user accounts that have been used in a browser. See discussion at https://github.com/hoodiehq/discussion/issues/42

hoodie.plugins.js

'use strict';

var hoodie = require('backbone').hoodie;
hoodie.extend(function(hoodie,lib, utils) {
  var PROFILES_STORE_KEY = '_hoodie_profiles';
  var store = utils.localStorageWrapper;
  var api = getAllProfiles;
  var profiles = store.getObject(PROFILES_STORE_KEY) || [];

  //
  // Initialization
  //
  hoodie.account.on('signin signup', handleAccountSignInOrSignUp);

  //
  // PUBLIC API
  //

  //
  api.find = function find(username) {
    for (var i = 0; i < profiles.length; i++) {
      if (profiles[i].username === username) return profiles[i];
    }
  };

  //
  api.add = function add(username, properties) {
    var existingProfile = api.find(username);
    if (!properties) properties = {};

    if (existingProfile) return api.update(username, properties);

    properties.username = username;
    profiles.push(properties);
    persistChanges();
    return true;
  };

  //
  api.update = function update(username, changedProperties) {
    var existingProfile = api.find(username);
    if (! existingProfile) return false;

    for (var property in changedProperties) {
      if (changedProperties.hasOwnProperty(property)) {
        existingProfile[property] = changedProperties[property];
      }
    }

    persistChanges();
    return true;
  };

  //
  api.remove = function remove(username) {
    var existingProfile = api.find(username);

    if (! existingProfile) return false;

    profiles.splice(existingProfile, 1);
    persistChanges();
    return true;
  };

  //
  api.clear = function clear() {
    profiles = [];
    persistChanges();
    return true;
  };

  //
  api.lastActive = function lastActive() {
    if (! profiles.length) return;

    return profiles.sort( function(profile1, profile2) {
      return profile1.lastActiveAt > profile2.lastActiveAt ? -1 : 1;
    })[0];
  };

  //
  // INTERNAL HELPERS
  //

  function getAllProfiles() {
    return profiles;
  }

  function persistChanges () {
    if (profiles.length) {
      store.setObject(PROFILES_STORE_KEY, profiles);
      return;
    }

    store.removeItem(PROFILES_STORE_KEY);
  }

  function handleAccountSignInOrSignUp (username) {
    api.add(username, {lastActiveAt: new Date().toJSON()});
    persistChanges();
  }

  hoodie.profiles = api;
});