Register listeners

var Baobab = require('baobab');

var tree = new Baobab({
  todos: []
});

// Register to updates
tree.select('todos').on('update', function () {
  // I triggered 
});

tree.select('todos').push('foo');

// Register to state being removed from storage
tree.select('todos').on('irrelevant', function () {
  // I triggered
});

tree.edit({});

// Register to state being added to storage
tree.select('todos', 0).on('relevant', function () {
  // I triggered
});

tree.select('todos').push('foo');

Combined listeners

At times, you might want to listen to updates concerning a logical combination of cursors. For instance, you might want to know when two cursors both updated or when either one or the other did.

var Baobab = require('baobab');

var tree = new Baobab({
  todos: [],
  emails: [],
  notifications: []
});

var todos = tree.select('todos');
var notifications = tree.select('notifications');
var emails = tree.select('emails');

// Simple "or" combination
var todosOrNotifications = todos.or(notifications);

// Simple "and" combination
var todosAndNotifications = todos.and(notifications);

// Complex combination
var todosOrEmailsAndNotifications = todos.or(emails).and(notifications);

// Listening to events
todosOrEmailsAndNotifications.on('update', handler);

// Releasing a combination to avoid leaks
todosOrEmailsAndNotifications.release();