var helloWorld = “Hello World”;
var helloWorldCopy = helloWorld;

var helloWorld = {
  ‘hello': ‘world'
}
var helloWorldCopy = helloWorld;

var Person = Backbone.Model.extend({
  defaults: {
    'name': 'John Doe',
    'address': {
      'street': '1st Street'
      'city': 'Austin',
      'state': 'TX'
      'zipCode': 78701
    }
  }
});

var person = new Person({
  'name': 'Phillip W'
});

var Person = Backbone.Model.extend({
  validate: function(attributes) {
 
    if(isNaN(attributes.address.zipCode)) return "Address ZIP code must be a number!";
  },
 
  defaults: {
    'name': 'John Doe',
    'address': {
      'street': '1st Street'
      'city': 'Austin',
      'state': 'TX'
      'zipCode': 78701
    }
  }
});

var address = person.get('address');
address.zipCode = 'Hello World';
// Raises an error since the ZIP code is invalid
person.set('address', address, { validate: true });
console.log(person.get('address'));
/* Prints an object with these properties.
{
  'street': '1st Street'
  'city': 'Austin',
  'state': 'TX'
  'zipCode': 'Hello World'
}
*/

var address = $.extend(true, {}, person.address);

var Hotel = Backbone.Model.extend({
  defaults: {
    "availableRooms": ["a"],
    "rooms": {
      "a": {
        "size": 1200,
        "bed": "queen"
      },
      "b": {
        "size": 900,
        "bed": "twin"
      },
      "c": {
        "size": 1100,
        "bed": "twin"
      }
    },
 
    getRooms: function() {
      $.extend(true, {}, this.get("rooms"));
    },
 
    getRoomsByBed: function(bed) {
      return _.where(this.getRooms(), { "bed": bed });
    }
  }
});

var Hotel = Backbone.Model.extend({
  defaults: {
    "availableRooms": ["a"],
    "rooms": [
      {
        "name": "a",
        "size": 1200,
        "bed": "queen"
      },
      {
        "name": "b",
        "size": 900,
        "bed": "twin"
      },
      {
        "name": "c",
        "size": 1100,
        "bed": "twin"
      }
    ],
 
    getRooms: function() {
      var rooms = $.extend(true, {}, this.get("rooms")),
       newRooms = {};
 
      // transform rooms from an array back into an object
      _.each(rooms, function(room) {
        newRooms[room.name] = {
          "size": room.size,
          "bed": room.bed
        }
      });
    },
 
    getRoomsByBed: function(bed) {
      return _.where(this.getRooms(), { "bed": bed });
    }
  }
});

<ul>
  <li><a href="#" data-id="1">One</a></li>
  <li><a href="#" data-id="2">Two</a></li>
  . . .
  <li><a href="#" data-id="n">n</a></li>
</ul>

var Model = Backbone.Model.extend({
  defaults: {
    items: [
      {
        "name": "One",
        "id": 1     
      },
      {
        "name": "Two",
        "id": 2     
      },
      {
        "name": "Three",
        "id": 3     
      }
    ]
  }
});
 
var View = Backbone.View.extend({
  template: _.template($('#list-template').html()),
 
  events: {
    "#items li a": "setSelectedItem"
  },
 
  render: function() {
    $(this.el).html(this.template(this.model.toJSON()));
  },
 
  setSelectedItem: function(event) {
    var selectedItem = $(event.currentTarget);
    // Set all of the items to not have the selected class
    $('#items li a').removeClass('selected');
    selectedItem.addClass('selected');
    return false;
  }
});
 
<script id="list-template" type="template">
<ul id="items">
    <% for(i = items.length - 1; i >= 0; i--) { %>
  <li>
        <a href="#" data-id="<%= item[i].id %>"><%= item[i].name %></a></li>
<% } %></ul>
</script>

var View = Backbone.View.extend({
  initialize: function(options) {
    // Re-render when the model changes
    this.model.on('change:items', this.render, this);
  },
 
  template: _.template($('#list-template').html()),
 
  events: {
    "#items li a": "setSelectedItem"
  },
 
  render: function() {
    $(this.el).html(this.template(this.model.toJSON()));
  },
 
  setSelectedItem: function(event) {
    var selectedItem = $(event.currentTarget);
    // Set all of the items to not have the selected class
    $('#items li a').removeClass('selected');
    selectedItem.addClass('selected');
    // Store a reference to what item was selected
    this.selectedItemId = selectedItem.data('id'));
    return false;
  }
});

var View = Backbone.View.extend({
  initialize: function(options) {
    this.model.on('change', this.render, this);
  },
 
  template: _.template($(‘#template').html()),
 
  render: function() {
    this.$el.html(template(this.model.toJSON());
    $(‘#a', this.$el).html(this.model.get(‘a'));
    $(‘#b', this.$el).html(this.model.get(‘b'));
  }
});

var View = Backbone.View.extend({
  initialize: function(options) {
    this.model.on('change:a', this.renderA, this);
    this.model.on('change:b', this.renderB, this);
  },
 
  renderA: function() {
    $(‘#a', this.$el).html(this.model.get(‘a'));
    return this;
  },
 
  renderB: function() {
    $(‘#b', this.$el).html(this.model.get(‘b'));
    return this;
  },
 
  render: function() {
    this
      .renderA()
      .renderB();
  }
});

'search/:foo'
'search/:bar'
'search/:foo/:bar'

routes: { 'search/:foo': 'searchFoo', 'search/:bar': 'searchBar', 'search/:foo/:bar': 'search' }, search: function(foo, bar) { }, // I know this function will actually still map correctly, but for explanatory purposes, it's left in. searchFoo: function(foo) { this.search(foo, undefined); }, searchBar: function(bar) { this.search(undefined, bar); },

routes: {
  'search/:foo': 'searchFoo',
  'search/:bar': 'searchBar',
  'search/:foo/:bar': 'search'
},
 
search: function(foo, bar) {  
},
 
// I know this function will actually still map correctly, but for explanatory purposes, it's left in.
searchFoo: function(foo) {
  this.search(foo, undefined);
},
 
searchBar: function(bar) {
  this.search(undefined, bar);
},

var Model = Backbone.Model.extend({
  defaults: {
    x: 1,
    y: 1,
    z: 1
  }
});
var model = new Model();
/* model.attributes yields
{
  x: 1,
  y: 1,
  z: 1
} */
model.fetch();
/* let's assume that the endpoint returns this
{
  y: 2,
  z: 2,
} */
/* model.attributes now yields
{
  x: 1,
  y: 2,
  z: 2
} */

parse: function(response) {
 
  _.each(response.cars, function(car, i) {
    // map the returned ID of carID to the correct attribute ID
    response.cars[i].id = response.cars[i].carID;
  });
 
  return response;
},

// a single attribute
var model = new Model({
  hello: <%= @world %>
});
// or to have json
var model = new Model(<%= @hello_world.to_json %>);

// Inside your model
validate: function(attrs) {
  var errors = [];
 
  if(attrs.a < 0) {
    errors.push({
      'message': 'Form field a is messed up!',
      'class': 'a'
    });
  }
  if(attrs.b < 0) {
    errors.push({
      'message': 'Form field b is messed up!',
      'class': 'b'
    });
  }
 
  if(errors.length) {
    return errors;
  }
}
// Inside your view
this.model.on('invalid', function(model, errors) {
  _.each(errors, function(error, i) {
    $(‘.' + error.class).addClass('error');
    alert(error.message);
  });
});

// Inside your model
validate: function(attrs) {
 
  if(attrs.a < 0) {
      this.trigger(‘invalid:a', 'Form field a is messed up!', this);
  }
  if(attrs.b < 0) {
      this.trigger(‘invalid:b', 'Form field b is messed up!', this);
  }
}
// Inside your view
this.model.on('invalid:a', function(error) {
    $(‘a').addClass('error');
    alert(error);
});
this.model.on('invalid:b', function(error) {
    $(‘b').addClass('error');
    alert(error);
});

var AlertView = Backbone.View.extend({
  set: function(typeOfError, message) {
    var alert = $(‘.in-page-alert').length ? $(‘.in-page-alert'): $(‘.body-alert');
    alert
      .removeClass(‘error success warning')
      .addClass(typeOfError)
      .html(message)
      .fadeIn()
      .delay(5000)
      .fadeOut();
  }
});

var alert = new AlertView();
 
this.model.on('error', function(model, error) {
  alert.set('TYPE-OF-ERROR', error);
});

Backbone.Router = Backbone.Router.extend({
 
  initialize: function(options){
    var that = this;
 
    this.on('route', function(router, route, params) {
 
      if(that.titles) {
        if(that.titles[router]) document.title = that.titles[router];
        else if(that.titles.default) document.title = that.titles.default;
        else throw 'Backbone.js Router Title Helper: No title found for route:' + router + ' and no default route specified.';
      }
    });
  }
});

 
// Inside a router
initialize: function() {
 
  this.cached = {
    view: undefined,
    model: undefined
  }
},
 
index: function(parameter) {
  this.cached.model = this.cached.model || new Model({
    parameter: parameter
  });
  this.cached.view = this.cached.view || new View({
    model: this.cached.model
  });
}

// Inside a router
initialize: function() {
 
  this.cached = {
    view: undefined,
    model: undefined
  }
},
 
index: function(parameter) {
  this.cached.model = this.cached.model || new Model({
    parameter: parameter
  });
  this.cached.view = this.cached.view || new View({
    model: this.cached.model
  });
  this.cached.model.fetch();
}

// Inside a router
initialize: function() {
 
  this.cached = {
    view: undefined,
    model: undefined
  }
},
 
index: function(parameter) {
  this.cached.model = this.cached.model || new Model({
    parameter:parameter
  });
  this.cached.model.set('parameter', parameter);
  this.cached.view = this.cached.view || new View({
    model: this.cached.model
  });
}
 
// Inside of the model
initialize: function() {
  this.on("change:parameter", this.fetchData, this);
}

var Thing = Backbone.View.extend(/** @lends Thing.prototype */{
  /** @class Thing
   * @author Phillip Whisenhunt
   * @augments Backbone.View
   * @contructs Thing object */
  initialize() {},
 
  /** Gets data by ID from the thing. If the thing doesn't have data based on the ID, an empty string is returned.
   * @param {String} id The id of get data for.
   * @return {String} The data. */
  getDataById: function(id) {}
});