backbone.md

title	updated	category
Backbone.js	2018-12-06	JavaScript libraries

Binding events

.on('event', callback)
.on('event', callback, context)

.on({
  'event1': callback,
  'event2': callback
})

.on('all', callback)

.once('event', callback)   // Only happens once

Unbinding events

object.off('change', onChange)    // just the `onChange` callback
object.off('change')              // all 'change' callbacks
object.off(null, onChange)        // `onChange` callback for all events
object.off(null, null, context)   // all callbacks for `context` all events
object.off()                      // all

Events

object.trigger('event')

view.listenTo(object, event, callback)
view.stopListening()

List of events

• Collection:

  • add (model, collection, options)
  • remove (model, collection, options)
  • reset (collection, options)
  • sort (collection, options)

• Model:

  • change (model, options)
  • change:[attr] (model, value, options)
  • destroy (model, collection, options)
  • error (model, xhr, options)

• Model and collection:

  • request (model, xhr, options)
  • sync (model, resp, options)

• Router:

  • route:[name] (params)
  • route (router, route, params)

Views

Defining

// All attributes are optional
var View = Backbone.View.extend({
  model: doc,

  tagName: 'div',
  className: 'document-item',
  id: "document-" + doc.id,
  attributes: { href: '#' },

  el: 'body',

  events: {
    'click button.save': 'save',
    'click .cancel': function() { ··· },
    'click': 'onclick'
  },

  constructor: function() { ··· },
  render: function() { ··· }
})

Instantiating

view = new View()
view = new View({ el: ··· })

Methods

view.$el.show()
view.$('input')

view.remove()

view.delegateEvents()
view.undelegateEvents()

Models

Defining

// All attributes are optional
var Model = Backbone.Model.extend({
  defaults: {
    'author': 'unknown'
  },
  idAttribute: '_id',
  parse: function() { ··· }
})

Instantiating

var obj = new Model({ title: 'Lolita', author: 'Nabokov' })

var obj = new Model({ collection: ··· })

Methods

obj.id
obj.cid   // → 'c38' (client-side ID)

obj.clone()

obj.hasChanged('title')
obj.changedAttributes()  // false, or hash
obj.previousAttributes() // false, or hash
obj.previous('title')

obj.isNew()

obj.set({ title: 'A Study in Pink' })
obj.set({ title: 'A Study in Pink' }, { validate: true, silent: true })
obj.unset('title')

obj.get('title')
obj.has('title')
obj.escape('title')     /* Like .get() but HTML-escaped */

obj.clear()
obj.clear({ silent: true })

obj.save()
obj.save({ attributes })
obj.save(null, {
  silent: true, patch: true, wait: true,
  success: callback, error: callback
})

obj.destroy()
obj.destroy({
  wait: true,
  success: callback, error: callback
})

obj.toJSON()

obj.fetch()
obj.fetch({ success: callback, error: callback })

Validation

var Model = Backbone.Model.extend({
  validate: function(attrs, options) {
    if (attrs.end < attrs.start) {
      return "Can't end before it starts"
    }
  }
})

{: data-line="2"}

obj.validationError  //=> "Can't end before it starts"
obj.isValid()
obj.on('invalid', function (model, error) { ··· })

// Triggered on:
obj.save()
obj.set({ ··· }, { validate: true })

Custom URLs

var Model = Backbone.Model.extend({
  // Single URL (string or function)
  url: '/account',
  url: function() { return '/account' },

  // Both of these two work the same way
  url: function() { return '/books/' + this.id }),
  urlRoot: '/books'
})

var obj = new Model({ url: ··· })
var obj = new Model({ urlRoot: ··· })

References

{: .-one-column}

• Backbone website (backbonejs.org)
• Backbone patterns (ricostacruz.com)