Understanding backbonejs
1 like2,628 views
This document provides an overview of using the Backbone.js framework for client-side MVC applications. It discusses why Backbone is useful for structuring JavaScript applications, its core architecture including models, collections, views and routers. It also provides examples of how to convert jQuery code to use a Backbone-based approach and lists some real-world applications that use Backbone.
Understanding backbonejs
- 1. Client-side MVC with Backbone.js Jquery to Backbone.js
- 2. Agenda • Why Backbone.js • Architecture • Jquery to Backbone.js • Real World Examples • Resources • Extras • Questions
- 3. Why backbonejs • From server-side to client-side • From server-side to client-side We need efficient tools • Jquery is cool but…
- 4. Why backbone.js • We have to store object informations into the DOM var list = ""; $.each(data, function (index, value) { list += "<li id="item-" + value.Id + "">" + value.Name + "</li>"; }); $("ul").append(list);
- 5. Callback hell jQuery callback hell $.getJSON("/Items", function (data) { var list = ""; $.each(data, function (index, value) { list += "<li id="item-" + value.Id + "">" + value.Name + "</li>"; } ); $("ul").append(list); $("li").click(function () { var $this = $(this); var id = $this.attr("id").replace("item-", ""); $.post("/Items", { id: id }, function () { $this.fadeOut(function () { $this.remove(); }); }); });
- 6. Why Backbone.js “Its all too easy to create JavaScript applications that end up as tangled piles of Jquery selectors and callbacks.” • So, what do we need? • Abstraction. • Decoupling UI from Data. • No more callbacks.
- 7. Why Backbone.js • A RESTful service based data layer. • Events (to keep UI and data up-to-date). • A template engine. • A solid routing system. • All the above things wrapped into a lightweight JavaScript framework.
- 8. Architecture • Oct 13th, 2010 Jeremy Ashkenas • http://documentcloud.github.com/backbone • https://github.com/documentcloud/backbone • @documentcloud • #documentcloud on IRC • https://groups.google.com/forum/#!forum/ba ckbonejs
- 9. Architecture • Backbone.js gives structure to web applications by providing models with key- value binding and custom events, • collections with a rich API of enumerable functions, • views with declarative event handling, • and connects it all to your existing API over a RESTful JSON interface.
- 10. Dependencies • jQuery or Zepto • Underscore.js • Json2.js
- 11. MVC • Model / Collection • Template (View) • View (Controller) • Router
- 12. Model • Representing data (auto-generated). • Handling persistence. • Throws events. • Reusable.
- 13. Model • Fetch HTTP GET /url • Save (new) HTTP POST /url • Save HTTP PUT /url/id • Destroy HTTP DELETE /url/id
- 14. Model var Item = Backbone.Model.extend({ idAttribute: “Id”, urlRoot: “/Items” });
- 15. Model var item = new Item(); item.set({ Name: “Nick” }); // trigger change item.save(); // trigger sync
- 17. Collection • A list of models. • Underscore methods.
- 18. Collection var Items = Backbone.Collection.extend({ model: Item, url: "/Items“ }); var items = new Items(); items.fetch(); // trigger reset items.comparator = function(item) { return item.get("Name"); }
- 20. View • Manipulates the DOM. • Delegates DOM events. • Has a Model / Collection.
- 22. View var ListView = Backbone.View.extend({ el: $("ul"), initialize: function() { this.collection.bind("reset", this.render, this); }, render: function() { this.collection.each(this.addItem, this); return this; },
- 23. addItem: function(item) { var itemView = new ItemView({ var ItemView = Backbone.View.extend({ model: item tagName: "li", }); render: function() { this.$el.append(itemView.el); this.$el.text(this.model.get("Name")); itemView.render(); return this; } } }); });
- 24. View var items = new Items(); var listView = new ListView({ collection: items }); items.fetch();
- 26. Template(Underscore.js) Compiles JavaScript templates into functions that can be evaluated for rendering. • Mustache • jQuery - tmpl
- 27. Template <script type = “text/template” id = “item-template” > <li><%= Name %></li> </script> var ItemView = Backbone.View.extend({ … template: _.template($("#item-template").html()), ... render: function() { this.$el.html(this.template(this.model.toJSON())); return this; } … });
- 28. Router • Maps urls to function. • Enable history / bookmarking. var AppRouter = Backbone.Router.extend({ routes: { "": "init" }, init: function() { … } });
- 29. Router window.AppRouter = Backbone.Router.extend({ routes: { "": "loadInvoices", "/add": "addInvoice", "/show/:id": "showInvoice", "/edit/:id": "editInvoice" }, loadInvoices: function() {… }, addInvoice: function() {… }, showInvoice: function(id) {… }, editInvoice: function(id) {… } });
- 31. Architecture
- 32. Jquery to Backbone.js $(document).ready(function() { $('#new-status form').submit(function(e) { e.preventDefault(); $.ajax({ url: '/status', type: 'POST', dataType: 'json', data: { text: $('#new-status').find('textarea').val() }, success: function(data) { $('#statuses').append('<li>' + data.text + '</li>'); $('#new-status').find('textarea').val(''); } }); }); });
- 33. Step to step from Jquery to var Status = Backbone.Model.extend({ Backbone.js url: '/status' }); var Statuses = Backbone.Collection.extend({ model: Status }); var NewStatusView = Backbone.View.extend({ events: { 'submit form': 'addStatus' }, initialize: function() { this.collection.on('add', this.clearInput, this); }, addStatus: function(e) { e.preventDefault(); this.collection.create({ text: this.$('textarea').val() }); }, clearInput: function() { this.$('textarea').val(''); } });
- 34. var StatusesView = Backbone.View.extend({ initialize: function() { this.collection.on('add', this.appendStatus, this); }, appendStatus: function(status) { this.$('ul').append('<li>' + status.escape('text') + '</li>'); } }); $(document).ready(function() { var statuses = new Statuses(); new NewStatusView({ el: $('#new-status'), collection: statuses }); new StatusesView({ el: $('#statuses'), collection: statuses }); });
- 35. Real World • DocumdentCloud • LinkedIn mobile • Pandora • Airbnb • Hulu • BaseCamp • Diaspora http://backbonejs.org/#examples
- 36. Resource • https://github.com/documentcloud/backbone /wiki • https://github.com/documentcloud/backbone /wiki/Extensions%2C-Plugins%2C-Resources • http://backbonetutorials.com/ • http://addyosmani.github.com/backbone- fundamentals/
- 37. Extra TDD – Jasmine http://pivotal.github.com/jasmine/ describe("Todo", function() { it("Should have a title", function() { var todo = new Todo(); expect(todo.get("title")).toBeDefined(); }); });
- 38. Pros and Cons + • Lightweight • Powerful • Code is clean(and maintainable) - • Too verbose(for small applications)