[转]backbone.js 示例 todos
本文转自：http://www.css88.com/doc/backbone/examples/todos/index.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>Backbone.js Todos</title> <link rel="stylesheet" href="todos.css"/> </head> <body> <div id="todoapp"> <header> <h1>Todos</h1> <input id="new-todo" type="text" placeholder="What needs to be done?"> </header> <section id="main"> <input id="toggle-all" type="checkbox"> <label for="toggle-all">Mark all as complete</label> <ul id="todo-list"></ul> </section> <footer> <a id="clear-completed">Clear completed</a> <div id="todo-count"></div> </footer> </div> <div id="instructions"> Double-click to edit a todo. </div> <div id="credits"> Created by <br /> <a href="http://jgn.me/">Jérôme Gravel-Niquet</a>. <br />Rewritten by: <a href="http://addyosmani.github.com/todomvc">TodoMVC</a>. </div> <script src="../../test/vendor/json2.js"></script> <script src="../../test/vendor/jquery.js"></script> <script src="../../test/vendor/underscore.js"></script> <script src="../../backbone.js"></script> <script src="../backbone.localStorage.js"></script> <script src="todos.js"></script> <!-- Templates --> <script type="text/template" id="item-template"> <div class="view"> <input class="toggle" type="checkbox" <%= done ? 'checked="checked"' : '' %> /> <label><%- title %></label> <a class="destroy"></a> </div> <input class="edit" type="text" value="<%- title %>" /> </script> <script type="text/template" id="stats-template"> <% if (done) { %> <a id="clear-completed">Clear <%= done %> completed <%= done == 1 ? 'item' : 'items' %></a> <% } %> <div class="todo-count"><b><%= remaining %></b> <%= remaining == 1 ? 'item' : 'items' %> left</div> </script> </body> </html>
// An example Backbone application contributed by // [Jérôme Gravel-Niquet](http://jgn.me/). This demo uses a simple // [LocalStorage adapter](backbone-localstorage.html) // to persist Backbone models within your browser. // Load the application once the DOM is ready, using `jQuery.ready`: $(function(){ // Todo Model // ---------- // Our basic **Todo** model has `title`, `order`, and `done` attributes. var Todo = Backbone.Model.extend({ // Default attributes for the todo item. defaults: function() { return { title: "empty todo...", order: Todos.nextOrder(), done: false }; }, // Toggle the `done` state of this todo item. toggle: function() { this.save({done: !this.get("done")}); } }); // Todo Collection // --------------- // The collection of todos is backed by *localStorage* instead of a remote // server. var TodoList = Backbone.Collection.extend({ // Reference to this collection's model. model: Todo, // Save all of the todo items under the `"todos-backbone"` namespace. localStorage: new Backbone.LocalStorage("todos-backbone"), // Filter down the list of all todo items that are finished. done: function() { return this.where({done: true}); }, // Filter down the list to only todo items that are still not finished. remaining: function() { return this.where({done: false}); }, // We keep the Todos in sequential order, despite being saved by unordered // GUID in the database. This generates the next order number for new items. nextOrder: function() { if (!this.length) return 1; return this.last().get('order') + 1; }, // Todos are sorted by their original insertion order. comparator: 'order' }); // Create our global collection of **Todos**. var Todos = new TodoList; // Todo Item View // -------------- // The DOM element for a todo item... var TodoView = Backbone.View.extend({ //... is a list tag. tagName: "li", // Cache the template function for a single item. template: _.template($('#item-template').html()), // The DOM events specific to an item. events: { "click .toggle" : "toggleDone", "dblclick .view" : "edit", "click a.destroy" : "clear", "keypress .edit" : "updateOnEnter", "blur .edit" : "close" }, // The TodoView listens for changes to its model, re-rendering. Since there's // a one-to-one correspondence between a **Todo** and a **TodoView** in this // app, we set a direct reference on the model for convenience. initialize: function() { this.listenTo(this.model, 'change', this.render); this.listenTo(this.model, 'destroy', this.remove); }, // Re-render the titles of the todo item. render: function() { this.$el.html(this.template(this.model.toJSON())); this.$el.toggleClass('done', this.model.get('done')); this.input = this.$('.edit'); return this; }, // Toggle the `"done"` state of the model. toggleDone: function() { this.model.toggle(); }, // Switch this view into `"editing"` mode, displaying the input field. edit: function() { this.$el.addClass("editing"); this.input.focus(); }, // Close the `"editing"` mode, saving changes to the todo. close: function() { var value = this.input.val(); if (!value) { this.clear(); } else { this.model.save({title: value}); this.$el.removeClass("editing"); } }, // If you hit `enter`, we're through editing the item. updateOnEnter: function(e) { if (e.keyCode == 13) this.close(); }, // Remove the item, destroy the model. clear: function() { this.model.destroy(); } }); // The Application // --------------- // Our overall **AppView** is the top-level piece of UI. var AppView = Backbone.View.extend({ // Instead of generating a new element, bind to the existing skeleton of // the App already present in the HTML. el: $("#todoapp"), // Our template for the line of statistics at the bottom of the app. statsTemplate: _.template($('#stats-template').html()), // Delegated events for creating new items, and clearing completed ones. events: { "keypress #new-todo": "createOnEnter", "click #clear-completed": "clearCompleted", "click #toggle-all": "toggleAllComplete" }, // At initialization we bind to the relevant events on the `Todos` // collection, when items are added or changed. Kick things off by // loading any preexisting todos that might be saved in *localStorage*. initialize: function() { this.input = this.$("#new-todo"); this.allCheckbox = this.$("#toggle-all")[0]; this.listenTo(Todos, 'add', this.addOne); this.listenTo(Todos, 'reset', this.addAll); this.listenTo(Todos, 'all', this.render); this.footer = this.$('footer'); this.main = $('#main'); Todos.fetch(); }, // Re-rendering the App just means refreshing the statistics -- the rest // of the app doesn't change. render: function() { var done = Todos.done().length; var remaining = Todos.remaining().length; if (Todos.length) { this.main.show(); this.footer.show(); this.footer.html(this.statsTemplate({done: done, remaining: remaining})); } else { this.main.hide(); this.footer.hide(); } this.allCheckbox.checked = !remaining; }, // Add a single todo item to the list by creating a view for it, and // appending its element to the `<ul>`. addOne: function(todo) { var view = new TodoView({model: todo}); this.$("#todo-list").append(view.render().el); }, // Add all items in the **Todos** collection at once. addAll: function() { Todos.each(this.addOne, this); }, // If you hit return in the main input field, create new **Todo** model, // persisting it to *localStorage*. createOnEnter: function(e) { if (e.keyCode != 13) return; if (!this.input.val()) return; Todos.create({title: this.input.val()}); this.input.val(''); }, // Clear all done todo items, destroying their models. clearCompleted: function() { _.invoke(Todos.done(), 'destroy'); return false; }, toggleAllComplete: function () { var done = this.allCheckbox.checked; Todos.each(function (todo) { todo.save({'done': done}); }); } }); // Finally, we kick things off by creating the **App**. var App = new AppView; });