/examples/todos/todos.js
JavaScript | 245 lines | 134 code | 53 blank | 58 comment | 10 complexity | cc411067d8562bb0abdc98a37176422a MD5 | raw file
- // 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
- };
- },
- // Ensure that each todo created has `title`.
- initialize: function() {
- if (!this.get("title")) {
- this.set({"title": this.defaults().title});
- }
- },
- // Toggle the `done` state of this todo item.
- toggle: function() {
- this.save({done: !this.get("done")});
- },
- // Remove this Todo from *localStorage* and delete its view.
- clear: function() {
- this.destroy();
- }
- });
- // 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"` namespace.
- localStorage: new Store("todos-backbone"),
- // Filter down the list of all todo items that are finished.
- done: function() {
- return this.filter(function(todo){ return todo.get('done'); });
- },
- // Filter down the list to only todo items that are still not finished.
- remaining: function() {
- return this.without.apply(this, this.done());
- },
- // 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: function(todo) {
- return todo.get('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.model.on('change', this.render, this);
- this.model.on('destroy', this.remove, this);
- },
- // 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();
- 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.clear();
- }
- });
- // 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];
- Todos.on('add', this.addOne, this);
- Todos.on('reset', this.addAll, this);
- Todos.on('all', this.render, this);
- 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);
- },
- // 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() {
- _.each(Todos.done(), function(todo){ todo.clear(); });
- 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;
- });