Introduction to Backbone.js in WordPress

Brian Hoggbrianhogg.com | @brianhogg

WordCamp Ann Arbor 2015

brianhogg.com

Subtitle

Section Divider Title LayoutSubtitle

Event Calendar Newsletter

https://wordpress.org/plugins/event-calendar-newsletter/

Agenda▪ Why Backbone.js▪ Basics of Backbone.js / Underscore.js▪ Example plugin using wp.template, wp.Backbone.View and WP JSON

REST API v2

Who are you?

Why Backbone.js vs just jQuery?▪ Events system▪ Performance▪ Leveraging the community▪ Not re-inventing the wheel▪ Enforces some structure on your JavaScript code

Backbone.js has an MV* structureUses jQuery but only hard requirement is Underscore.js

What is Underscore.js?Utility functions with _

_.each, _.template, Lots more: http://documentcloud.github.io/underscore/

Templatesvar template = _.template("hello <%= name %>");var html = template({ name: 'Brian' });console.log( html ); // "hello Brian"

var template = _.template("<strong><%- value %></strong>");var html = template({ value: '<script>' });console.log( html ); // "<strong>&lt;script&gt;</strong>"

Templatesvar template = _.template("hello <%= name %>");var html = template({ name: 'Brian' });console.log( html ); // "hello Brian”

var template = _.template("<strong><%- value %></strong>");var html = template({ value: '<script>' });console.log( html ); // "<strong>&lt;script&gt;</strong>"

wp.template

wp.template

hello {{ name }}

<strong>{{{ value }}}</strong>

hello <%= name %>

<strong><%- value %></strong>

wp.template

<# if ( some_condition ) { #>some output

<# } #>

Lots of AlternativesEmber.JS, Angular.JS, ...

Multiple ways of doing similar things. Even in Backbone.JS:

“It's common for folks just getting started to treat the examples listed on this page as some sort of gospel truth. In fact, Backbone.js is intended to be fairly agnostic about many common patterns in client-side code.” http://backbonejs.org/#FAQ-tim-toady

Backbone / Underscore

Included in WordPress since 3.5

The "backbone" of the media manager, revisions UI

Models

“Models are the heart of any JavaScript application, containing the interactive data as well as a large part of the logic surrounding it: conversions, validations, computed properties, and access control. You extend Backbone.Model with your domain-specific methods, and Model provides a basic set of functionality for managing changes.”

Models Examplevar Post = Backbone.Model.extend({

defaults: {title: "",post_status: "draft"

},

initialize: function() { console.log("creating a post");

} });

var post = new Post({ title: "Hello, world", post_status: "draft" });var title = post.get("title"); // Hello, worldvar post_status = post.get("post_status"); // draft

Listening for Changes

post.on("change:title", function(model) { alert("Title changed to: " + model.get("title"));

});

this.on("change:title", this.titleChanged)

or in the initialize function of a model with:

Views▪ Used to turn a model into something you can see▪ Always contains a DOM element (the el property) though it may not

have been added to the viewable page yet

Bare Minimum to use BackboneGroup your events code together

var PostView = Backbone.View.extend({ events: {

"click .edit": "editPost","change .post_status": "statusChanged"

},editPost: function(event) {

// ...},statusChanged: function(event) {

// ...}

});

var postView = new PostView({ el: '#my-form' });

wp.template<script id="tmpl-bb-post" type="text/html">

{{{ data.title }}}</script>

bbdemo.PostView = wp.Backbone.View.extend({template: wp.template(‘bb-post'),

prepare: function() {return this.model.toJSON();

}});

Collections

Ordered set of modelsvar Posts = Backbone.Collection.extend({

model: Post});var post1 = new Post({ title: "Hello, world" });var post2 = new Post({ title: "Sample page" });var myPosts = new Posts([ post1, post2 ]);

Populating Collection from ServerWP REST API

[{

id: 1,title: {

rendered: "Hello, World"}

},{

id: 3,title: {

rendered: "Ann Arbor is amazing"}

},]</script>

Populating Collections from Server

var Posts = Backbone.Collection.extend({ model: Post,url: bbdemo.url + '/posts'

});

var postsCollection = new Posts();postsCollection.fetch();

If not a RESTful format, would need to override functions like fetch, sync and parse

How Backbone Works With REST APIs

Out of the box, Backbone.js supports RESTful APIs through Backbone.sync():

create → POST /collectionread → GET /collection[/id]update → PUT /collection/idpatch → PATCH /collection/iddelete → DELETE /collection/id

DEMO

ResourcesWP API JavaScript Clienthttps://github.com/WP-API/client-js

Backbone Debugger for Chromehttps://chrome.google.com/webstore/detail/backbone-debugger/bhljhndlimiafopmmhjlgfpnnchjjbhd?hl=en

Example wp.Backbone.View pluginhttps://github.com/markjaquith/Showdown

Code / Slideshttps://github.com/brianhogghttp://www.slideshare.net/bhogg

Introduction to Backbone.js in WordPress

Brian Hoggbrianhogg.com | @brianhogg

WordCamp Ann Arbor 2015