Master Class:Isomorphic JavaScript

Spike Brehm@spikebrehm

New iOS, Android apps launched today

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Agenda

...TF is Isomorphic JavaScript?Wat

...is it relevant to web developers?Wy

...can I build isomorphic apps?How

WTF is Isomorphic JavaScript?

JavaScript code that can run on both the client and server.

A brief note on “isomorphic”.

“monomorphic”“heteromorphic”“homomorphic”“multi-platform”

You’re using it wrong!

Example, plz.

Example: Underscore.js

var posts = [{ id: 1, title: 'JavaScript is cool'}, { id: 2, title: 'The Web is the platform'}]; _.pluck(posts, 'title');// ['JavaScript is cool', 'The Web is the platform']

Ye olde days:fat-serer, thin-client.

ClientJavaScript

SererRubyPythonJavaPHP

Persistence

View layer

Application logic

Routing

DOM manipulation

Form validation

Animations

Circa 2011:thin-serer, fat-client.

Routing

View layer

SererRubyPythonJavaPHP

Persistence

ClientJavaScript

Application logic

DOM manipulation

Form validation

Animations

Teh footure:shared, fat-serer, fat-client.

SererRubyPythonJavaPHP

Persistence

ClientJavaScript

Routing

View layer

Application logic

DOM manipulation

Form validation

SharedJavaScript

Animations

Isomorphic JavaScript can be

orshimmed per environment .

environment-agnostic

Does not depend on browser-specific properties (window) or server-specific properties (process.env, req.cookies).

Environment-agnostic

Example: Handlebars.js

var template = '<ul>' \ '{{#each posts}}' \ ' <li>{{title}}</li>' \ '{{/each}}' \ '</ul>'; var templateFn = Handlebars.compile(template) , html = templateFn({posts: posts}); // <ul>// <li>JavaScript is cool</li>// <li>The Web is the platform</li>// </ul>

Provides shims for accessing environment-specific properties so module can expose a single API.

window.location.pathnamevs.req.path

Shimmed per environment

Example: Superagent

superagent .post('/api/posts.json') .send({ title: 'Moar JavaScript', body: '...' }) .set('X-Api-KEY', '123456abcdef') .end(function(response) { if (response.status === 200) { console.log("Success!"); } else { console.error("Error", response.body.error); } });

Isomorphic use cases.

• Templating• Routing• I18n• Date & currency formatting• Model validation• API interaction• ...?

Isomorphic use cases.

Most of your favorite libraries can be used isomorphically.

• Underscore.js• Backbone.js• Handlebars.js• jQuery• Moment• React.js• Polyglot.js (I18n)

Isomorphic JavaScript is a spectrum.

Entire view layer and app

logic shared

Small bits of view layer or logic shared

Many abstractions

Few abstractions

ComplexSimple

View layer shared

Entire app runtime synced between client

& server

Wy go to the trouble?

Initial pageload speed.Performance

Crawlable single-page apps.SEO

Reduce code duplication.Maintainability

Building and bundling.

Package up CommonJS modules for the browser.

Browserif

Use ‘require()’ in the browser, the same way you would on the server.

// app/template_renderer.js var handlebars = require('handlebars'); module.exports = function(templatePath, data) { var templateFn = require('./views/' + templatePath) , html = templateFn(data); return html;};

Bundles a module and all its dependencies.

Browserif

Task runner for automating build and development workflow.

Grunt

•Compile Handlebars templates•Run Browserify to package up your shared app files

•Recompile files and restart Node server on every change

Grunt

Any questions thus far?

Hack time.

Combines a few modules together for MVP of isomorphic app.

Sample Node.js app

Express.js blog platformBasic web server with RESTful API.

Templating.Handlebars.js

DirectorRouting HTTP and HTML5.

HTTP requests to API.Superagent

Tour of the app.

Setting up locally.

git clone git@github.com:spikebrehm/isomorphic-tutorial.git

Clone the sample app

github.com/spikebrehm/isomorphic-tutorial

Ensure Node >= 0.8.x$ node --versionv0.10.21

github.com/spikebrehm/isomorphic-tutorial

Have to install?$ brew install nodeorhttp://nodejs.org

$ npm install grunt-cli -g

Install `grunt-cli`

github.com/spikebrehm/isomorphic-tutorial

$ cd isomorphic-tutorial$ npm install

Run `npm install`

github.com/spikebrehm/isomorphic-tutorial

$ grunt server

Run the serer!

github.com/spikebrehm/isomorphic-tutorial

View `localhost:3030` in browser

Let’s add a feature.

Date formattingBefore:After:

Momentmoment('2013-11-04T17:23:01.329Z').format('LLLL');// "Monday, November 4 2013 9:23 AM"

Add Moment using NPM$ npm install moment --save

Create `formatDate` Handlebars helperPosted at {{created_at}}

Posted at {{formatDate created_at}}

function formatDate(dateStr) { return moment(dateStr).format('LLLL');}

Questions?

@AirbnbNerds@spikebrehm

Thanks!