building a desktop streaming console with electron and reactjs

Building a Desktop Streaming console with

Electron and ReactJS

Playing with HTML, JS and CSS out of the sandbox

W W W. S P R E A K E R .C O M

Who am i?Emanuele Rampichini

• Software engineer @spreaker • JavaScript enthusiast • Github pusher on https://github.com/lele85 • “Not so active” tweeting bird @emauele_r • Mountain Bike Lover

https://github.com/lele85


Who are you?

• Software engineer @{companyName} • JavaScript enthusiasts • Github pushers on https://github.com/{{githubUsername}} • “{{very || notSo}} active” tweeting birds @{{twitterHandle}} • {{otherUnrelatedPassion}} Lover


Why are you here listening to me?

• You don’t know • You are not listening • You have to change 6 trains to get home, it’s gonna be a long way back so

you think that a 45 minutes nap is a good idea.

• You want to build a cross platform “Real World Desktop Application”™ using JavaScript


How much “Real World”™


“Use HTML, CSS, and JavaScript with Chromium

and Node.js to build your app.

nw.js or Electron?


Our winner was?

Faster, Stronger… Better (cit.)

npm install -g electron


package.json main_process

renderer_process


this looks very interesting given the state of modern frontend tools


basically you are writing a client app…

• ReactJS • SystemJS • JSPM • Babel • other libs (moment, underscore, emojione, url,

reconfig, analytics* etc…)


WHY React.js

• Unopinionated render engine for the DOM • Can be fast enough… try to do 16ms render loop

with angular bidirectional binding • Battle tested by Facebook


HOW React.js

• Multiple store single dispatcher flux architecture “for something" (USER ACTIONS, WEB API, PUSH NOTIFICATION)

• We rolled out our solution for specific tasks (EVENT EMITTERS, FINITE STATE MACHINES)


Why we used stateful components

• Sateless components are cool but sometimes you just need trade purity for performance


SystemJS + JSPMUniversal dynamic module loader - loads ES6 modules, AMD, CommonJS and global scripts in the browser and NodeJS. Works with both Traceur and Babel.

jspm is a package manager for the SystemJS universal module loader, built on top of the dynamic ES6 module loader


SystemJS• Unopinionated (not a client tool) • Understands dependencies tree • Dependencies versioning done right (can you hear

me npm?) • Can do client side transpiling* (keep an eye on

performance here) • Has an advanced bundler for production (transpiling,

minification, bundle arithmetic)


JSPM

• jspm init • jspm install • jspm bundle

You can have ES6 ready environment ready in two minutes*.

* Beware the automagic beast… could bite you :)

https://www.youtube.com/watch?v=NpMnRifyGyw

https://www.youtube.com/watch?v=NpMnRifyGyw


back to electron…you can use your loved chrome dev tools


…you can leverage desktop integration

• Menu • Notifications • Shortcuts • Multiple displays • …


you can go down a bit…RPC server to expose app API

use raw sockets


…you can get more from chromium

https://github.com/atom/electron/blob/master/docs/api/chrome-command-line-switches.md

http://peter.sh/experiments/chromium-command-line-switches/

https://github.com/atom/electron/blob/master/docs/api/chrome-command-line-switches.md

http://peter.sh/experiments/chromium-command-line-switches/


…or you can start digging “into the rabbit hole”

Electron is moving faaaast, use NaN to write add-ons, dynamic libs can give you headaches


…you can unit test inside the electron environment

https://github.com/lele85/karma-electron-launcher

https://github.com/lele85/karma-electron-launcher


…you have autoupdates out of the box*

* Works only with signed app, works in a different way on windows

Single script on a server returning

update zip uri and metadata


native crash reports are super easy to collect and test!

Every native crash (out of memory, segmentation faults) electron send a POST to configured submitUrl with:

platform informations memory dump in minidump format


… not so easy to decode :)For each version you deliver you need to get electron

debug symbols from project release pageGenerate symbols for your native libs with breakpad

tool dump_syms*Put them in a folder (with a standard structure) and use minidump_stackwalk* to symbolize them in a correct

way

* you can build these tools from break pad source tree


keep in mind something about desktop apps…

Given: 2 operating systems And: 10 os versions to support And: a lot of different hardware

And: a lot of USB devices someone can plug And: ∞ trash software common user can install

Then: YOUR APP WILL ALWAYS FAIL


…act accordingly

• gather all data you can on the host pc • log on filesystem (log4js, Dispatcher) • set up a server side issue reporting API • dont’t assume anything about application state when

something goes terribly wrong • monitor (universal analytics to the rescue)


you can add branding and package your app for mac and windows in a breeze

https://github.com/atom/grunt-electron-installer

https://github.com/maxogden/electron-packager


you can distribute your code in a “safe way”

Inside electron you can treat your asar bundle as a normal directory. (you may want to uglify/obfuscate your code)


all these things makes me very happy!


Sadly electron has some downsides…

• You are bundling Chromium with every update. compressed app size is around 40MB

• You can’t hit Mac App Store and Windows Marketplace

• Sometimes you have to dig into tools source code (this can be fun) and spend time on github project issue tracker


but…

• It worked for us • Makes desktop development fun • Makes desktop development fast.


It worked for us

• 22k downloads in 16 days • now 800 downloads per day • 25k sessions (mean time 1h 30m) • 11 releases delivered via autoupdate

(1.0.0 => 1.0.11)

Thanks!I broadcasted this talk to my colleagues

using the product we built :)


One more thing…

https://www.spreaker.com/jobs

https://www.spreaker.com/jobs

building a desktop streaming console with electron and reactjs

Engineering