WAY

ARCHITECTTHE

Jan JongboomJSCamp.asia

November 30, 2012, Singapore

@janjongboom

Program

• Cloud9? 5 minute intro + what's new

• Problems growing your codebase

• Introducing: Architect!

• Lessons learned

Normal developers

JavaScript Developer

OPPA CLOUD9 STYLE

Smart code completion

Static analysis

Free Linux machine

Real terminal

Program

• Cloud9? 5 minute intro + what's new

• Problems growing your codebase

• Introducing: Architect!

• Lessons learned

Hundreds of thousands of lines of JavaScript

(with semicolons ;-))

dynamicweakly-typedlanguage

one single thread

Modularization

Black box coding

Great at abstracting away

Not that good at app level abstraction

Relies on filesystem

• Duplicated modules

• Maps to folder / file name

• Hard to configure

coding time startup time run time

KA-BO

OM!

- Server crash- Unhappy customers- Developer gets fired

Dependency error handling

Program

• Cloud9? 5 minute intro + what's new

• Problems growing your codebase

• Introducing: Architect!

• Lessons learned

Architect

• Every piece of functionality is a plugin

• Plugins can consume other plugins

• An application is a set of plugins

Require

Architect

Runtime

Startup time

Dependency error handlingArchitect style

coding time compile time run time

- Happy customers- Developer keeps job- Fails before release

Here’s what we do

• Code representation of this talk

• Get a speaker from the database

• Talk, talk, talk

• And end with a dance

Group functions by behavior

Datalayer

Presentation

Datalayer Presentation

Dependency model

package.json

Builds dependency tree

executing codewithout

data-­‐layer/package.json

presentation/package.json

What’s next?

• Extract the code

• Wrap in Architect plugin code

• It’s simple!

• Make two plugins

Function signature

Call when done

Architect plugin code

• Options, will get to that

• Imports, everything you consume

• Register, invoke when done

Dependencies abstracted away

• Easily unit testable

• Mock dependencies

• Assert ‘talk’ function is called 5 times

No black magic

• Architect builds dependency model

• Feed architect a list of plugins

• Simple array with file names

• Call ‘createApp’

Configuration

• Per-plugin options

• No global options object

• Specify in config file

Options

• Automatically passed in at startup

• Options are also dependencies

• Fail if options aren’t present

• Use default assertions

Architect makes you think of your app as

chunks of functionalityrather than sets of classes

Think ‘chunks of functionality’

• Implicit type constraints

• Keep implementation private

• Swap feature implementations

• Rather than interface implementations

How do we use it?

• Open source version

• Hosted version

• Normal

• FTP

• SSH

Swap feature per implementation

• On Open source: talk local filesystem

• On FTP: talk FTP library

• On SSH: log in and talk via a SSH bridge

HERE’S SOMETHING COOL

Centralized eventbus

• Loose coupling between plugins

• No hard dependencies!

• Can also do inter-context communication

Eventbus

Plugin

Other plugin

Emit event

React on event

And now scale up

• Need something inter-server

• Swap it with i.e. Redis PubSub

• Plugins will never notice

• Awesome!

Program

• Cloud9? 5 minute intro + what's new

• Problems growing your codebase

• Introducing: Architect!

• Lessons learned

Modularize in feature blocks

• Don’t over engineer

• Don’t create too small blocks

• They are no interfaces!

Avoid context switching

• Less code!

• Less errors!

• Less boilerplate!

Loose coupling

• Eventbus

• Smaller dependency graph

github.com/c9/architect

Happy coding!

Jan Jongboomgithub.com/janjongboom

@janjongboom

http://c9.io