JavaScript has evolved from being seen as a joke to becoming a serious programming language used to build large web applications. It started as a scripting language for web browsers but is now used widely on both the client-side and server-side. The JavaScript ecosystem is very active with many libraries, frameworks, and tools available to help developers build and test applications.

1. There is something about
JavaScript
Mail: jonas.bandi@gmail.com
Twitter: @jbandi

2. D
Jonas Bandi
5 Years ago I had no
clue about JavaScript
Today JavaScript pays my bills

3. My Journey into JavaScript Land

4. I went through the five
stages of grief.

5. Denial

7. Fear

8. Repulsion

9. Curiosity

12. Most of the people writing in JavaScript are not programmers.
They lack the training and discipline to write good programs.
- Douglas Crockford, 2001
A very large group of developers still thinks of JavaScript as a
joke.
- Davy Brion, 2011
We strongly suggest to adopt JavaScript as a first class language.
- ThoughtWorks Technology Radar, 2011
The ecosystem around JavaScript as a serious application
platform continues to evolve.
- ThoughtWorks Technology Radar, January 2014
Through 2014, improved JavaScript performance will begin to
push HTML5 and the browser as a mainstream enterprise
application development environment.
- Gartner, October 2013

13. Two Worlds?

14. Any application that can be written in
JavaScript, will eventually be written
in JavaScript.
- Atwood’s Law, 2007

15. We are slaves to JavaScript because
people have simply started to accept
its weirdness and flaws, much like a
Stockholm Syndrome phenomenon.
- Chris Richardson, 2013

16. The Language

17. The Bad Parts

18. 18 Powerful Parts

19. GWT
is
a
reasonable
implementaDon
of
a
poor
architectural
choice.
GWT
a$empts
to
hide
many
of
the
details
of
the
web
as
a
plaForm
by
creaDng
desktop
metaphors
in
Java
and
generaDng
JavaScript
code
to
implement
them.
First,
in
many
ways,
JavaScript
is
more
powerful
and
expressive
than
Java,
so
we
suspect
that
the
generaDon
is
going
in
the
wrong
direcDon.
h$p://www.ThoughtWorks
Technology
Radar,
July
2011 thoughtworks.com/radar

20. var add = function(first, second) {
return first + second;
};
var splitCall = function(first, func){
return function(second){
return func(first, second);
}
}
var addOne = splitCall(1, add);
addOne(22); // -> 23

21. JavaScript != Java

22. History
• HyperCard
for
the
browser
Brendan
Eich
(ex
CEO
of
Mozilla)
• Make
it
look
like
Java!
• Completed
in
10
days
h$p://javascriptjabber.com/124-­‐jsj-­‐the-­‐origin-­‐of-­‐javascript-­‐with-­‐brendan-­‐eich/

23. Language Constructs
• Object
• Class
• Method
• Constructor
• Packages
• Inheritance
• Object
• Function
...everything else can
be implemented

24. Closures

25. Elegant Parts

26. Ecosystem

27. Language
Libraries / Frameworks
dependency management
Write Code
Build Test
Deploy
IDE
Toolset
compile
package Test-Frameworks

28. Language
Libraries / Frameworks
dependency management
Write Code
Build Test
Deploy
IDE
Bower
Toolset
compile
package Test-Frameworks

29. Toolset

31. Bower

32. Building

33. PROJECT BUILD
Compile
Package
Develop
(IDE)
Build jar, war,
assembly
Backend
(Java, .NET)
Deploy Test
… into a container
(Tomcat, JBoss, IIS …) execute
Linting
Package
Frontend
(JavaScript)
Develop
(Editor, IDE)
Minification,
Concatenation, Revision
Deploy Test
copy to directory execute in browser

34. Testing

35. Dependency
Management

36. Eco-Mess?

37. Frontend Libraries & Frameworks

38. Jake
JavaScript build
Tool similar to
Rake or Make.
Broccoli
Bower
Build Tools

39. Testing Tools
Testem A test runner that makes
Javascript unit testing fun.

40. ACTIVE ECOSYSTEM
• 109 000 Node Packages on www.npmjs.org
(Maven Central has 806'000 artifacts)

42. Big Momentum

43. JavaScript is the Language of the Web.
Another software technology will come
along and kill off the web. That judgement
day will arrive very soon.
-Forrester Research in 2000
The Web has won!

44. HTML 5
HTML5 explained:
• Html is the structure
• CSS is the colour and
style
• JavaScript is everything
else
Scott Hanselman: Angle Brackets, Curly Braces http://channel9.msdn.com/Events/Build/2012/3-027

45. It's everywhere!
Nashorn

46. http://redmonk.com/dberkholz/2014/05/02/github-language-trends-and-the-fragmenting-landscape/

47. LARGE JAVASCRIPT APPLICATIONS
? LoC
? LoC
? LoC

48. LARGE JAVASCRIPT APPLICATIONS
400’000 LoC (2012)
300’000 LoC (2012)
200’000 LoC (2013)

49. Potential Sweet Spots

50. SPA Architecture
View
Model
Controller
"object model"
Services
Client Server
clear boundary
• Rich client
programming model in
the browser
• Clear separation of
concern between
client and server

51. Sharing Logic between
Client and Server
• Full-Stack JavaScript
www.meteor.com
• Run JavaScript logic on
traditional Java / .NET
backend
• Validation
•Workflow / Scripting
View
Controller
Client Server
Business Logic "Code
Repository"
Model

52. Discussions?