All aboard the NodeJS Express

Get on board the NodeJS Express as we take a journey through what makes NodeJS special. Server-side JavaScript that has an event loop for a heart, we'll delve into its single threaded nature and the advantages provided. From there we'll pass through the land of the Node Package Management tool, how to set up your own package and bring in useful 3rd party packages as dependencies. Our final destination is ExpressJS, a Sinatra inspired framework for NodeJS.

Transcript

1. All aboard the Node.JS Express #SotR14
2. You know Node? Kev McCabe is covering TDD SotR14 - Mura Room
3. Who is this guy? David Boyer Senior Software Developer NHS Wales Informatics Service
4. ...and yes... that's me in the mask @ SotR13
5. Node.js A JavaScript runtime http://nodejs.org
6. The Details JavaScript Google's V8 engine Open Source - MIT License Cross platform Single threaded code Multi threaded IO
7. What can it do? Build web applications Creating command line tools Create desktop applications (node-webkit)
8. Who is using it? PayPal, LinkedIn, Yahoo, Microsoft, eBay, 37signals, LearnBoost, Yammer, Walmart
9. Node in detail
10. In the beginning... Install Command line
11. Action!* n o d e c o n s o l e . l o g ( ' H e l l o S c o t c h ' ) ;
12. Using the API v a r f s = r e q u i r e ( ' f s ' ) ; / / F i l e s y s t e m A P I v a r h t t p = r e q u i r e ( ' h t t p ' ) ; / / h t t p A P I v a r c r y p t o = r e q u i r e ( ' c r y p t o ' ) ; / / C r y p t o A P I
13. One thread to rule them all! One thread for JavaScript Multiple threads for I/O
14. The Event Loop Event Queue Single js thread Multiple I/O Threads    
15. What does the code look like? v a r f s = r e q u i r e ( ' f s ' ) ; v a r r a w D a t a = f s . r e a d F i l e S y n c ( ' s o t r . j s o n ' ) ; v a r d a t a = J S O N . p a r s e ( r a w D a t a ) ; c o n s o l e . l o g ( n e w D a t e ( ) ) ; c o n s o l e . l o g ( d a t a . m e s s a g e ) ;
16. Why not just be multi- threaded? Each thread needs more memory Switching between threads costs CPU Avoids thread safety issues
17. Scaling single threads The Cluster API ↗  ⇶  →  ↘ 
18. v a r c l u s t e r = r e q u i r e ( ' c l u s t e r ' ) ; v a r h t t p = r e q u i r e ( ' h t t p ' ) ; v a r c p u s = r e q u i r e ( ' o s ' ) . c p u s ( ) . l e n g t h ; i f ( c l u s t e r . i s M a s t e r ) { f o r ( v a r i = 0 ; i < c p u s ; i + + ) { c l u s t e r . f o r k ( ) ; } c l u s t e r . o n ( ' e x i t ' , f u n c t i o n ( w o r k e r , c o d e , s i g n a l c o n s o l e . l o g ( ' P r o c e s s I D ' + w o r k e r . p r o c e s s . p i d } ) ; } e l s e { h t t p . c r e a t e S e r v e r ( f u n c t i o n ( r e q , r e s ) { . . . } ) . l i s t }
19. Switching mindset From sync to async Lots of callbacks Callback Hell!
20. Highway to Hell f s . r e a d F i l e ( ' s o t r . j s o n ' , f u n c t i o n ( e r r , d a t a ) { v a r i n f o = J S O N . p a r s e ( d a t a ) ; d b . f i n d O n e ( { i d : i n f o . i d } , f u n c t i o n ( e r r , r e c o r d ) f s . w r i t e F i l e ( ' s o t r . d a t ' , r e c o r d . t i t l e , f u n c t i o c o n s o l e . l o g ( ' F i n i s h j o b ' ) ; } ) } ) } )
21. Escape from Nested Callbacks Break it apart Use a async module like "async" Promises Generators (ES6)
22. Node as a web application v a r h t t p = r e q u i r e ( ' h t t p ' ) ; v a r s e r v e r = h t t p . c r e a t e S e r v e r ( f u n c t i o n ( r e q , r e s ) r e s . e n d ( ' H e l l o S c o t c h ! ' ) ; } ) ; s e r v e r . l i s t e n ( 8 0 ) ;
23. Modules / / c o n f . j s f u n c t i o n C o n f e r e n c e ( n a m e , y e a r ) { t h i s . n a m e = n a m e ; t h i s . y e a r = y e a r ; } ; C o n f e r e n c e . p r o t o t y p e . g e t T i t l e = f u n c t i o n ( ) { r e t u r n t h i s . n a m e + ' ' + t h i s . y e a r ; } ; m o d u l e . e x p o r t s = C o n f e r e n c e / / i n d e x . j s v a r C o n f = r e q u i r e ( _ _ d i r n a m e + ' / c o n f . j s ' ) ; v a r s o t r = n e w C o n f ( ' S c o t c h o n t h e R o c k s ' , 2 0 1 4 ) ; c o n s o l e . l o g ( s o t r . g e t T i t l e ( ) ) ;
24. npm The Node.js Package Manager
25. Initialise your project n p m i n i t n a m e : ( c o n f e r e n c e ) s o t r - e x a m p l e v e r s i o n : ( 0 . 0 . 0 ) 0 . 1 . 2 d e s c r i p t i o n : A n e x a m p l e p r o j e c t e n t r y p o i n t : ( i n d e x . j s ) i n d e x . j s t e s t c o m m a n d : g r u n t n o d e u n i t g i t r e p o s i t o r y : g i t : / / g i t h u b . c o m / m i s t e r d a i / i s n o t a . k e y w o r d s : e x a m p l e , a p p a u t h o r : D a v i d B o y e r l i c e n s e : ( B S D - 2 - C l a u s e ) M I T
26. Finding modules https://npmjs.org https://nodejsmodules.org/ http://eirikb.github.io/nipster/
27. Common modules Databases: mysql, mongodb, sqlite Callbacks: async, q, when, co Testing: Mocha, nodeunit, should Templating: Jade, handlebars, ejs Web frameworks: express,
28. Installing modules n p m i n s t a l l a s y n c n p m i n s t a l l - - s a v e c o f f e e - s c r i p t n p m i n s t a l l - - s a v e - d e v g r u n t - i m a g e m i n n p m i n s t a l l n p m u n i n s t a l l - - s a v e c o f f e e - s c r i p t
29. Installing commands n p m i n s t a l l - g c o f f e e - s c r i p t n p m u n i n s t a l l - g g r u n t - c l i n p m i n s t a l l - g g u l p
30. Other npm super powers Publish modules Execute scripts (e.g. npm build, npm run) Bump your version number (semver)
31. Summary Let npm manage your modules Use it to install useful tools such as grunt Don't have to keep node_modules in source control Store project related commands in package.json
32. Express yourself Express, a web framework for Node.js Very flexible Minimal
33. Version 4 Bundled middleware are now their own modules*. * Except "static". More robust routing. a p p . r o u t e r ( ) is gone and more flexible methods are now available.
34. Installing m k d i r w e b s i t e c d w e b s i t e n p m i n i t n p m i n s t a l l - - s a v e e x p r e s s t o u c h i n d e x . j s
35. A static site Serving static files from a directory
36. A dynamic site JavaScript providing the content
37. A template engine https://github.com/visionmedia/consoli Jade, EJS (Embedded JavaScript), Handlebars...
38. Try being MEAN!  Popular stack for building Node.js based web apps. MongoDB E xpress AngularJS Node.js
39. Thanks for listening to my first ever conference talk
40. Questions  If we have time... ...or catch me at the bar .
41. GAME  OVER All aboard the NodeJS Express David "Mister Dai" Boyer  @misterdai