Express on Rails

Have you built your first node application yet? Yeah, me too! Wasn't writing it fun and easy? Same here! Did your codebase quickly turn into an unrefactorable soupy mess too? Of course it did!

In this talk, we'll discuss the architectural and organizational strategies used by Ruby on Rails that help the scope and size of applications to scale easily. We'll then learn how we can easily employ those principles with express.js to build some serious node applications, without all the dogmatism and pain that usually comes with RoR.

Transcript

1. Emergency alternative topics included:
2. Hilariously Incorrect Assertions About ES5
3. Literally Reading Aloud From The W3C Spec For CSS Selectors
4. Why Are You Still Using Semicolons? (Or, How To Piss Off The First Kyle In 15 Slides Or Less)
5. Here's A 0-Day IE8 JS Bug And We Should Really Just Stop Targeting It Now
6. Playing That Game For 30 Minutes "You Can't JavaScript Under Pressure"
7. Express on Rails Kyle Hill kyle@jibe.com NationJS 2013 @kylehill
8. Fun
9. Programming should be fun
10. Fun = creativity
14. Fun = creativity + quality
18. An inflexible " " = masterpiece drilling holes for fig leaf hooks
19. "we have come to value [...] over following a plan" responding to change -- The Agile Manifesto
20. "Defer decision-making until the last moment." responsible -- Yehuda Katz
21. Rails is a framework which is built for Agile
22. Test-driven Development
23. Don't Repeat Yourself
24. Convention over Configuration
25. Rails patterns for eventual decisions dictates
26. Don't fight The Rails Way
27. Programming should be fun
28. Rails is a which is built for Agile framework
29. Frameworks aren't creative Frameworks are plumbing
30. Rails is an which is built for Agile opinionated, frameworky framework
33. Rails is a framework which is at doing what it wants to do exceptionally good
34. Rails has , but. quality
35. node
36. "I started playing with node and was just setting up sockets and listeners and content types, and I was like, 'whoa.' It was awesome." -- the masochistic Rails dev I work with
37. node → Express
38. Express is a framework which is built for... whatever
39. You can't reasonably fight Express
40. Q: "How should I structure my application?" A: "There is no true answer to this question, it is highly dependent on the scale of your application and the team involved. To be as flexible as possible Express makes no assumptions in terms of structure." -- express.js FAQ
41. All configuration No convention
42. Fun...?
43. Fun = creativity + quality
44. app.js // everyone's first node app v a r a p p = r e q u i r e ( ' e x p r e s s ' ) . c r e a t e S e r v e r ( ) ; v a r a s y n c = r e q u i r e ( ' a s y n c ' ) ; v a r r e q u e s t = r e q u i r e ( ' r e q u e s t ' ) ; v a r p a r s e r = r e q u i r e ( ' x m l 2 j s o n ' ) ; v a r u n d e r s c o r e = r e q u i r e ( ' u n d e r s c o r e ' ) ; v a r m o n g o d b = r e q u i r e ( " m o n g o d b " ) ; a p p . g e t ( ' / m e t h o d / s t a t i o n / : i d ' , f u n c t i o n ( r e q , r e s ) { r e q u e s t ( { u r i : ' h t t p : / / ' + r e q . h e a d e r s . h o s t + ' / s t a t i o n l i s t ' , j s o n : t r u e } , r e s . j s o n ( u n d e r s c o r e . f i n d ( b o d y . s t a t i o n s . s t a t i o n , f u n c t i o n ( s ) { r e t u r n s . t e r } ) ; } ) ; a p p . g e t ( ' / m e t h o d / s t a t i o n l i s t ' , f u n c t i o n ( r e q , r e s ) { a s y n c . a u t o ( { g e t X m l : f u n c t i o n ( c a l l b a c k ) { r e q u e s t ( ' h t t p : / / c a p i t a l b i k e s h a r e . c o m / d a t a / s t a t i o n s / b i k e S t a t i o n s . x m l ' , f c a l l b a c k ( n u l l , p a r s e r . t o J s o n ( b o d y , { o b j e c t : t r u e } ) ) ; } ) ; } , d o S t u f f : [ ' g e t X m l ' , f u n c t i o n ( c a l l b a c k , r e s u l t s ) { r e s . j s o n ( r e s u l t s . g e t X m l ) ; } ] } ) ; } ) ;
45. Quality requires structure
46. Structure is a byproduct of convention
47. Express + convention = fun!
48. require("thing") → /node_modules/thing/index.js require("./thing") → /thing.js || /thing/index.js
49. app.js // npm start a p p = ( r e q u i r e ( " . / c o n f i g " ) ) ( ) v a r s e r v e r = r e q u i r e ( ' h t t p ' ) . c r e a t e S e r v e r ( a p p ) s e r v e r . l i s t e n ( a p p . g e t ( ' p o r t ' ) , f u n c t i o n ( ) { c o n s o l e . l o g ( " E x p r e s s r u n n i n g o n " + a p p . g e t ( " p o r t " ) ) } )
50. Routes establish endpoints Controllers are the switchboard Views act as rendering pathways Models contain data and business logic Library functions are tribal knowledge
51. Routes require controllers... Controllers require views... Views require models... Models require library functions... Library functions can exist alone
52. config/index.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( ) { a p p = ( r e q u i r e ( " . . / b o o t s t r a p " ) ) ( ) a p p = ( r e q u i r e ( " . . / l i b " ) ) ( a p p ) a p p = ( r e q u i r e ( " . . / m o d e l s " ) ) ( a p p ) a p p = ( r e q u i r e ( " . . / v i e w s " ) ) ( a p p ) a p p = ( r e q u i r e ( " . . / c o n t r o l l e r s " ) ) ( a p p ) a p p = ( r e q u i r e ( " . . / r o u t e s " ) ) ( a p p ) r e t u r n a p p }
53. Hierarchical dependencies Easy to maintain testability
54. Route through multiple controllers
55. routes/index.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( a p p ) { a p p . a l l ( " / " , a p p . c o n t r o l l e r s . l a n d i n g ) a p p . g e t ( " / c l i e n t / : c l i e n t " , a p p . c o n t r o l l e r s . l a n d i n g ) a p p . p o s t ( " / l o g i n " , a p p . c o n t r o l l e r s . a u t h e n t i c a t e a p p . c o n t r o l l e r s . d i s p l a y ) a p p . g e t ( " / d a s h b o a r d " , a p p . c o n t r o l l e r s . a u t h , a p p . c o n t r o l l e r s . d i s p l a y ) a p p . a l l ( " * " , a p p . c o n t r o l l e r s . 4 0 4 ) }
56. Controllers grok queries, redirect to views (or defer)
57. controllers/index.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( a p p ) { a p p = a p p | | { } a p p . c o n t r o l l e r s = { l a n d i n g : r e q u i r e ( " . / l a n d i n g " ) , d i s p l a y : r e q u i r e ( " . / d i s p l a y " ) , a u t h : r e q u i r e ( " . / a u t h " ) , a u t h e n t i c a t e : r e q u i r e ( " . / a u t h e n t i c a t e " ) } }
58. controllers/landing.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( r e q , r e s , d e f e r , a p p ) { / / H e y , l o o k , i t ' s t h e a p p l i c a t i o n c o n t e x t ! a p p = r e q . a p p | | a p p i f ( r e q . p a r a m ( " c l i e n t " ) ) { r e t u r n a p p . v i e w s . c l i e n t _ s p e c i f i c _ l a n d i n g ( r e q , r e s , a p p ) } a p p . v i e w s . l a n d i n g ( r e q , r e s , a p p ) }
59. controllers/auth.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( r e q , r e s , d e f e r , a p p ) { a p p = r e q . a p p | | a p p i f ( r e q . s e s s i o n . u s e r n a m e ) { r e t u r n d e f e r ( ) } a p p . v i e w s . l o g o u t ( r e q , r e s , a p p ) }
60. Views handle rendering, terminate routes/controllers
61. views/landing.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( r e q , r e s , a p p ) { a p p = a p p | | { } a p p . m o d e l s . u s e r . f i n d O n e ( { u s e r n a m e : r e q . p a r a m ( " u s e r n a m e " ) } ) . e x e c ( f u n c t i o n ( e r r , u s e r ) { i f ( e r r ) { r e s . r e n d e r ( " e r r o r _ t e m p l a t e " ) } i f ( ! u s e r ) { r e s . r e n d e r ( " u s e r _ n o t _ f o u n d " ) } r e s . r e n d e r ( " d a s h b o a r d " , { u s e r n a m e : u s e r . u s e r n a m e } ) } ) }
62. Make code testable without an application context
63. models/index.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( a p p ) { / / C a n ' t s e t p r o p e r t y o f u n d e f i n e d , s o a p p = a p p | | { } a p p . m o d e l s = { u s e r : r e q u i r e ( " . / u s e r " ) , c l i e n t : r e q u i r e ( " . / c l i e n t " ) } r e t u r n a p p }
64. test/models/index.js v a r c o d e = r e q u i r e ( " . . / . . / m o d e l s " ) . m o d e l s i t ( " s h o u l d h a v e a l l t h e m o d e l s w e w a n t " , f u n c t i o n ( ) { a s s e r t . h a s P r o p e r t y ( c o d e . u s e r ) a s s e r t . h a s P r o p e r t y ( c o d e . c l i e n t ) } )
65. Grow the application context
66. lib/index.js v a r l d = r e q u i r e ( " l o d a s h " ) e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( a p p ) { a p p = a p p | | { } a p p . l i b = l d . e x t e n d ( { } , r e q u i r e ( " . / f i b o n a c c i " ) , r e q u i r e ( " . / f u n c t i o n C o m p o s e " ) , r e q u i r e ( " . / b e e r a m i d " ) ) r e t u r n a p p }
67. Break things into component parts for testability
68. lib/beeramid.js v a r b e e r a m i d = f u n c t i o n ( ) { . . . } v a r l e v e l C o u n t e r = f u n c t i o n ( ) { . . . } v a r c a n A m o u n t D e t e r m i n i z e r = f u n c t i o n ( ) { . . . } / / A n y t h i n g n o t e x p o r t e d i s p r i v a t e , u n t e s t a b l e e x p o r t s = m o d u l e . e x p o r t s = { b e e r a m i d : b e e r a m i d , l e v e l C o u n t e r : l e v e l C o u n t e r , c a n A m o u n t D e t e r m i n i z e r : c a n A m o u n t D e t e r m i n i z e r }
69. Test-Driven Development
70. test/lib/beeramid.js v a r c o d e = r e q u i r e ( " . . / . . / l i b / b e e r a m i d " ) i t ( " s h o u l d c a l c u l a t e b e e r a m i d c o r r e c t l y " , f u n c t i o n ( ) { a s s e r t . e q u a l ( c o d e . b e e r a m i d ( 2 , 3 0 ) , 3 ) a s s e r t . e q u a l ( c o d e . b e e r a m i d ( 2 , 2 6 ) , 2 ) } ) i t ( " s h o u l d c a l c u l a t e l e v e l s i z e c o r r e c t l y " , f u n c t i o n ( ) { a s s e r t . e q u a l ( c o d e . l e v e l C o u n t e r ( 2 , 2 ) , 8 ) } )
71. bootstrap.js e x p o r t s = m o d u l e . e x p o r t s = f u n c t i o n ( a p p ) { v a r e x p r e s s = r e q u i r e ( " e x p r e s s " ) v a r a p p = e x p r e s s ( ) a p p . c o n f i g u r e ( f u n c t i o n ( ) { / * a p p . s e t a n d a p p . u s e s t u f f * / } ) / / i n i t i a l i z e c o n n e c t i o n s h e r e t o o r e t u r n a p p } )
72. Testable, logical code = quality
73. Quality + creativity = Fun!
74. PS (of course) we're hiring Kyle Hill kyle@jibe.com @kylehill