Modular JavaScript with Browserify & CommonJS

Why writing front end JavaScript as CommonJS modules and using browserify is awesome.

Transcript

1. Browserify CommonJS + Browserify = Modular Frontend JavaScript Bastian Krol GitHub: Twitter: basti1302 @bastiankrol
2. Why Modules? You start like this... ... adding more and more ... < s c r i p t s r c = " m y _ j a v a s c r i p t _ f i l e . j s " > < / s c r i p t > < s c r i p t s r c = " m o r e _ j a v a s c r i p t . j s " > < / s c r i p t > < s c r i p t s r c = " s p e c i a l _ j a v a s c r i p t _ c o d e . j s " > < / s c r i p t > < s c r i p t s r c = " v e r y _ s p e c i a l _ j a v a s c r i p t _ c o d e . j s " > < / s c r i p t >
3. Why Modules? (2) Pollution of global scope Name clashes and conflicts Implicit dependencies, need to be loaded in correct order
4. Why Modules? (3) Files become large and bloated No separation of concerns Hard to test
5. That is sad :-(
6. CommonJS Modules m a t h . j s e x p o r t s . a d d = f u n c t i o n ( a , b ) { r e t u r n a + b ; } ; e x p o r t s . m u l t i p l y = f u n c t i o n ( a , b ) { r e t u r n a * b ; } ; m a i n - m o d u l e . j s v a r m a t h = r e q u i r e ( ' . / m a t h ' ) ; e x p o r t s . c a l c u l a t e = f u n c t i o n ( x , y , z ) { r e t u r n m a t h . a d d ( m a t h . m u l t i p l y ( x , y ) , m a t h . m u l t i p l y ( y , z ) ) ; } ; Hint: Node.js modules = CommonJS modules
7. Advantages of Modules Global scope is not used Separation of concerns Dependencies are explicit Easy to test
8. That's much better :-)
9. But wait! I can't put that into a script tag, can I?
10. Hello Browserify! $ b r o w s e r i f y m a i n - m o d u l e . j s - - o u t f i l e b u n d l e . j s
11. Using the Bundle < s c r i p t s r c = " b u n d l e . j s " > < / s c r i p t > Loads and executes everything in the browserified bundle.
12. Using the Bundle (2) Nothing in the global scope What about inline JavaScript that needs to call functions in the browserified bundle?
13. Browserify & UMD $ b r o w s e r i f y m a i n - m o d u l e . j s - - o u t f i l e b u n d l e . j s - - s t a n d a l o n e m a i n m o d u l e Actually, - - s t a n d a l o n e puts a Universal Module Definition into the bundle ... and can then be used with an AMD loader (RequireJS) ... or falls back to exporting a global variable < s c r i p t s r c = " b u n d l e . j s " > < / s c r i p t > < s c r i p t > < / s c r i p t > m a i n m o d u l e . c a l c u l a t e ( 4 2 , 1 3 , 2 ) ;
14. Multiple Bundles You can require modules from another script tag Build bundle A with - - r e q u i r e m o d u l e –> exports m o d u l e Build bundle B with - - e x t e r n a l m o d u l e –> uses m o d u l e from bundle A
15. Browserify & npm Use packages from npm Require them in your modules Browserify will browserify your stuff and your dependencies Publish your own (browserifiable) packages an npm!
16. Browserify & Node.js Use Node.js core API: events stream url path querystring http crypto ... Browserify has shims for those
17. Transforms uglify/minify bundled modules (uglifyify) compile coffee script (coffeeify) inline file contents (brfs) convert AMD modules to CommonJS modules (deAMDify) include bower components in your bundle (debowerify) include component.js components in your bundle (decomponentify) ... many, many more
18. Cross Platform JavaScript 1. Writing a library that works in Node.js and in the browser? 2. Build it with browserify! 3. Let browserify generate a UMD 4. Publish to npm 5. Others can use it via npm/browserify, AMD or script tag 6. The world has just become a better place
19. Browserify – Pain Points Build step is required Watch out for file size (Node core & npm) Browserify adds some boilerplate code Frameworks that have a built-in module system (like AngularJS) + CommonJS modules –> might be confusing
20. Useful Tools Watchify – rebuild bundle when files change - quite fast Grunt or Gulp with browserify/watchify plug-ins
21. Alternatives AMD (RequireJS) battle tested for frontend projects no build step required clunky syntax no npm (though there is bower) EcmaScript 6 Modules with transpiler will become standard currently: build step required in future: directly supported by browsers
22. Thx! Questions? Bastian Krol / @bastiankrol