Components Now!

WebComponents is a great idea! The problem is that WebComponents API is in working draft...

Why we don't use just Components? Why we are waiting for that Web- prefix? We can use them right now and without havy polyfills! He will show you how to write Components today!

Video https://www.youtube.com/watch?v=cROv1myc6NM

Transcript

2. About myself •Front-End Engineer at Yandex •Developer of Yandex.Taxi and Yandex.Mobile •JavaScript Teacher •Blogger 02
4. Components Now! Mikhail Davydov MetaRefresh, 15 Feb 2014
5. Code libraries
6. Code libraries •jQuery — fixes DOM •Underscore — fills ECMAScript 3-5 gap •Backbone — brings MV* •They are created to fix Web For some historical reasons many good tools are libraries. The DOM is a Mess 2009 06
7. Libraries are everywhere
8. Libraries are big •Heavy –jQuery 2.0.3 — 230K (unpacked) •Hard to understand –Cyclomatic complexity of $.ajax — 43 •Too powerful –$.ajax, $.animate, _ 08
9. Libraries are tightly coupled •Hard to get a small part –$.Deferred, $.ajax –_.template •Manual extraction •Their modules don't help much 09
10. Dependencies management •Dependency on jQuery •Libraries require libraries –Backbone+jQuery+Underscore •Manual dependencies management –Bower and Npm are lifesavers 10
11. Web is fixed*
13. Critical DOM APIs •querySelector •CSS3 Selectors* •Web Storage (localStorage) •Cross-Origin Resource Sharing* * fully with polyfills Can I Use 13
14. ECMAScript 5
15. Polyfills can fix the rest •CSS3 Selectors (slow, not recommended) •Cross-Origin Resource Sharing •HTML5 Elements •ECMAScript 5 HTML5 Please polyfills 15
16. Mobile
17. Mobile Growth
18. Why do we use libraries?
19. Components
20. Simple
21. Components are simple •Lightweight –dom — 28K, 3K self (unpacked) •Single responsibility & KISS Principle •Easy to understand –Maintain –Write tests 21
22. Standalone
23. Components are standalone •Contain all dependencies –Most of them are external •Easy to reuse – bower i name – npm i name •It is simple to use a part 23
24. Isolated
25. Components are isolated •Do not interfere with others –Scoped CSS –Flexible layout –No globals leak •Have restricted access to others – require() 25
27. WebComponents •Idea of Custom HTML Elements •API/Framework –Shadow DOM (Encapsulation) –HTML Imports & Templates –Template Binding Web components and the future of web development from MR 2013 27
28. WebComponents in 2014 HTML Templates Shadow DOM Custom Elements HTML Imports It is possible to polyfill others using Polymer. 28
29. Alternatives for these APIs WebComponents API Alternative Custom Elements Component engines Shadow DOM BEM Methodology HTML Templates Template engines HTML Imports Build tools Scoped CSS BEM or OOCSS Template Binding Data binding 29
30. Component engines •X-Tag •jQuery UI Widgets •Dojo Widgets •React •bem-tools 30
32. BEM briefly •Avoid CSS cascade •Block — Custom Element •Element — Shadow DOM •Modifier — Component State Maintainable frontend development with BEM from MR 2013 32
33. .tab-panel — Block .tab-panel__tab — Element .tab-panel__tab_state_active
34. Let's build the Component!
36. Keep in mind that •Component is Simple –KISS •Component is Standalone –Dependencies •Component is Isolated –Layout, CSS, JS 36
37. Package file
38. Package file is the contract // bower.json { "name" "name": "my-share" "my-share", "version" "version": "1.0.0" "1.0.0", "main" "main": ["my-share.js" "my-share.js"] } Bower and format of bower.json 01. 02. 03. 04. 05. 06. 38
39. HTML Layout
40. Private HTML Layout <!-- my-share.html --> <a a href href=" "{{ href }} {{ href }}" " class class="my-share" "my-share"> <img img src src=" "{{ icon }} {{ icon }}" " class class="my-share__icon" "my-share__icon"/> <span span class class="my-share__label" "my-share__label">{{ label }}</span span> </a a> This template is written using BEM Methodology. 01. 02. 03. 04. 05. 40
41. Interface
42. Interface <a a class class="my-share" "my-share" data-href="{{ href }}" data-icon="{{ icon }}" >{{ label }}</a a> This interface is similar to the WebComponents. 01. 02. 03. 04. 42
43. WebComponents for comparison <my-share my-share href="{{ href }}" icon="{{ icon }}" >{{ label }}</my-share my-share> 01. 02. 03. 04. 43
44. CSS of Component . .my-share my-share {} .my my-share__icon { vertical-align vertical-align: middle; middle; height height: 16px; 16px; } .my my-share__label { padding-left padding-left: 5px; 5px; } 01. 02. 03. 04. 05. 06. 07. 08. 44
45. CSS of WebComponent my-share {} .icon { vertical-align vertical-align: middle; middle; height height: 16px; 16px; } .label { padding-left padding-left: 5px; 5px; } 01. 02. 03. 04. 05. 06. 07. 08. 45
46. CSS is isolated •WebComponent — DOM API – <style scoped> •BEM –Avoid CSS cascade –Naming conventions .block__element 46
47. Dependencies
48. External dependencies // bower.json "dependencies" "dependencies": { "tpl" "tpl": "azproduction/lodash-template" "azproduction/lodash-template", "domify" "domify": "component/domify" "component/domify", "decl" "decl": "azproduction/decl" "azproduction/decl" } Declare all external dependencies. 01. 02. 03. 04. 05. 06. 48
49. Component relations // my-share.js var var tpl = require('tpl' 'tpl'), decl = require('decl' 'decl'), domify = require('domify' 'domify'); var var html = require('templates/my-share' 'templates/my-share'), template = tpl(html); 01. 02. 03. 04. 05. 06. 07. 49
50. Component logic function function MyShare(el) { this this.options = this this.collectOptions(el); this this.el = this this.render(); this this.delegateEvents(); this this.replaceElement(el); } decl('.my-share' '.my-share', MyShare); module.exports = MyShare; 01. 02. 03. 04. 05. 06. 07. 08. 50
51. JavaScript is isolated •CommonJS/Modules –No globals leak –It asks for requirements –It provides resources •AMD can be used too 51
52. Assemble
53. Assemble component •Resolve all requirements •Compile –styles, scripts, templates •Assemble scripts and templates •Concatenate styles 53
54. Component build tools •bem-tools •Component •Browserify •LMD 54
55. Using my-share Component <a a class class="my-share" "my-share" ... ...>Tweet</a a> <link link rel rel="stylesheet" "stylesheet" href href=" "my-share.css my-share.css" "/> <script script src src=" "my-share.js my-share.js" "></script script> Compare with WebComponents. 01. 02. 03. 55
56. Using my-share WebComponent <my-share my-share ... ...>Tweet</my-share my-share> <link link rel rel="import" "import" href href=" "my-share.html my-share.html" "/> 01. 02. 56
57. Tweet Live example 57
60. Conclusion •Web is Fixed, Mobile is Growing •Libraries are big and clumsy •WebComponents == API •Write and use Components 60
61. Components Now! Mikhail Davydov @azproduction 61
62. Useful resources •Code of my-share •You might not need jQuery •BEM Methodology •Web Components •Polymer Project 62
63. clck.ru/94Tqf
64. Sources of images • minecraft.gamepedia.com/Blocks • fr.fotopedia.com/wiki/Bibliothèque#!/items/flickr-6899137527 • www.planetminecraft.com/project/minecraft-site/ • investments.academic.ru/1513/Форвардный_контракт • frozen-lama.deviantart.com/art/Minecraft-Compound-Door-209872466 • www.postandcourier.com/article/20120620/pc1002/120629985 • isintu.com/features/responsive-design/ • nicolaijuhler.wordpress.com/ • r3c0nic.deviantart.com/art/minecraft-Blueprint-293455933 • ru-wallp.com/view/1542/ 64