Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Learning to Fly — Twitter Flight and Mixins
Search
Angus Croll
August 23, 2013
Technology
23
4.6k
Learning to Fly — Twitter Flight and Mixins
Presented at BrazilJS, Porto Alegre, August 22nd 2013
Angus Croll
August 23, 2013
Tweet
Share
More Decks by Angus Croll
See All by Angus Croll
The Book Nerd's Guide to JavaScript
anguscroll
14
4.3k
Stop being Perfect
anguscroll
11
1.6k
ES6 Uncensored
anguscroll
72
12k
JavaScript is Literature is JavaScript
anguscroll
21
3.4k
The Politics of JavaScript
anguscroll
122
23k
Parlez-Vous JavaScript
anguscroll
33
6.4k
Break all the Rulez
anguscroll
42
16k
How we Learned to Stop Worrying and Love JavaScript
anguscroll
90
22k
Other Decks in Technology
See All in Technology
アウトプットから始めるOSSコントリビューション 〜eslint-plugin-vueの場合〜 #vuefes
bengo4com
3
1.8k
【SORACOM UG Explorer 2025】さらなる10年へ ~ SORACOM MVC 発表
soracom
PRO
0
160
AIの個性を理解し、指揮する
shoota
1
130
20251027_マルチエージェントとは
almondo_event
1
450
AI AgentをLangflowでサクッと作って、1日働かせてみた!
yano13
1
160
.NET 10のBlazorの期待の新機能
htkym
0
110
OSSで50の競合と戦うためにやったこと
yamadashy
3
1k
「タコピーの原罪」から学ぶ間違った”支援” / the bad support of Takopii
piyonakajima
0
150
20251027_findyさん_音声エージェントLT
almondo_event
2
460
IoTLT@ストラタシスジャパン_20251021
norioikedo
0
140
AIプロダクトのプロンプト実践テクニック / Practical Techniques for AI Product Prompts
saka2jp
0
110
クラウドとリアルの融合により、製造業はどう変わるのか?〜クラスメソッドの製造業への取組と共に〜
hamadakoji
0
440
Featured
See All Featured
Designing for Performance
lara
610
69k
Gamification - CAS2011
davidbonilla
81
5.5k
The Cost Of JavaScript in 2023
addyosmani
55
9.1k
Design and Strategy: How to Deal with People Who Don’t "Get" Design
morganepeng
132
19k
The Art of Delivering Value - GDevCon NA Keynote
reverentgeek
16
1.7k
Visualization
eitanlees
149
16k
jQuery: Nuts, Bolts and Bling
dougneiner
65
7.9k
The MySQL Ecosystem @ GitHub 2015
samlambert
251
13k
Balancing Empowerment & Direction
lara
5
700
ピンチをチャンスに:未来をつくるプロダクトロードマップ #pmconf2020
aki_iinuma
127
54k
Docker and Python
trallard
46
3.6k
Intergalactic Javascript Robots from Outer Space
tanoku
272
27k
Transcript
Learning to fly Twitter Flight and Mixins @angustweets Thursday, August
22, 13
the most difficult part of JS inheritance... And on the
6th day, God created an abundance of Talking Animals, that they may be used in JavaScript inheritance examples. Thursday, August 22, 13
So, talking animals it is! meow!! Thursday, August 22, 13
Flight flightjs.github.io An event driven web framework by Twitter Thursday,
August 22, 13
Flight powers... twitter.com tweetdeck gumroad yinzcam crashalytics and more... Thursday,
August 22, 13
A set of components which bind functionality to DOM Nodes...
Thursday, August 22, 13
github.com/flightjs/example-app Thursday, August 22, 13
github.com/flightjs/example-app Thursday, August 22, 13
Components are completely decoupled and communicate via event bubbling Thursday,
August 22, 13
Thursday, August 22, 13
Components often share behaviours Thursday, August 22, 13
Components often share behaviours So we needed a re-use technique
Thursday, August 22, 13
Inheritance classical composition mixins Functions Object.create Constructor.prototype function passing /
callbacks Objects call/apply functional mixins (Some) JavaScript Re-use Patterns Thursday, August 22, 13
Inheritance classical composition mixins Functions Object.create Constructor.prototype function passing /
callbacks Objects call/apply functional mixins (Some) JavaScript Re-use Patterns Thursday, August 22, 13
Classical Inheritance Thursday, August 22, 13
ES 6 is giving us class. Some libraries have their
own versions. Thursday, August 22, 13
implementation varies widely and abstraction is often leaky (const, static)
class, extend and super are reserved words in particular, the relationship between this and super is difficult... Thursday, August 22, 13
//Prototype.js var SwimmingAnimal = Class.create(Animal, { type: 'SwimmingAnimal', speak: function($super)
{ return $super() + ", glug"; } }); //https://github.com/ded/klass var Alien = SuperHuman.extend({ speak: function() { this.supr(); //speak like a SuperHuman } }); Thursday, August 22, 13
Do you even want classes? Thursday, August 22, 13
Animal Walking Animal Swimming Animal Flying Animal Cat Elephant Crocodile
Whale Eagle Bat Egg-laying Animal Migrating Animal Thursday, August 22, 13
Crocodile Animal Walking Animal Swimming Animal Flying Animal Cat Elephant
Whale Eagle Bat Egg-laying Animal Migrating Animal Thursday, August 22, 13
Crocodile Animal Walking Animal Swimming Animal Flying Animal Cat Elephant
Whale Eagle Bat Egg-laying Animal Migrating Animal WTF? I walk too!! Thursday, August 22, 13
Animal Walking Animal Swimming Animal Flying Animal Cat Elephant Crocodile
Whale Eagle Bat Egg-laying Animal Migrating Animal Thursday, August 22, 13
Duck? Animal Walking Animal Swimming Animal Flying Animal Cat Elephant
Crocodile Whale Eagle Bat Egg-laying Animal Migrating Animal Thursday, August 22, 13
Duck? Animal Cat Elephant Crocodile Whale Eagle Bat Thursday, August
22, 13
Duck? Animal Cat Elephant Crocodile Whale Eagle Bat Walking Animal
Swimming Animal Flying Animal Egg-laying Animal Migrating Animal Thursday, August 22, 13
Classical inheritance Requires up-front knowledge of general case Single rooted
hierarchy We’re really bad at classification Thursday, August 22, 13
Constructor.prototype chaining Thursday, August 22, 13
awkward and unnatural Thursday, August 22, 13
var Animal = function(gender, says) { this.gender = gender; this.says
= says; }; var WalkingAnimal = function(gender, says) { Animal.call(this, gender, says); } WalkingAnimal.prototype = new Animal(); Thursday, August 22, 13
...and new Constructor syntax is classical inheritance Thursday, August 22,
13
Beyond classification... Thursday, August 22, 13
19th century British philosophers Whewell and Jevons argued that there
are no objectively “right” classifications Thursday, August 22, 13
“In general, when working with prototypes, one typically chooses not
to categorize but to exploit alikeness.” –Antero Taivalsaari (Nokia Research Center) Thursday, August 22, 13
liberates prototype chaining from classification Object.create Thursday, August 22, 13
var animalProto = { speak: function() { console.log(this.says); } }
var walkingAnimalProto = Object.create(animalProto); // then augment walkingAnimalProto here... Thursday, August 22, 13
but, that second argument :’’( Thursday, August 22, 13
var animalProto = { speak: function() { console.log(this.says); } }
var walkingAnimalProto = Object.create( animalProto, { walk: { value: function() { console.log('walking'); } } //... } ); Thursday, August 22, 13
and inheritance is still single rooted Thursday, August 22, 13
The sad thing is that we even care about inheritance
hierarchies... Thursday, August 22, 13
The sad thing is that we even care about inheritance
hierarchies... ...because in JavaScript they’re quite unnecessary... Thursday, August 22, 13
JavaScript has first class functions Any function can be assigned
to any object Thursday, August 22, 13
Mixins Thursday, August 22, 13
//A property copy mixin var withWalking = { walk: function()
{ console.log('walking'); }, turn: function(direction) { console.log('turning', direction); }, stopWalking: function() { console.log('stopped walking'); } }; Thursday, August 22, 13
var extend = function(destination, source) { for (var k in
source) { if (source.hasOwnProperty(k)) { destination[k] = source[k]; } } return destination; }; extend(Crocodile.prototype, withWalking); extend(Crocodile.prototype, withSwimming); Thursday, August 22, 13
No hierarchical constraints Functionality is grouped by what it does
not who it belongs to Define special cases first; common code later Thursday, August 22, 13
Mixin must know about target Properties can only clobber But...
Thursday, August 22, 13
Functional Mixins Thursday, August 22, 13
var withWalking = function() { this.walk = function() { console.log('walking');
}; this.turn = function(direction) { console.log('turning', direction); }; this.stopWalking = function() { console.log('stopped walking'); }; }; Thursday, August 22, 13
function Crocodile(name, gender) { this.name = name; this.gender = gender;
} Crocodile.prototype.stalkTourists = function() { //.. }; withWalking.call(Crocodile.prototype); withSwimming.call(Crocodile.prototype); Thursday, August 22, 13
Flight uses functional mixins Thursday, August 22, 13
github.com/flightjs/example-app Thursday, August 22, 13
function withSelect() { this.defaultAttrs({ selectedIds: [] }); this.selectItem = function($item,
append) { $item.addClass(this.attr.selectedClass); this.attr.selectedIds.push($item.attr('id')); this.trigger('uiSelectionChanged', {selIds: this.attr.selectedIds}); }; this.unselectItem = function($item) { $item.removeClass(this.attr.selectedClass); this.attr.selectedIds.splice(getIdIndex($item), 1); this.trigger('uiSelectionChanged', {selIds: this.attr.selectedIds}); }; } Thursday, August 22, 13
defineComponent(mailItems, withSelect); defineComponent(folders, withSelect); defineComponent(moveToSelector, withSelect); Thursday, August 22, 13
The Advice Mixin Thursday, August 22, 13
advice.js is a mixin Thursday, August 22, 13
advice.js is a mixin it lets you add custom code
before(), after() or around() an existing function. Thursday, August 22, 13
all flight mixins get advice.js for free Thursday, August 22,
13
all flight mixins get advice.js for free so mixins can
augment functions, not clobber them Thursday, August 22, 13
withAdvice.call(Crocodile.prototype); function withFlu() { this.before('walk', function() { console.log('sniff'); }); }
var sickCrocodile = new Crocodile(); withFlu.call(sickCrocodile); sickCrocodile.walk(); //"sniff, pad, pad, pad, pad" Thursday, August 22, 13
function withSelect() { this.defaultAttrs({ selectedIds: [] }); this.toggleItemSelect = function(ev,
data) { var $item = $(data.el), append; if ($item.hasClass(this.attr.selectedClass)) { this.unselectItem($item); } else { this.selectItem($item, isMultiSelect(ev)); } }; this.selectItem = function($item, append) {/*..*/}; this.unselectItem = function($item) {/*..*/}; this.after('initialize', function() { this.on(this.select('itemSelector'), 'click', this.toggleItemSelect); }); } Thursday, August 22, 13
So why do we like functional mixins? Thursday, August 22,
13
Mixins as verbs instead of nouns. Mixins are functions. We
can take advantage of closure scope and arguments. A mixin can be applied to any object type: prototype, instance, whatever. Advice allows functional mixins to augment existing functions, not clobber them. Thursday, August 22, 13
Works with the language Simple to understand No surprises! Thursday,
August 22, 13
Obrigado! @angustweets javascriptweblog.wordpress.com/2011/05/31/a-fresh-look-at- javascript-mixins/ Thursday, August 22, 13