Rails-like JavaScript Using CoffeeScript, Backbone.js and Jasmine

Rails-like JavaScript using CoffeeScript, Backbone.js and Jasmine

Raimonds Simanovskis

Raimonds Simanovskis

github.com/rsim

@rsim

.com

The Problem

Ruby code in Rails

JavaScript code in Rails 3.0.x

application.js// Place your application-specific JavaScript functions and classes here// This file is automatically included by javascript_include_tag :defaults

Which leads to...(example from Redmine)

application.js(example from Redmine)

/* redMine - project management software Copyright (C) 2006-2008 Jean-Philippe Lang */

function checkAll (id, checked) { var els = Element.descendants(id); for (var i = 0; i < els.length; i++) { if (els[i].disabled==false) { els[i].checked = checked; } }}

function toggleCheckboxesBySelector(selector) { boxes = $$(selector); var all_checked = true; for (i = 0; i < boxes.length; i++) { if (boxes[i].checked == false) { all_checked = false; } } for (i = 0; i < boxes.length; i++) { boxes[i].checked = !all_checked; }}

function setCheckboxesBySelector(checked, selector) { var boxes = $$(selector); boxes.each(function(ele) { ele.checked = checked; });}

function showAndScrollTo(id, focus) { Element.show(id); if (focus!=null) { Form.Element.focus(focus); } Element.scrollTo(id);}

function toggleRowGroup(el) { var tr = Element.up(el, 'tr'); var n = Element.next(tr); tr.toggleClassName('open'); while (n != undefined && !n.hasClassName('group')) { Element.toggle(n); n = Element.next(n); }}

function collapseAllRowGroups(el) { var tbody = Element.up(el, 'tbody'); tbody.childElements('tr').each(function(tr) { if (tr.hasClassName('group')) { tr.removeClassName('open'); } else { tr.hide(); } })}

function expandAllRowGroups(el) { var tbody = Element.up(el, 'tbody'); tbody.childElements('tr').each(function(tr) { if (tr.hasClassName('group')) { tr.addClassName('open'); } else { tr.show(); } })}

function toggleAllRowGroups(el) { var tr = Element.up(el, 'tr'); if (tr.hasClassName('open')) { collapseAllRowGroups(el); } else { expandAllRowGroups(el); }}

function toggleFieldset(el) { var fieldset = Element.up(el, 'fieldset'); fieldset.toggleClassName('collapsed'); Effect.toggle(fieldset.down('div'), 'slide', {duration:0.2});}

function hideFieldset(el) { var fieldset = Element.up(el, 'fieldset'); fieldset.toggleClassName('collapsed'); fieldset.down('div').hide();}

var fileFieldCount = 1;

function addFileField() { if (fileFieldCount >= 10) return false fileFieldCount++; var f = document.createElement("input"); f.type = "file"; f.name = "attachments[" + fileFieldCount + "][file]"; f.size = 30; var d = document.createElement("input"); d.type = "text"; d.name = "attachments[" + fileFieldCount + "][description]"; d.size = 60; var dLabel = new Element('label'); dLabel.addClassName('inline'); // Pulls the languge value used for Optional Description dLabel.update($('attachment_description_label_content').innerHTML) p = document.getElementById("attachments_fields"); p.appendChild(document.createElement("br")); p.appendChild(f); p.appendChild(dLabel); dLabel.appendChild(d);

}

function showTab(name) { var f = $$('div#content .tab-content'); for(var i=0; i<f.length; i++){ Element.hide(f[i]); } var f = $$('div.tabs a'); for(var i=0; i<f.length; i++){ Element.removeClassName(f[i], "selected"); } Element.show('tab-content-' + name); Element.addClassName('tab-' + name, "selected"); return false;}

function moveTabRight(el) { var lis = Element.up(el, 'div.tabs').down('ul').childElements(); var tabsWidth = 0; var i; for (i=0; i<lis.length; i++) { if (lis[i].visible()) { tabsWidth += lis[i].getWidth() + 6; } } if (tabsWidth < Element.up(el, 'div.tabs').getWidth() - 60) { return; } i=0; while (i<lis.length && !lis[i].visible()) { i++; } lis[i].hide();}

function moveTabLeft(el) { var lis = Element.up(el, 'div.tabs').down('ul').childElements(); var i = 0; while (i<lis.length && !lis[i].visible()) { i++; } if (i>0) { lis[i-1].show(); }}

function displayTabsButtons() { var lis; var tabsWidth = 0; var i; $$('div.tabs').each(function(el) { lis = el.down('ul').childElements(); for (i=0; i<lis.length; i++) { if (lis[i].visible()) { tabsWidth += lis[i].getWidth() + 6; } } if ((tabsWidth < el.getWidth() - 60) && (lis[0].visible())) { el.down('div.tabs-buttons').hide(); } else { el.down('div.tabs-buttons').show(); } });}

function setPredecessorFieldsVisibility() { relationType = $('relation_relation_type'); if (relationType && (relationType.value == "precedes" || relationType.value == "follows")) { Element.show('predecessor_fields'); } else { Element.hide('predecessor_fields'); }}

function promptToRemote(text, param, url) { value = prompt(text + ':'); if (value) { new Ajax.Request(url + '?' + param + '=' + encodeURIComponent(value), {asynchronous:true, evalScripts:true}); return false; }}

function collapseScmEntry(id) { var els = document.getElementsByClassName(id, 'browser'); for (var i = 0; i < els.length; i++) { if (els[i].hasClassName('open')) { collapseScmEntry(els[i].id); } Element.hide(els[i]); } $(id).removeClassName('open');}

function expandScmEntry(id) { var els = document.getElementsByClassName(id, 'browser'); for (var i = 0; i < els.length; i++) { Element.show(els[i]); if (els[i].hasClassName('loaded') && !els[i].hasClassName('collapsed')) { expandScmEntry(els[i].id); } } $(id).addClassName('open');}

function scmEntryClick(id) { el = $(id); if (el.hasClassName('open')) { collapseScmEntry(id); el.addClassName('collapsed'); return false; } else if (el.hasClassName('loaded')) { expandScmEntry(id); el.removeClassName('collapsed'); return false; } if (el.hasClassName('loading')) { return false; } el.addClassName('loading'); return true;}

function scmEntryLoaded(id) { Element.addClassName(id, 'open'); Element.addClassName(id, 'loaded'); Element.removeClassName(id, 'loading');}

function randomKey(size) { var chars = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'); var key = ''; for (i = 0; i < size; i++) { key += chars[Math.floor(Math.random() * chars.length)]; } return key;}

function observeParentIssueField(url) { new Ajax.Autocompleter('issue_parent_issue_id', 'parent_issue_candidates', url, { minChars: 3, frequency: 0.5, paramName: 'q', updateElement: function(value) { document.getElementById('issue_parent_issue_id').value = value.id; }});}

function observeRelatedIssueField(url) { new Ajax.Autocompleter('relation_issue_to_id', 'related_issue_candidates', url, { minChars: 3, frequency: 0.5, paramName: 'q', updateElement: function(value) { document.getElementById('relation_issue_to_id').value = value.id; }, parameters: 'scope=all' });}

function setVisible(id, visible) { var el = $(id); if (el) {if (visible) {el.show();} else {el.hide();}}}

function observeProjectModules() { var f = function() { /* Hides trackers and issues custom fields on the new project form when issue_tracking module is disabled */ var c = ($('project_enabled_module_names_issue_tracking').checked == true); setVisible('project_trackers', c); setVisible('project_issue_custom_fields', c); }; Event.observe(window, 'load', f); Event.observe('project_enabled_module_names_issue_tracking', 'change', f);}

/* * Class used to warn user when leaving a page with unsaved textarea * Author: [email protected]*/

var WarnLeavingUnsaved = Class.create({ observedForms: false, observedElements: false, changedForms: false, message: null, initialize: function(message){ this.observedForms = $$('form'); this.observedElements = $$('textarea'); this.message = message; this.observedElements.each(this.observeChange.bind(this)); this.observedForms.each(this.submitAction.bind(this)); window.onbeforeunload = this.unload.bind(this); }, unload: function(){ if(this.changedForms) return this.message; }, setChanged: function(){ this.changedForms = true; }, setUnchanged: function(){ this.changedForms = false; }, observeChange: function(element){ element.observe('change',this.setChanged.bindAsEventListener(this)); }, submitAction: function(element){ element.observe('submit',this.setUnchanged.bindAsEventListener(this)); }});

/* * 1 - registers a callback which copies the csrf token into the * X-CSRF-Token header with each ajax request. Necessary to * work with rails applications which have fixed * CVE-2011-0447 * 2 - shows and hides ajax indicator */Ajax.Responders.register({ onCreate: function(request){ var csrf_meta_tag = $$('meta[name=csrf-token]')[0];

if (csrf_meta_tag) { var header = 'X-CSRF-Token', token = csrf_meta_tag.readAttribute('content');

if (!request.options.requestHeaders) { request.options.requestHeaders = {}; } request.options.requestHeaders[header] = token; }

if ($('ajax-indicator') && Ajax.activeRequestCount > 0) { Element.show('ajax-indicator'); } }, onComplete: function(){ if ($('ajax-indicator') && Ajax.activeRequestCount == 0) { Element.hide('ajax-indicator'); } }});

function hideOnLoad() { $$('.hol').each(function(el) { el.hide(); });}

Event.observe(window, 'load', hideOnLoad);

application.js(example from Redmine)

/* redMine - project management software Copyright (C) 2006-2008 Jean-Philippe Lang */

function checkAll (id, checked) { var els = Element.descendants(id); for (var i = 0; i < els.length; i++) { if (els[i].disabled==false) { els[i].checked = checked; } }}

function toggleCheckboxesBySelector(selector) { boxes = $$(selector); var all_checked = true; for (i = 0; i < boxes.length; i++) { if (boxes[i].checked == false) { all_checked = false; } } for (i = 0; i < boxes.length; i++) { boxes[i].checked = !all_checked; }}

function setCheckboxesBySelector(checked, selector) { var boxes = $$(selector); boxes.each(function(ele) { ele.checked = checked; });}

function showAndScrollTo(id, focus) { Element.show(id); if (focus!=null) { Form.Element.focus(focus); } Element.scrollTo(id);}

function toggleRowGroup(el) { var tr = Element.up(el, 'tr'); var n = Element.next(tr); tr.toggleClassName('open'); while (n != undefined && !n.hasClassName('group')) { Element.toggle(n); n = Element.next(n); }}

function collapseAllRowGroups(el) { var tbody = Element.up(el, 'tbody'); tbody.childElements('tr').each(function(tr) { if (tr.hasClassName('group')) { tr.removeClassName('open'); } else { tr.hide(); } })}

function expandAllRowGroups(el) { var tbody = Element.up(el, 'tbody'); tbody.childElements('tr').each(function(tr) { if (tr.hasClassName('group')) { tr.addClassName('open'); } else { tr.show(); } })}

function toggleAllRowGroups(el) { var tr = Element.up(el, 'tr'); if (tr.hasClassName('open')) { collapseAllRowGroups(el); } else { expandAllRowGroups(el); }}

function toggleFieldset(el) { var fieldset = Element.up(el, 'fieldset'); fieldset.toggleClassName('collapsed'); Effect.toggle(fieldset.down('div'), 'slide', {duration:0.2});}

function hideFieldset(el) { var fieldset = Element.up(el, 'fieldset'); fieldset.toggleClassName('collapsed'); fieldset.down('div').hide();}

var fileFieldCount = 1;

function addFileField() { if (fileFieldCount >= 10) return false fileFieldCount++; var f = document.createElement("input"); f.type = "file"; f.name = "attachments[" + fileFieldCount + "][file]"; f.size = 30; var d = document.createElement("input"); d.type = "text"; d.name = "attachments[" + fileFieldCount + "][description]"; d.size = 60; var dLabel = new Element('label'); dLabel.addClassName('inline'); // Pulls the languge value used for Optional Description dLabel.update($('attachment_description_label_content').innerHTML) p = document.getElementById("attachments_fields"); p.appendChild(document.createElement("br")); p.appendChild(f); p.appendChild(dLabel); dLabel.appendChild(d);

}

function showTab(name) { var f = $$('div#content .tab-content'); for(var i=0; i<f.length; i++){ Element.hide(f[i]); } var f = $$('div.tabs a'); for(var i=0; i<f.length; i++){ Element.removeClassName(f[i], "selected"); } Element.show('tab-content-' + name); Element.addClassName('tab-' + name, "selected"); return false;}

function moveTabRight(el) { var lis = Element.up(el, 'div.tabs').down('ul').childElements(); var tabsWidth = 0; var i; for (i=0; i<lis.length; i++) { if (lis[i].visible()) { tabsWidth += lis[i].getWidth() + 6; } } if (tabsWidth < Element.up(el, 'div.tabs').getWidth() - 60) { return; } i=0; while (i<lis.length && !lis[i].visible()) { i++; } lis[i].hide();}

function moveTabLeft(el) { var lis = Element.up(el, 'div.tabs').down('ul').childElements(); var i = 0; while (i<lis.length && !lis[i].visible()) { i++; } if (i>0) { lis[i-1].show(); }}

function displayTabsButtons() { var lis; var tabsWidth = 0; var i; $$('div.tabs').each(function(el) { lis = el.down('ul').childElements(); for (i=0; i<lis.length; i++) { if (lis[i].visible()) { tabsWidth += lis[i].getWidth() + 6; } } if ((tabsWidth < el.getWidth() - 60) && (lis[0].visible())) { el.down('div.tabs-buttons').hide(); } else { el.down('div.tabs-buttons').show(); } });}

function setPredecessorFieldsVisibility() { relationType = $('relation_relation_type'); if (relationType && (relationType.value == "precedes" || relationType.value == "follows")) { Element.show('predecessor_fields'); } else { Element.hide('predecessor_fields'); }}

function promptToRemote(text, param, url) { value = prompt(text + ':'); if (value) { new Ajax.Request(url + '?' + param + '=' + encodeURIComponent(value), {asynchronous:true, evalScripts:true}); return false; }}

function collapseScmEntry(id) { var els = document.getElementsByClassName(id, 'browser'); for (var i = 0; i < els.length; i++) { if (els[i].hasClassName('open')) { collapseScmEntry(els[i].id); } Element.hide(els[i]); } $(id).removeClassName('open');}

function expandScmEntry(id) { var els = document.getElementsByClassName(id, 'browser'); for (var i = 0; i < els.length; i++) { Element.show(els[i]); if (els[i].hasClassName('loaded') && !els[i].hasClassName('collapsed')) { expandScmEntry(els[i].id); } } $(id).addClassName('open');}

function scmEntryClick(id) { el = $(id); if (el.hasClassName('open')) { collapseScmEntry(id); el.addClassName('collapsed'); return false; } else if (el.hasClassName('loaded')) { expandScmEntry(id); el.removeClassName('collapsed'); return false; } if (el.hasClassName('loading')) { return false; } el.addClassName('loading'); return true;}

function scmEntryLoaded(id) { Element.addClassName(id, 'open'); Element.addClassName(id, 'loaded'); Element.removeClassName(id, 'loading');}

function randomKey(size) { var chars = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'); var key = ''; for (i = 0; i < size; i++) { key += chars[Math.floor(Math.random() * chars.length)]; } return key;}

function observeParentIssueField(url) { new Ajax.Autocompleter('issue_parent_issue_id', 'parent_issue_candidates', url, { minChars: 3, frequency: 0.5, paramName: 'q', updateElement: function(value) { document.getElementById('issue_parent_issue_id').value = value.id; }});}

function observeRelatedIssueField(url) { new Ajax.Autocompleter('relation_issue_to_id', 'related_issue_candidates', url, { minChars: 3, frequency: 0.5, paramName: 'q', updateElement: function(value) { document.getElementById('relation_issue_to_id').value = value.id; }, parameters: 'scope=all' });}

function setVisible(id, visible) { var el = $(id); if (el) {if (visible) {el.show();} else {el.hide();}}}

function observeProjectModules() { var f = function() { /* Hides trackers and issues custom fields on the new project form when issue_tracking module is disabled */ var c = ($('project_enabled_module_names_issue_tracking').checked == true); setVisible('project_trackers', c); setVisible('project_issue_custom_fields', c); }; Event.observe(window, 'load', f); Event.observe('project_enabled_module_names_issue_tracking', 'change', f);}

/* * Class used to warn user when leaving a page with unsaved textarea * Author: [email protected]*/

var WarnLeavingUnsaved = Class.create({ observedForms: false, observedElements: false, changedForms: false, message: null, initialize: function(message){ this.observedForms = $$('form'); this.observedElements = $$('textarea'); this.message = message; this.observedElements.each(this.observeChange.bind(this)); this.observedForms.each(this.submitAction.bind(this)); window.onbeforeunload = this.unload.bind(this); }, unload: function(){ if(this.changedForms) return this.message; }, setChanged: function(){ this.changedForms = true; }, setUnchanged: function(){ this.changedForms = false; }, observeChange: function(element){ element.observe('change',this.setChanged.bindAsEventListener(this)); }, submitAction: function(element){ element.observe('submit',this.setUnchanged.bindAsEventListener(this)); }});

/* * 1 - registers a callback which copies the csrf token into the * X-CSRF-Token header with each ajax request. Necessary to * work with rails applications which have fixed * CVE-2011-0447 * 2 - shows and hides ajax indicator */Ajax.Responders.register({ onCreate: function(request){ var csrf_meta_tag = $$('meta[name=csrf-token]')[0];

if (csrf_meta_tag) { var header = 'X-CSRF-Token', token = csrf_meta_tag.readAttribute('content');

if (!request.options.requestHeaders) { request.options.requestHeaders = {}; } request.options.requestHeaders[header] = token; }

if ($('ajax-indicator') && Ajax.activeRequestCount > 0) { Element.show('ajax-indicator'); } }, onComplete: function(){ if ($('ajax-indicator') && Ajax.activeRequestCount == 0) { Element.hide('ajax-indicator'); } }});

function hideOnLoad() { $$('.hol').each(function(el) { el.hide(); });}

Event.observe(window, 'load', hideOnLoad);

The Problem #2

Do we really know(and love?)

JavaScript?

Sample JavaScript(from RailsCasts #267)

var CreditCard = { cleanNumber: function(number) { return number.replace(/[- ]/g, ""); },

validNumber: function(number) { var total = 0; number = this.cleanNumber(number); for (var i=number.length-1; i >= 0; i--) { var n = parseInt(number[i]); if ((i+number.length) % 2 == 0) { n = n*2 > 9 ? n*2 - 9 : n*2; } total += n; }; return total % 10 == 0; }};

console.log(CreditCard.validNumber('4111 1111-11111111')); // trueconsole.log(CreditCard.validNumber('4111111111111121')); // false

We see as this“ugly” Ruby

CreditCard = { :cleanNumber => lambda { |number| return number.gsub(/[- ]/, ""); }, :validNumber => lambda { |number| total = 0; number = CreditCard[:cleanNumber].call(number); for i in 0..(number.length-1) n = number[i].to_i; if ((i+number.length) % 2 == 0) n = n*2 > 9 ? n*2 - 9 : n*2; end total += n; end; return total % 10 == 0; }};

puts(CreditCard[:validNumber].call('4111 1111-11111111')); # trueputs(CreditCard[:validNumber].call('4111111111111121')); # false

Or as this “normal” Rubymodule CreditCard def self.clean_number(number) number.gsub(/[- ]/, "") end

def self.valid_number?(number) total = 0 number = clean_number(number) for i in 0...number.length n = number[i].to_i if i+number.length % 2 == 0 n = n*2 > 9 ? n*2 - 9 : n*2 end total += n end total % 10 == 0 endend

puts CreditCard.valid_number?('4111 1111-11111111') # trueputs CreditCard.valid_number?('4111111111111121') # false

“Best practices” Rubyclass CreditCard def initialize(number) @number = clean_number(number) end

def valid? total = 0 for i in [email protected] n = @number[i].to_i if [email protected] % 2 == 0 n = n*2 > 9 ? n*2 - 9 : n*2 end total += n end total % 10 == 0 end

private

def clean_number(number) number.gsub(/[- ]/, "") endend

puts CreditCard.new('4111 1111-11111111').valid? # trueputs CreditCard.new('4111111111111121').valid? # false

JavaScript has objects too!var CreditCard = function(number) { function cleanNumber(number) { return number.replace(/[- ]/g, ""); } this.number = cleanNumber(number);};

CreditCard.prototype = { isValid: function() { var total = 0; for (var i=this.number.length-1; i >= 0; i--) { var n = parseInt(this.number[i]); if ((i+this.number.length) % 2 == 0) { n = n*2 > 9 ? n*2 - 9 : n*2; } total += n; }; return total % 10 == 0; }};

console.log( (new CreditCard('4111 1111-11111111')).isValid() ); // trueconsole.log( (new CreditCard('4111111111111121')).isValid() ); // false

But this would be much more Ruby-like!

class CreditCard cleanNumber = (number) -> number.replace /[- ]/g, ""

constructor: (number) -> @number = cleanNumber number

isValid: (number) -> total = 0 for i in [[email protected]] n = +@number[i] if ([email protected]) % 2 == 0 n = if n*2 > 9 then n*2 - 9 else n*2 total += n total % 10 == 0

console.log (new CreditCard '4111 1111-11111111').isValid() # trueconsole.log (new CreditCard '4111111111111121').isValid() # false

Sample CoffeeScript# Assignment:number = 42opposite = true

# Conditions:number = -42 if opposite

# Functions:square = (x) -> x * x

# Arrays:list = [1, 2, 3, 4, 5]

# Objects:math = root: Math.sqrt square: square cube: (x) -> x * square x

# Splats:race = (winner, runners...) -> print winner, runners

# Existence:alert "I knew it!" if elvis?

# Array comprehensions:cubes = (math.cube num for num in list)

Functionssquare = (x) -> x * xcube = (x) -> square(x) * x

fill = (container, liquid = "coffee") -> "Filling the #{container} with #{liquid}..."

awardMedals = (first, second, others...) -> gold = first silver = second rest = others

contenders = [ "Michael Phelps" "Liu Xiang" "Yao Ming" "Allyson Felix" "Shawn Johnson"]

awardMedals contenders...

Objects and Arrayssong = ["do", "re", "mi", "fa", "so"]

singers = {Jagger: "Rock", Elvis: "Roll"}

bitlist = [ 1, 0, 1 0, 0, 1 1, 1, 0]

kids = brother: name: "Max" age: 11 sister: name: "Ida" age: 9

Variable Scope

outer = 1changeNumbers = -> inner = -1 outer = 10inner = changeNumbers()

var changeNumbers, inner, outer;outer = 1;changeNumbers = function() { var inner; inner = -1; return outer = 10;};inner = changeNumbers();

Existential Operator

solipsism = true if mind? and not world?

speed ?= 75

footprints = yeti ? "bear"

zip = lottery.drawWinner?().address?.zipcode

Conditionals

mood = greatlyImproved if singing

if happy and knowsIt clapsHands() chaChaCha()else showIt()

date = if friday then sue else jill

options or= defaults

Loops

eat food for food in ['toast', 'cheese', 'wine']countdown = (num for num in [10..1])

earsOld = max: 10, ida: 9, tim: 11ages = for child, age of yearsOld child + " is " + age

Classes, Inheritance and super

class Animal constructor: (@name) ->

move: (meters) -> alert @name + " moved " + meters + "m."

class Snake extends Animal move: -> alert "Slithering..." super 5

class Horse extends Animal move: -> alert "Galloping..." super 45

sam = new Snake "Sammy the Python"tom = new Horse "Tommy the Palomino"

sam.move()tom.move()

Function Binding

Account = (customer, cart) -> @customer = customer @cart = cart

$('.shopping_cart').bind 'click', (event) => @customer.purchase @cart

And many othernice features...

How to install?

brew install node # or install node.js otherwisecurl http://npmjs.org/install.sh | shnpm install -g coffee-script

Back to theProblem #1

Dynamic single page application

AppView

Identifying components

AppView


TodoViewTodoViewTodoView

AppView



keypress event

click event

click eventdblclick event

TodoList

AppView

Browser-sideViews and Models


keypress event

click event


TodoTodoTodo

TodoList

AppView



keypress event

click event


TodoTodoTodo

new, fetch

create, save

TodoList

AppView



keypress event

click event


TodoTodoTodo

refresh, add

change, destroy

TodoList

Browser-side Models and RESTful resources

TodoTodoTodo

TodosControllerindexshowcreateupdatedestroy

GET

JSON

POST

PUT

DELETE

Browser Rails

Organize CoffeeScript and JavaScript Code

using http://github.com/Sutto/barista

application.coffee

# main namespacewindow.TodoApp = {}

Todo modelclass TodoApp.Todo extends Backbone.Model

# If you don't provide a todo, one will be provided for you. EMPTY: "empty todo..."

# Ensure that each todo created has `content`. initialize: -> unless @get "content" @set content: @EMPTY

# Toggle the `done` state of this todo item. toggle: -> @save done: not @get "done"

TodoList collectionclass TodoApp.TodoList extends Backbone.Collection

# Reference to this collection's model. model: TodoApp.Todo

# Save all of the todo items under the `"todos"` namespace. url: '/todos'

# Filter down the list of all todo items that are finished. done: -> @filter (todo) -> todo.get 'done'

# Filter down the list to only todo items that are still not finished. remaining: -> @without this.done()...

# We keep the Todos in sequential order, despite being saved by unordered # GUID in the database. This generates the next order number for new items. nextOrder: -> if @length then @last().get('order') + 1 else 1

# Todos are sorted by their original insertion order. comparator: (todo) -> todo.get 'order'

Todo item viewclass TodoApp.TodoView extends Backbone.View # ... is a list tag. tagName: "li"

# Cache the template function for a single item. template: TodoApp.template '#item-template'

# The DOM events specific to an item. events: "click .check" : "toggleDone" "dblclick div.todo-content" : "edit" "click span.todo-destroy" : "destroy" "keypress .todo-input" : "updateOnEnter"

# The TodoView listens for changes to its model, re-rendering. Since there's # a one-to-one correspondence between a **Todo** and a **TodoView** in this # app, we set a direct reference on the model for convenience. initialize: -> _.bindAll this, 'render', 'close' @model.bind 'change', @render @model.bind 'destroy', => @remove()

# Re-render the contents of the todo item. render: -> $(@el).html @template @model.toJSON() @setContent() this

# To avoid XSS (not that it would be harmful in this particular app), # we use `jQuery.text` to set the contents of the todo item. setContent: -> content = @model.get 'content' @$('.todo-content').text content @input = @$('.todo-input') @input.blur @close @input.val content

# Toggle the `"done"` state of the model. toggleDone: -> @model.toggle()

# Switch this view into `"editing"` mode, displaying the input field. edit: -> $(@el).addClass "editing" @input.focus()

# Close the `"editing"` mode, saving changes to the todo. close: -> @model.save content: @input.val() $(@el).removeClass "editing"

# If you hit ènter`, we're through editing the item. updateOnEnter: (e) -> @close() if e.keyCode == 13

# Destroy the model. destroy: -> @model.destroy()

Todo item view

class TodoApp.TodoView extends Backbone.View # ... is a list tag. tagName: "li"

# Cache the template function for a single item. template: TodoApp.template '#item-template'

# The DOM events specific to an item. events: "click .check" : "toggleDone" "dblclick div.todo-content" : "edit" "click span.todo-destroy" : "destroy" "keypress .todo-input" : "updateOnEnter"

# The TodoView listens for changes to its model, re-rendering. Since there's # a one-to-one correspondence between a **Todo** and a **TodoView** in this # app, we set a direct reference on the model for convenience. initialize: -> _.bindAll this, 'render', 'close' @model.bind 'change', @render @model.bind 'destroy', => @remove()

# Re-render the contents of the todo item. render: -> $(@el).html @template @model.toJSON() @setContent() this

# To avoid XSS (not that it would be harmful in this particular app), # we use `jQuery.text` to set the contents of the todo item. setContent: -> content = @model.get 'content' @$('.todo-content').text content @input = @$('.todo-input') @input.blur @close @input.val content

# Toggle the `"done"` state of the model. toggleDone: -> @model.toggle()

# Switch this view into `"editing"` mode, displaying the input field. edit: -> $(@el).addClass "editing" @input.focus()

# Close the `"editing"` mode, saving changes to the todo. close: -> @model.save content: @input.val() $(@el).removeClass "editing"

# If you hit ènter`, we're through editing the item. updateOnEnter: (e) -> @close() if e.keyCode == 13

# Destroy the model. destroy: -> @model.destroy()

Application viewclass TodoApp.AppView extends Backbone.View

# Instead of generating a new element, bind to the existing skeleton of # the App already present in the HTML. el: "#todoapp"

# Our template for the line of statistics at the bottom of the app. statsTemplate: TodoApp.template '#stats-template'

# Delegated events for creating new items, and clearing completed ones. events: "keypress #new-todo" : "createOnEnter" "keyup #new-todo" : "showTooltip" "click .todo-clear a" : "clearCompleted"

# At initialization we bind to the relevant events on the `Todos` # collection, when items are added or changed. Kick things off by # loading any preexisting todos that might be saved. initialize: -> _.bindAll this, 'addOne', 'addAll', 'renderStats'

@input = @$("#new-todo")

@collection.bind 'add', @addOne @collection.bind 'refresh', @addAll @collection.bind 'all', @renderStats

@collection.fetch()

# Re-rendering the App just means refreshing the statistics -- the rest # of the app doesn't change. renderStats: -> @$('#todo-stats').html @statsTemplate total: @collection.length done: @collection.done().length remaining: @collection.remaining().length

# Add a single todo item to the list by creating a view for it, and # appending its element to the `<ul>`. addOne: (todo) -> view = new TodoApp.TodoView model: todo @$("#todo-list").append view.render().el

# Add all items in the collection at once. addAll: -> @collection.each @addOne

# Generate the attributes for a new Todo item. newAttributes: -> content: @input.val() order: @collection.nextOrder() done: false

# If you hit return in the main input field, create new **Todo** model, # persisting it to server. createOnEnter: (e) -> if e.keyCode == 13 @collection.create @newAttributes() @input.val ''

# Clear all done todo items, destroying their views and models. clearCompleted: -> todo.destroy() for todo in @collection.done() false

# Lazily show the tooltip that tells you to press ènter` to save # a new todo item, after one second. showTooltip: (e) -> tooltip = @$(".ui-tooltip-top") val = @input.val() tooltip.fadeOut() clearTimeout @tooltipTimeout if @tooltipTimeout unless val == '' or val == @input.attr 'placeholder' @tooltipTimeout = _.delay -> tooltip.show().fadeIn() , 1000

Application view

class TodoApp.AppView extends Backbone.View







@collection.fetch()








Application view

class TodoApp.AppView extends Backbone.View







@collection.fetch()








index.html.haml#todoapp .title %h1 Todos .content #create-todo %input#new-todo{:placeholder => "What needs to be done?", :type => "text"}/ %span.ui-tooltip-top{:style => "display:none;"} Press Enter to save this task #todos %ul#todo-list #todo-stats%ul#instructions %li Double-click to edit a todo.

:coffeescript $ -> TodoApp.appView = new TodoApp.AppView collection: new TodoApp.TodoList

%script#item-template{:type => "text/html"} .todo{:class => "{{#done}}done{{/done}}"} .display %input{:class => "check", :type => "checkbox", :"{{#done}}checked{{/done}}" => true} .todo-content %span.todo-destroy .edit %input.todo-input{:type => "text", :value => ""}

%script#stats-template{:type => "text/html"} {{#if total}} %span.todo-count %span.number {{remaining}} %span.word {{pluralize remaining "item"}} left. {{/if}} {{#if done}} %span.todo-clear %a{:href => "#"} Clear %span.number-done {{done}} completed %span.word-done {{pluralize done "item"}} {{/if}}

index.html.haml

#todoapp .title %h1 Todos .content #create-todo %input#new-todo{:placeholder => "What needs to be done?", :type => "text"}/ %span.ui-tooltip-top{:style => "display:none;"} Press Enter to save this task #todos %ul#todo-list #todo-stats%ul#instructions %li Double-click to edit a todo.

:coffeescript $ -> TodoApp.appView = new TodoApp.AppView collection: new TodoApp.TodoList

%script#item-template{:type => "text/html"} .todo{:class => "{{#done}}done{{/done}}"} .display %input{:class => "check", :type => "checkbox", :"{{#done}}checked{{/done}}" => true} .todo-content %span.todo-destroy .edit %input.todo-input{:type => "text", :value => ""}

%script#stats-template{:type => "text/html"} {{#if total}} %span.todo-count %span.number {{remaining}} %span.word {{pluralize remaining "item"}} left. {{/if}} {{#if done}} %span.todo-clear %a{:href => "#"} Clear %span.number-done {{done}} completed %span.word-done {{pluralize done "item"}} {{/if}}

One more thing:Backbone Controllersclass Workspace extends Backbone.Controller

routes: "help" : "help" #help "search/:query" : "search" #search/kiwis "search/:query/p:page": "search" #search/kiwis/p7

help: -> ...

search: (query, page) -> ...

RoutersRouter

How do you test it?

RSpec-like testing for JavaScript

Together with all other tests

Testing Todo modeldescribe "Todo", -> todo = null ajaxCall = (param) -> jQuery.ajax.mostRecentCall.args[0][param]

beforeEach -> todo = new TodoApp.Todo todos = new TodoApp.TodoList [todo]

it "should initialize with empty content", -> expect(todo.get "content").toEqual "empty todo..."

it "should initialize as not done", -> expect(todo.get "done").toBeFalsy()

it "should save after toggle", -> spyOn jQuery, "ajax" todo.toggle() expect(ajaxCall "url").toEqual "/todos" expect(todo.get "done").toBeTruthy()

and TodoList collection

describe "TodoList", -> attributes = [ content: "First" done: true , content: "Second" ] todos = null

beforeEach -> todos = new TodoApp.TodoList attributes it "should return done todos", -> expect(_.invoke todos.done(), "toJSON").toEqual [attributes[0]]

it "should return remaining todos", -> expect(_.invoke todos.remaining(), "toJSON").toEqual [attributes[1]]

Rails 3.1Asset Pipeline

application.js.coffeeusing Sprockets

#= require jquery#= require underscore#= require backbone#= require handlebars#= require ./todo_app#= require_tree ./models#= require ./views/helpers#= require_tree ./views

Watch RailsConfDHH keynote

http://en.oreilly.com/rails2011/public/schedule/detail/19068



References

http://jashkenas.github.com/coffee-script/

http://documentcloud.github.com/backbone/

http://pivotal.github.com/jasmine/

https://github.com/rsim/backbone_coffeescript_demo

Used in eazybi.com

Documents

Rails-like JavaScript Using CoffeeScript, Backbone.js and Jasmine