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
Identifying components
TodoViewTodoViewTodoView
AppView
Identifying components
TodoViewTodoViewTodoView
keypress event
click event
click eventdblclick event
TodoList
AppView
Browser-sideViews and Models
TodoViewTodoViewTodoView
keypress event
click event
click eventdblclick event
TodoTodoTodo
TodoList
AppView
Browser-sideViews and Models
TodoViewTodoViewTodoView
keypress event
click event
click eventdblclick event
TodoTodoTodo
new, fetch
create, save
TodoList
AppView
Browser-sideViews and Models
TodoViewTodoViewTodoView
keypress event
click event
click eventdblclick 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 `enter`, 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() $(@el).removeClass "editing"
# If you hit `enter`, we're through editing the item. updateOnEnter: (e) -> @close() if e.keyCode == 13
# Destroy the model. destroy: -> @model.destroy()
Application viewclass TodoApp.AppView extends Backbone.View
# Instead of generating a new element, bind to the existing skeleton of # the App already present in the HTML. el: "#todoapp"
# Our template for the line of statistics at the bottom of the app. statsTemplate: TodoApp.template '#stats-template'
# Delegated events for creating new items, and clearing completed ones. events: "keypress #new-todo" : "createOnEnter" "keyup #new-todo" : "showTooltip" "click .todo-clear a" : "clearCompleted"
# At initialization we bind to the relevant events on the `Todos` # collection, when items are added or changed. Kick things off by # loading any preexisting todos that might be saved. initialize: -> _.bindAll this, 'addOne', 'addAll', 'renderStats'
@input = @$("#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 `enter` to save # a new todo item, after one second. showTooltip: (e) -> tooltip = @$(".ui-tooltip-top") val = @input.val() tooltip.fadeOut() clearTimeout @tooltipTimeout if @tooltipTimeout unless val == '' or val == @input.attr 'placeholder' @tooltipTimeout = _.delay -> tooltip.show().fadeIn() , 1000
Application view
class TodoApp.AppView extends Backbone.View
# Instead of generating a new element, bind to the existing skeleton of # the App already present in the HTML. el: "#todoapp"
# Our template for the line of statistics at the bottom of the app. statsTemplate: TodoApp.template '#stats-template'
# Delegated events for creating new items, and clearing completed ones. events: "keypress #new-todo" : "createOnEnter" "keyup #new-todo" : "showTooltip" "click .todo-clear a" : "clearCompleted"
# At initialization we bind to the relevant events on the `Todos` # collection, when items are added or changed. Kick things off by # loading any preexisting todos that might be saved. initialize: -> _.bindAll this, 'addOne', 'addAll', 'renderStats'
@input = @$("#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 `enter` to save # a new todo item, after one second. showTooltip: (e) -> tooltip = @$(".ui-tooltip-top") val = @input.val() tooltip.fadeOut() clearTimeout @tooltipTimeout if @tooltipTimeout unless val == '' or val == @input.attr 'placeholder' @tooltipTimeout = _.delay -> tooltip.show().fadeIn() , 1000
Application view
class TodoApp.AppView extends Backbone.View
# Instead of generating a new element, bind to the existing skeleton of # the App already present in the HTML. el: "#todoapp"
# Our template for the line of statistics at the bottom of the app. statsTemplate: TodoApp.template '#stats-template'
# Delegated events for creating new items, and clearing completed ones. events: "keypress #new-todo" : "createOnEnter" "keyup #new-todo" : "showTooltip" "click .todo-clear a" : "clearCompleted"
# At initialization we bind to the relevant events on the `Todos` # collection, when items are added or changed. Kick things off by # loading any preexisting todos that might be saved. initialize: -> _.bindAll this, 'addOne', 'addAll', 'renderStats'
@input = @$("#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 `enter` 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
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