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Fundamentals of Web Development 
Fundamentals of Web Development Randy Connolly and Ricardo Hoar 
Textbook	to	be	published	by	Pearson	Ed	in	early	2014	
h:p://www.funwebdev.com	
		©	2015	Pearson
Advanced 
JavaScript & 
JQuery 
Chapter	15	
Fundamentals of Web Development 
Objectives 
JavaScript 
Pseudo-Classes 
jQuery 
Foundations 
AJAX 
1 2
3
7
Animation 5
Asynchronous 
File Transmission 4
Backbone MVC 
Frameworks 6
Fundamentals of Web Development 
JAVASCRIPT PSEUDO-CLASSES 
Section 1 of 6 
Fundamentals of Web Development 
Object Oriented Design 
•  JavaScript	has	no	formal	class	mechanism.	
•  Many	common	features	of	object-oriented	
programming,	such	as	inheritance	and	even	simple	
methods,	must	be	arrived	at	through	these	
nonintuiMve	means.	
•  These	“strange”	techniques	give	JavaScript	a	bad	
reputaMon,	but	can	easily	be	mastered.	
Without Classes 
Fundamentals of Web Development 
Using Object Literals 
An	object	can	be	instanMated	using	object	literals.	
Object	literals	are	a	list	of	key-value	pairs	with	colons	
between	the	key	and	value	with	commas	separaMng	
key-value	pairs.		
Object	literals	are	also	known	as	Plain	Objects	in	
jQuery.	
Without Classes 
Fundamentals of Web Development 
Using Object Literals 
An	object	can	be	instanMated	using	object	literals.	
Object	literals	are	also	known	as	Plain	Objects	in	
jQuery.	
Object	literals	are	a	list	of	key-value	pairs	with	colons	
between	the	key	and	value	with	commas	separaMng	
key-value	pairs.		
Without Classes 
Fundamentals of Web Development 
Using Object Literals 
//define	a	6	faced	dice,	with	a	red	color.	
var	oneDie	=	 	{	color	:	"FF0000",		
	 				faces	:	[1,2,3,4,5,6]		
	 	};	
These	elements	can	be	accessed	using	dot	notaMon.	
For	instance,	one	could	change	the	color	to	blue	by	
wriMng:	
oneDie.color="0000FF";	
	
	
Consider a die (single dice) 
Fundamentals of Web Development 
Emulate Classes with functions 
It	is	possible	to	mimic	many	features	of	classes	by	
using	funcMons	to	encapsulate	variables	and	methods	
together.	
	
	
We told you this would get weird 
Fundamentals of Web Development 
Emulate Classes with functions 
It	is	possible	to	mimic	many	features	of	classes	by	
using	funcMons	to	encapsulate	variables	and	methods	
together.	
	
	
	
	
InstanMaMon	looks	much	like	in	PHP:	
var	oneDie	=	new	Die("0000FF");	
	
	
We told you this would get weird 
Fundamentals of Web Development 
Emulate Classes with functions 
One	technique	for	adding	a	method	inside	of	a	class	
definiMon	is	by	assigning	an		anonymous	funcMon	to	a	
variable	
	
Add methods to the object – mimic methods 
Fundamentals of Web Development 
Emulate Classes with functions 
One	technique	for	adding	a	method	inside	of	a	class	
definiMon	is	by	assigning	an		anonymous	funcMon	to	a	
variable	
	
	
	
	
	
	
var	oneDie	=	new	Die("0000FF");	
console.log(oneDie.randomRoll()	+	"	was	rolled");	
	
Add methods to the object – mimic methods 
Fundamentals of Web Development 
Emulate Classes with functions 
Defining	methods	as	we	have	shown	is	not	a	memory-
efficient	approach	because	each	inline	method	is	
redefined	for	each	new	object!	
	
Not very efficient 
Fundamentals of Web Development 
Using Prototypes 
A	be:er	approach	is	to	define	the	method	just	once	
using	a	prototype	of	the	class.	
•  Prototypes	are	used	to	make	JavaScript	behave	
more	like	an	object-oriented	language.	
•  The	prototype	properMes	and	methods	are	defined	
once	for	all	instances	of	an	object.	
•  Every	object	has	a	prototype	
Prototypes 
Fundamentals of Web Development 
Using Prototypes 
moving the randomRoll() function into the prototype. 
Fundamentals of Web Development 
Using Prototypes 
No duplication of methods 
Since	all	instances	of	a	Die	share	the	same	prototype	
object,	the	funcMon	declaraMon	only	happens	one	
Mme	and	is	shared	with	all	Die	instances.	
Fundamentals of Web Development 
More about Prototypes 
There’s more? 
It	should	be	known	that	every	object	(and	method)	in	
JavaScript	has	a	prototype.	
A	prototype	is	an	object	from	which	other	objects	
inherit.	
The	above	definiMon	sounds	almost	like	a	class	in	
an	object-oriented	language,	except	that	a	
prototype	is	itself	an	object,	not	an	abstracMon	
Fundamentals of Web Development 
More about Prototypes 
Extend any Object 
In	addiMon	to	using	prototypes	for	our	own	pseudo-
classes,	prototypes	enable	you	to	extend	exisMng	
classes	by	adding	to	their	prototypes!	
	
Below	we	extend	String:	
	
Fundamentals of Web Development 
More about Prototypes 
Extending String, for example 
Now	any	new	instances	of	String	will	have	this	method	
available	to	them	while	exisMng	strings	will	not.		
Now	we	can	use	the	new	method	in	all	new	Strings.	
The	following	example	will	output		
Hello	World	has	3	le	element	with	
id="grab"	you	would	write:	
var	singleElement	=	$("#grab");	
To	get	a	set	of	all	the		elements	the	selector	would	be:	
var	allAs	=	$("a");	
	
These	selectors	replace	the	use	of	getElementById()	
enMrely.	
Fundamentals of Web Development 
More CSS Selectors 
jQuery’s selectors are powerful indeed 
In	addiMon	to	these	basic	selectors,	you	can	use	the	
other	CSS	selectors	that	were	covered	in	Chapter	3	on	
CSS:		
•  a:ribute	selectors,		
•  pseudo-element	selectors,	and		
•  contextual	selectors	
Fundamentals of Web Development 
More CSS Selectors 
jQuery’s selectors are powerful indeed 
Fundamentals of Web Development 
Attribute Selector 
Really a review of CSS 
Recall	from	CSS	that	you	can	select		
•  by	a:ribute	with	square	brackets		
•  [a:ribute]	
•  Specify	a	value	with	an	equals	sign		
•  [a:ribute=value]	
•  Search	for	a	parMcular	value	in	the	beginning,	end,	or	
anywhere	inside	a	string		
•  [a:ribute^=value]	
•  [a:ribute$=value]	
•  [a:ribute*=value]	
Fundamentals of Web Development 
Attribute Selector 
Really a review of CSS 
Consider	a	selector	to	grab	all		elements	with	an	
src	a:ribute	beginning	with	/ar?st/	as:	
var	arWstImages	=	$("img[src^='/arWst/']");	
Fundamentals of Web Development 
Pseudo-Element Selector 
Not to be confused with the pseudo-classes in JavaScript 
pseudo-element	selectors	are	also	from	CSS	and	allow	you	
to	append	to	any	selector	using	the	colon	and	one	of	
•  :link	
•  :visited	
•  :focus	
•  :hover	
•  :acMve	
•  :checked	
•  :first-child,	:first-line,	and	:first-le:er	
Fundamentals of Web Development 
Pseudo-Element Selector 
Not to be confused with the pseudo-classes in JavaScript 
SelecMng	all	links	that	have	been	visited,	for	example,	
would	be	specified	with:	
var	visitedLinks	=	$("a:visited");	
Fundamentals of Web Development 
Contextual Selector 
Put it into context 
Contextual	selectors	are	also	from	CSS.	Recall	that	
these	include:	
•  descendant	(space)	
•  child	(>)	
•  adjacent	sibling	(+)	
•  and	general	sibling	(~).	
To	select	all	
	elements	inside	of	
	elements	
you	would	write	
var	para	=	$("div	p");	
Fundamentals of Web Development 
Content Filters 
The	content	filter	is	the	only	jQuery	selector	that	
allows	you	to	append	filters	to	all	of	the	selectors	
you’ve	used	thus	far	and	match	a	parMcular	pa:ern.	
Select	elements	that	have:	
•  a	parMcular	child	using	:has()	
•  have	no	children	using	:empty	
•  match	a	parMcular	piece	of	text	with	:contains()	
Above and Beyond CSS 
Fundamentals of Web Development 
Content Filters 
$("body	*:contains('warning')”)	
Above and Beyond CSS 
Fundamentals of Web Development 
Form Selectors 
Above and Beyond CSS 
Selector	 CSS	Equivalent	 DescripWon	
$(:bu:on)	 $("bu:on,	input[type='bu:on']")		 Selects	all	bu:ons	
$(:checkbox)	 $('[type=checkbox]‘)	 Selects	all	checkboxes	
$(:checked)	 No	Equivalent	 Selects	elements	that	are	checked.	This	includes	radio	bu:ons	
and	checkboxes.	
$(:disabled)	 No	Equivalent	 Selects	form	elements	that	are	disabled.		
$(:enabled)	 No	Equivalent	 Opposite	of	:disabled	
$(:file)	 $('[type=file]')		 Selects	all	elements	of	type	file	
$(:focus)	 $(	document.acMveElement	)		 The	element	with	focus	
$(:image)	 $('[type=image]')	 Selects	all	elements	of	type	image 
$(:input)	 No	Equivalent	 Selects	all	,