Training javascript 2012 hcmut

TRAINING JAVASCRIPT & jQUERY

Editor: Nguyễn Đức Minh Khôi
Email: nguyenducminhkhoi@gmail.com
HCMC University of Technology
@Jan, 2012

Content
Introduction to JavaScript

JavaScript – the basic

Getting Started with JQuery

JQuery in Action

Ajax, tips, tricks

2 1/6/2012

Part1: Introduction to JavaScript

What is JavaScript and JQuery?

The Web World

Software for JavaScript programming

3 1/6/2012

What is JavaScript?
 JavaScript is a programming language that lets you
supercharge your HTML with animation, interactivity,
and dynamic visual effects.

4 1/6/2012

What is jQuery?
 jQuery is a JavaScript library intended to make
JavaScript programming easier and more fun.
 solves the two biggest headaches with JavaScript—
complexity and the finicky nature of different web
browsers.
 you can add advanced features to your website with
thousands of easy-to-use jQuery plug-ins.

5 1/6/2012

The web world
 HTML provides the structural layer, organizing content
like pictures and words in a meaningful way
 CSS (Cascading Style Sheets) provides the
presentational layer, making the content in the HTML
look good
 JavaScript adds a behavioral layer, bringing a web page
to life so it interacts with web visitors and reduce
“stress” for Server.
 Other Server Scripting: PHP, ASP, JSP, Ruby, Python…
do the main part of your project!

6 1/6/2012

Software for JS Programming
 Notepad++ (Windows, http://notepad-plus-plus.org) is a
coder’s friend.
 Netbeans (Windows, Linux, Mac; www.eclipse.org) is a
free, popular choice amongst Java Developers, but
includes tools for working with HTML, CSS, and JavaScript.
 Eclipse and Aptana Studio plugin (Windows, Linux, Mac;
www.aptana.org) is a powerful, free coding environment
with tools for working with HTML, CSS, JavaScript, PHP, and
Ruby on Rails.
 Dreamweaver (Mac and Windows,
www.adobe.com/products/dreamweaver.html) is a visual
web page editor.
 Expression Web Designer (Windows,
www.microsoft.com/expression/products/StudioWebPro_
Overview.aspx) is Microsoft’s entry in the web design field.
7 1/6/2012

Software for JS Programming (cont’)
 Google Chrome browser and Developer tools (Ctr +
Shift + J)
 Firefox and firebug plugin (http://getfirebug.com/)
 Internet Explorer 9 – console (F12)
 Safari and Error console (Ctrl + Alt + C)
 Wamp Server (for Ajax practice) for windows
www.wampserver.com/en/
 Lamp Server for Linux (Debian, Ubuntu)
http://www.sph.umich.edu/csg/abecasis/LAMP/downl
oad/
 Mamp Server for Mac: www.mamp.info/en

8 1/6/2012

Content



JQuery in Action

Ajax, tips, tricks

10 1/6/2012

Part2: JavaScript – the Basics


How to work with JavaScript

11 1/6/2012

 How to add JS to a page:

Notes: if you use HTML earlier than HTML5 should:

12 1/6/2012

Introduction to JavaScript (cont.)
 URL type:
 Absolute path:
 http://www.cosmofarmer.com/scripts/site.js
 Use when you point to a file that’s not on the same server as the
your web page.
 Root relative:
 /scripts/site.js
 Use for JavaScript files stored on your own site.
 Document relative:
 ../scripts/site.js - ../ means climb up out of the folder
 Use when you’re designing on your own computer without the
aid of a web server.

13 1/6/2012

 JS is a client-side language which means that it works
inside a web browser.
 JS is also a scripting language like PHP, Ruby, Python
ColdFusion as well.
 JS is a multi-paradigm language, supporting object-
oriented, imperative, and functional programming styles.
 JavaScript was formalized in the ECMAScript language
standard.
 JavaScript uses syntax influenced by that of C. And very
different sematic with Java.
 See more at http://www.w3schools.com/js/default.asp

14 1/6/2012

 Statement
 Basic programming unit
 E.g.: alert('Hello World!');
 Popup Box:
 alert(‚Be alert‛) // alert something with user
 prompt(‚enter sth‛)//ask user to input something
 confirm("Press a button!");
 Built in function
 document.write() //add content to a page
 isNaN(variable) //check if variable is a number
 Number(variable) // convert to number or NaN
 String(variable) // convert to string
 Data Type
 Number: 5, 5.125, NaN (just– Double)
 String: ‘Hello’, ‚Hello‛, ‚Hello ’World’ !‛, ‚’a‛,
‚Hello‛World‛!‛
 Boolean: true, false
 Object
15  null, undefined 1/6/2012

 Variable
 Declare: var + varName;
 Name: abc ≠ Abc, $abc, _abc, a123, 1bcd, alert
 Assign: varName = value;
 Show values: alert(varName);
 Operation:
 Boolean op: ==, != , ===, !==, >, < , >=, <=, &&, ||, !
 Number op: 3 + 4, 3 / 4, 3 * 4, 3 – 4
 String op: ‘abc’ + ‘def’;
 Mix: ‘12’ + 4 = ‘124’; +’123’ + 4 = 127;
Number(‘123’) + 4 = 127; ‘12’ * 4 = 48;
 Complex op: ++, --, *=, /=, +=, -=
 Ternary op: (condition) ? A : B

16 1/6/2012

 Comment:
 //this is a comment inline
 /*
something to comment in many lines
*/
 Array (List in real)
 Declare: var arr = [1, 2, 3]; or
var arr = new Array(1, 2, 3);
 Access: arr[0];
 Notes:
 Empty array: var arr = [];
 Mix types: var arr = [1, 2, ‘abc’, true, [3, 4,5]];

17 1/6/2012

 Array op:

18 1/6/2012

 If Statement: if ( condition1 ) {
// door #1
} else if (condition2) {
// door #2
} else {
// door #3
}
 Switch Statement:
switch(n)
{
case 1:
execute code block 1
break;
case 2:
execute code block 2
break;
default:
code to be executed if n is different from case 1 and 2
19 1/6/2012
}

 While Statement:
while (condition) {
// javascript to repeat
}
 Do while Statement:
do {
} while (condition) ;
 For Statement:
for (var count = 0; count < MaxLoop; count++){
}

20 1/6/2012

Introduction to JavaScript (cont’)
 Break Statement:
while (condition) {
if (i==3){
break;
}
}
 Continue Statement:
do {
if (i==3){
continue;
}
} while (condition) ;
 For in Statement:
for (variable in object){
code to be executed
}
21 1/6/2012

 Function:
function functionName(parameters){
// the JavaScript you want to run
return value;
}
 Anonymous function: (lambda function)
function (parameter1, parameter2){
// the JavaScript you want to run
return value;
}

22 1/6/2012

 Global vs. local variable:
var paramenter = 3;
function func1(){
alert(parameter); // alert(3)
var parameter = 5;
alert(parameter); // alert(5)
}
func1();
 Try, catch, throws:
try{
//Run some code here
throw ‚Error‛;
}
catch(err)
{
//Handle errors here
}
 Put variable as a reference definitions at the beginning of your script
23 1/6/2012

How to work with JavaScript?
 Work with String:
 Determine length of a string: strVar.length
 Changing case of a string: strVar.toUpperCase()
or strVar.toLowerCase()
 Searching String: strVar.indexOf(‘strSearch’)

 Extract part of a String:
strVar.slice(start, [end])

24 1/6/2012

How to work with JavaScript? (cont.)
 Work with Regular Expression:

25 1/6/2012

 Work with Regular Expression:
 Useful Regex:
 U.S. Zip code:

 U.S. Phone #:

 Email Address:

 Date:

 Web Address:

26 1/6/2012

 Work with Number:
 JavaScript interpreter usually converts a string to a
number when it seems like a number is called for. For
example: but:

 Number():

 ParseInt():

 ParseFloat():

 Test a Number:

27 1/6/2012

 Work with Number (next):
 Math.round(), Math.ceil(), Math.floor():

 Formatting currency:

 Creating Random number:

 Selecting random number:

 Selecting randomly element of array:

28 1/6/2012

 Work with Dates and Times:
 Declare:

29 1/6/2012

 Work with Dates and Times (next):
 Getting the month:

 Getting the Day of a week:

 Creating Day other than today:

30 1/6/2012

 Work with Dates and Times (next):
 Getting the time format (e.g.: 12:03:59 a.m.):

31 1/6/2012

Content


Getting Started with jQuery

jQuery in Action

Ajax, tips, tricks

33 1/6/2012

Part3:Getting Started with jQuery

Selecting Element of a page

Attach an Event to Elements

Response Events by doing sth

34 1/6/2012

Introduction to jQuery
 Why use jQuery?
 Relatively small file size
 Friendly to web designers
 It’s tried and true
 It’s free
 Large developer community
 Plugins
 How to use?
 Link to jQuery file on CDN server:
<script src=
"http://ajax.googleapis.com/ajax/libs/jquery/1.6.3
/jquery.m in.js"></script>
 Download jQuery file:
http://docs.jquery.com/Downloading_jQuery.
<script src="js/jquery-1.6.3.min.js"></script>
35 1/6/2012

Introduction to jQuery (cont.)
 Some useful jQuery plugin:
 jQuery-color: https://github.com/jquery/jquery-color
 jQuery-easing: http://gsgd.co.uk/sandbox/jquery/easing/
 JQuery-fancybox: http://fancybox.net/
 JQuery-scrollTo: http://plug-ins.jquery.com/project/ScrollTo
 jQuery-navigation: www.pollenizer.com/jquery-navigation-plugin/
 jQuery-UI: http://jqueryui.com/download
 jQuery-qTip: http://craigsworks.com/projects/qtip2/
 jQuery Raty - A Star Rating: http://www.wbotelhos.com/raty/
 jQuery Flickr: http://johnpatrickgiven.com/jquery/flickr-gallery/
 jQuery-Ajax Form plugins: http://jquery.malsup.com/form/
 jQuery-Ajax Autocomplete: http://jqueryui.com/demos/auto-
complete/
 jQuery-Ajax Uploadfile: http://www.uploadify.com/download/
 jQuery-Ajax twitter: http://tweet.seaofclouds.com/
36
 jQuery-Ajax Google Map: http://www.pittss.lv/jquery/gomap/ 1/6/2012

Selecting Element of a page
 Notes:
 put your JavaScript programming (all your <script> tags) after any
other content inside the <head> tag, but before the closing </head>
tag.
 <script>
$(document).ready(function() {
// your programming goes here
}); // end ready
</script>
Or use for short:
 <script>
$(function() {
// your programming goes here
}); // end ready
37 </script> 1/6/2012

Selecting Element of a page (cont.)

38 1/6/2012

 Select page element (examples)
 Basic Selector (like CSS selector)
 Id selector: var messagePara = $('#message');
 Tag selector: var linksList = $('a');
 Class selector: var a = $('.submenu');
 Advanced Selector
 Descendent selector: $('#navBar a')
 Child selector: $(‘body > p')
 Adjacent sibling selector: $('h2 + div')
 Attribute selector: $('img[alt]')
 jQuery filter
 $('p:first'); $('p:last'); $('p:odd');
$('p:even');
 $('a:not(.navButton)'); $('li:has(a)');
 $('a:contains(Click Me!)');
 $('div:hidden').show(); $('div:visible').show();

41 1/6/2012

 jQuery selection principles
 Automatic loops: $('#slideshow img').hide();
 Chaining function: $('#popUp').width(300).height(300);
 Useful functions:

42 1/6/2012

 $('#errors').html();
 $('#errors').html('<p>There are four errors in this form</p>');
 $('#errors h2').text('No errors found');
 $('#errors').append('<p>There are four errors in this form</p>');
 $('#errors').prepend('<p>There are four errors in this
form</p>');
 $('#userName').after('<span class="error">User name
required</span>');
 $('#product101').replaceWith(<p>Added to cart</p>');
 $('a[href^="http://"]').addClass('externalLink');
 $('#alertBox').removeClass('highlight');
 $('body').toggleClass('altStyle');
 $('#main').css('background-color');
 $('body').css('font-size', '200%');
 var imageFile = $('#banner img').attr('src');

46 $('body').removeAttr('bgColor'); 1/6/2012

 Notes:
 Changing Multiple CSS Properties at Once

 Each function:

$(this): element
loop through all
elements.

47 1/6/2012

Attach an Event to Elements
 Types of events:

48 1/6/2012

Attach an Event to Elements (cont)
 Using Event – the jQuery Way:

52 1/6/2012

Attach an Event to Elements- e.g.

53 1/6/2012

Response Events by doing sth
 jQuery Effects:

54 1/6/2012

Response Events by doing sth (cont.)
 Examples:

55 1/6/2012

 jQuery Animations:
 Some attr are built-in (no need plugins)
 Some attr need plugins:
 jquery-color: https://github.com/jquery/jquery-color
 jquery-easing: http://gsgd.co.uk/sandbox/jquery/easing/
 How to use:

56 1/6/2012

 Notes:
 with hyphens: in CSS use 1 of these:

 can use += or -= in CSS attr:

 No use shorthands:

57 1/6/2012

 Using Easing:

 Callback function: a
function that runs
only after the effect
is completed.

58 1/6/2012

Content


Getting Started with jQuery

jQuery in Action

Ajax, tips, tricks

60 1/6/2012

Part3: jQuery in Action
Improving your images

Improving navigation

Enhancing Web forms

Expanding your interfaces

61 1/6/2012

jQuery in Action
 Notes:
 var newPara = $(‘<p>Hello</p>’) creates a new
paragraph tag containing the word Hello.
 var $banner = $('#banner');
The dollar sign reminds you that the variable holds a
jQuery selection and not just any old value like a number
or a string.
 This part is just giving you some basic techniques to do with
jQuery, for more information, you should lookup some
tutorial in the main reference book “Java-jQuery the Missing
Manual” - Part 3. This will give you more clearly about this
techniques. And practice some tutorials in this books for
conquer the idea.
 You should download and see the usage of the plugins in
listed in the slide #34 of this slides.

62 1/6/2012

Improving your images
 Changing an Image’s src Attribute:

tells the web browser to actually
download the new image

 Preloading Images

63 1/6/2012

Improving your images (cont.)
 Rollover images:
 Just an image swap triggered by the mouse moving over
an image

64 1/6/2012

Improving navigation
 Open External links in new Windows:

 location.protocol stores the object’s protocol property like http or https
 location.hostname stores the object’s host name like www.google.com
 The not() function is a useful way of excluding some elements from a jQuery
selection
 Creating new Windows:

 to close:

65 1/6/2012

Improving navigation (cont.)
 Opening page within a page – fancy box plugin

 Navigation Bar Plugin

66 1/6/2012

Enhancing Web Forms
 Getting and Setting Form value Element:

 Determining Whether Buttons and Boxes Are Checked

Don’t do that or
not follow that
links
 Form events:
 Submit: validate
Username is input

67 1/6/2012

Enhancing Web Forms (Cont.)
 Focus: (input text, default value will disappear)

 Blur: (check recently input box is correct)

 Click:

 Change:

68 1/6/2012

Enhancing Web Forms (cont.)
 Adding smart to your form:
 Focus the first field in the form:

 Disabling and Enabling Fields:

 Hiding and Showing form option:

69 1/6/2012

Enhancing Web Forms (cont.)
 Form validation plugin
 Basic validation:
 Adding validation rules:

 Adding Error message:

 Advanced validation: (see more at the book)

70 1/6/2012

Expanding your Interface
 Organizing Information in Tabbed Panel
 Adding a Content Slider to Your site
 Determining the Size and Position of Page Element
 Adding Tooltips
 (See more at the book)

71 1/6/2012

Content



JQuery in Action

Ajax, tips, tricks

73 1/6/2012

Part3:Ajax, Tips and Tricks
What is Ajax?

JSON

Tips and tricks

74 1/6/2012

What is Ajax?
 stands for Asynchronous JavaScript and XML
 not an “official” technology like HTML, JavaScript, or CSS.
 refers to the interaction of a mix of technologies—JavaScript,
the web browser, and the web server—to retrieve and display
new content without loading a new web page
 What you can do with Ajax:
 Display new HTML content without reloading the page
 Submit a form and instantly display results
 Log in without leaving the page
 Star-rating widget
 Browsing through database information.

75 1/6/2012

What is Ajax? (cont.)
 Know more about web server:
 Web server: stores documents and when a web browser
asks for a document, the web server delivers it. (Apache,
IIS,…)
 Web application: understands a server-side
programming language like PHP, Java, Ruby, Python.
perform tasks that aren’t possible with only an HTML
page, like sending email, storing information in a
database.
 Web database: store information like the names and
addresses of customers, details of products you sell, or
an archive of your favorite recipes. (e.g.: MySQL,
PostgreSQL, SQL Server…

76 1/6/2012

 How does Ajax work?

77 1/6/2012

 Ajax talks with sever:
 Create an instance of the XMLHttpRequest object.
var newXHR = new XMLHttpRequest();
 Use the XHR’s open() method to specify what kind of
data you’ll send and where the data will go
newXHR.open('GET', 'shop.php?productID=34');
 Create a function to handle the results: use callback
function
 Send the request
newXHR.send('q=javascript');
 Receive the response

78 1/6/2012

 Ajax – the jQuery way:

79 1/6/2012

 Ajax – the jQuery way:
 Use .load() function:

 Use: get HTML from a web server and inject it into a page.
 Notes: Just use root-relative links, or make sure the file you load is
located in the same directory as the page that’s using the load()
function.
 Use .get() and .post() function:

 When you get(): when you want to get information, like requesting
the price of a particular product or obtaining a list of most popular
products.
 When use post(): when sending data that will change information
on the server, like a request to delete a file, update a database, or
80 insert new information into a database. 1/6/2012

 Query String:
 Notes: have to escape and encode query string, like:

 Object Literal:

 jQuery Serialize function(): collects all of the field names and the
values currently in each field and creates a single query string.

 Processing data from Server:

 Handling Error:
81 1/6/2012


data could be plain
text, HTML, XML,
or JSON

82 1/6/2012

JSON
 Stands for JavaScript Object Notation
 is usually better than XML;
 JSON is JavaScript, it works quickly and easily in
JavaScript program.

 getJSON() function:

83 1/6/2012

JSON (cont.)
 Access JSON Data:
 Simple data:

 Complex data:

84 1/6/2012

JSONP
 b/c Ajax requests are limited to the same domain.
 stands for JSON with padding. provides one way to
retrieve information from another site.
 Ajax request of the foreign site, you load a script that
contains the JSON code in it. Or linking to an external
JavaScript file on Google.
 For example:

85 1/6/2012

Tips and tricks
 Useful tips:
 $() Is the Same as jQuery()
like
 Saving selections into variables

 Or use chaining:

 Instead of :

 Putting reference in variable:

86 1/6/2012

Tips and tricks (cont.)
 Adding contents few times as possible

NOT

 Use:

 Optimize your selector:
 Use ID selectors if at all possible.
 Use IDs first, as part of a descendent selector.
 Use find function:

87 1/6/2012

Tips and tricks (cont.)
 Using the jQuery docs efficiently:
http://docs.jquery.com/ (especially the jQuery API)
 Compress your JavaScript and other file before deploy
your website:
http://developer.yahoo.com/yui/compressor
 Use firebug – Firefox plugin debugger efficiently
http://www.youtube.com/watch?v=1rfiPaWz4No
 jQuery plugin site: http://plugins.jquery.com/
 jQuery UI site: http://jqueryui.com

88 1/6/2012

Conclusion
 JavaScript is great, but it is also
difficult for you to conquer, you
should use jQuery instead!
 jQuery isn’t only about simpler code and being more
productive.
 It is also about great community, support, tutorials,
plugins, open (free) license, test coverage books,
speed, light weight code
 Keep the jQuery cheat sheet beside you when working
with jQuery
 Practice the tutorial in main reference book!
89 1/6/2012

References
 JavaScript and jQuery the missing manual, 2nd Edition
2011- David Sawyer McFarland
 JavaScript 1.6 Visual Cheat Sheet

Suggest Reading
 jQuery in Actions by Bear Bibeault and Yehuda Katz
 Head First JavaScript by Michael Morrison (O’Reilly)

90 1/6/2012

Thanks for your watching!

Editor: Nguyễn Đức Minh Khôi
Email: nguyenducminhkhoi@gmail.com

Training javascript 2012 hcmut

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