Featured Article
Latest Post

Thursday, April 11, 2013

jQuery Syntax

Welcome back, after installing jQuery , we are ready to write our magic code, So this tutorial will help you to learn the basic syntax of jQuery which is realy the most important step when learning  any programming language.Unfortunatly , many beginners who wants to learn faster ignore this step and focus on advanced technics and complex functions , but they'll find many big problems because they don't know how this function's built and what does it mean this keyword , ...



Like any other Javascript library , jQuery was simply designed to change and interact the Html document . So , we have to understand the way that javascript could interact with Html , in other words, the DOM (Document Object Model)  .The image below represent a DOM structure for an Html document :

DOM Structure

The DOM define the way to access and manipulate Html Documents , Every node in Html can be easily accessed by Javascript and then jQuery .Don't worry , you will learn more about DOM interaction in the next tutorials .So , let's move to the  jQuery syntax.

Indeed , the process is easy to understand , jQuery access the Html or CSS elemnt using a 'Selector'  and then it perform an action .

A jQuery selector start with this symbol : $( )  ,  Inside the parentheses, we can put :

    -Html Tag name :      $('h1')   to access all the level 1 headers in the Html document.
    -Tag Class : The same way when we refer to a Html tag class in CSS using the point : . at the begin of the class name  . let's consider the following html code :

<p class = 'paragraph'></p>

to access this element using jQuery , simply add the tag class name inside the parentheses and preced it by a point :

$('.paragraph')

      -Tag Id : the same procedure for the class , just replace the point with #

<h1 id='header-1'>this is a header<h1> 

$('#header-1') 


Note : 

If you want to select all the elements in the document , just put this symbol : * inside the parentheses.
example : $('*') 
 


Friday, April 5, 2013

How to install jQuery ?

As you learned in the first tutorial , jQuery is a JavaScript library. In other words, a file extension ". Js". For use in an HTML page, you have to refer to it inside  <script> tag, preferably inside <head> like this  :

Install jQuery

The value of the src attribute is jquery.js. As you can see, the file location is not specified in the attribute. This means that it must be in the same folder as the HTML document. However, If you use the previous instruction ,the jquery Library will not be usable , There are two different solutions :   

1- If your computer is not always connected to the Internet and /or if your Internet connection is not fast, you can download jQuery to any folder and reference it locally.   

 2- If your computer is always connected to the Internet, you can reference the jQuery library, indicating a Web address.  

Let's Examine the two solutions !
 

Download jQuery locally :  

  Step1 : Go to the jQuery Official site and  Click on "Download  jQuery" Button in the Home page.
  Step2 : Choose : "Download the compressed, production jQuery 1.9.1"  , a .txt file that contain the   required code will open.  Copy and paste it into bloc note and save the file with  "jquery.js' as name in the same folder of the Html page.
  Step3 : Copy and paste the code below between <head> and  </head> :
 

All jQuery functions and Coding work must be inside the script tag. So , Now let's move to the second method to install jQuery :

Using CDN :


Using CDN (Content Management Network) , jQuery Installation become easier than downloading the library . In fact , with CDN , jQuery is hosted by Google and Microsoft , you just have to refer to it by adding a special link to your script tag .

jQuery Google CDN URL : ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js
jQuery Microsoft CDN URL : ajax.aspnetcdn.com/ajax/jQuery/jquery-1.9.1.min.js

Note : 
the Links Provided above refers to the 1.9.1 version of jQuery , which is the recent one so far .

So if you want to use the CDN Method then  add one of the below codes  inside the <head> tag .

Google CDN :
 


Microsoft CDN :




 
Now that we installed jQuery , Our web page is able to execute jQuery events and functions correctly , So let's move to the next tutorial.


Thursday, February 7, 2013

What is jQuery ?


You want more for your web pages. You’ve got HTML and CSS_under your belt and want to add scripting to your skill set, but you don’t want to spend your Time  writing lines and lines of script. You need a scripting library that allows you to change webpages on the fly. And since we’re wishing, can it play well with AJAX and PHP, too?
Can it do in 3 lines of code what most client-side languages do in 15?

No way! You need to meet jQuery.


What is jQuery ?

jQuery is a Javascript library, and it is a language designed to simplify the client-side scripts in the browser. It was created by John Resig at BarCamp New York in 2006. It is an open source software under licenses from MIT and GPL combined. Jquery 1.9.1 is the latest version disponible in the jquery official site .
jquery tutorial for beginners
You will find the slogan with the jQuery logo  : “Write less, Do more “.In fact, you can make nice effects with a few lines of jQuery code. Its syntax is very easy to understand.
As a  jQuery beginner ; code once you understand the basic concepts available in the next tutorials. jQuery is particularly suitable for:
         - Create animations.
         - Handle browser  events.
         - Loading Content using AJAX programs.
         - Create Awesome sliders like the one in our Home page.
         - Build professional Mobile phone Applications.
         - …..

It also used in creating web pages and dynamic elements. It allows developers to create plugins that are compatible with a wide number of platforms such us : Adobe Dreamweaver,Wordpress, Joomla...etc.


Thousands of jQuery plugins are available on the web. Among the most common were assistants AJAX data grids, XML tools, drag and drop, the manipulators Cookies, etc.. You can find the best plugins in the jQuery official page.

What makes jQuery so powerful and universal ?

The JavaScript language was born in 1995. Since then, its implementation in different browsers (Safari, Google chrome,Firefox...) on the market has made ​​a rather haphazard way: over the different versions (both language browsers), some features have been retained, others do not. Thus, a single instruction can be recognized JavaScript in a browser and not in another, even in some version of a browser and not in another. What a headache for programmers!
Fortunately, jQuery comes to the rescue: defining its own set of instructions, it acts as a wrapper for
different versions of JavaScript, whether existing or coming. On the other hand, it allows browsers present on market, their multiple versions and their compatibility with the instructions of JavaScript and AJAX.
For a script written in JavaScript to run correctly on different versions of each browser,
programmer-like you-must set up a series of tests and run a specific code for each browser and version ,

as shown in the following figure

Javascript browsers test



With jQuery, these tests are unnecessary: just run the necessary instructions, regardless of the browser used, or version of JavaScript compatible with this browser.        
Where applicable, all these tests are made ​​so transparent . In your case, you only have to worry about the code. 

Remember, jQuery is very convenient, but do not enjoy and think only of the visual development : a page must foremost based on solid HTML bases !

But what happens when a new version of JavaScript born
Well, the jQuery  instructions are completed. Accordingly. You can continue to use the instructions already used and / or consult the documentation available on the new instructions. Whatever your approach, all used instructions work in all available browsers. This approach is a real bonus for you, whether beginner or experienced.
I will add some other details that will certainly convince you that you made ​​the right choice by deciding to learn jQuery
:
                        - The official documentation is available for everyone and in high quality.
                        - The Community that revolves around jQuery is expanding and provides quality support.
                        - Many leading players of the Web (Microsoft, Google, Amazon, Twitter, Mozilla, etc.), Use jQuery.
                       - A multitude of plugins available to enhance the basic capabilities of jQuery.

   
Welcome to the wonderful world of jQuery !

How to Install jQuery
Reviewed by Jack brownon Apr 2 2013
Rating: 5

Popular Posts

From Pinterest

Bloglog