Sorabh Jain saurabhj@yahoo-inc.com

IIT-Delhi 9-Aug-2013

Hacks With PHP,

MySQL & JS

Why PHP ?It is a server side scripting language which allows you to :-• Dynamically edit, change or add any content to a

Web page• Respond to user queries or data submitted from

HTML forms• Access any data or databases and return the result

to a browser• Customize a Web page to make it more useful for

individual users• Provide security since your server code cannot be

viewed from a browser• Does not require any special tools. Create a file with

.php extension and your done.

Why JavaScript ?• Client side scripting language which makes

your browser more interactive.• No need to go back to server for form

validation• JavaScript inserted into HTML pages, can be

executed by all modern web browsers. • It makes you static HTML page dynamic which

was not easy with CSS.

Why MySQL ?• Open source data storage RDBMS which is

easy to install and use with any operating system.

• Lot of support and libraries available in scripting languages like php.

What we need to learn?• Enough PHP to handle simple request• How to talk to mysql data store using PHP• How to parse/generate XML/JSON in PHP• Enough JavaScript to make browser

interactive

How it works?

Getting Started• You need a local server with PHP enabled.• XAMPP for windows• MAMP for Mac OSx• Linux has it by default

<?php $school=”IIT-Delhi"; echo "Hello, $school hackers";?>

Create a file hello.php into webserver directory and call it like this http://localhost:80/hello.php

Getting Started

Basic Syntax• PHP blocks start with <?php and end with ?> -• Every line of PHP has to end with a

semicolon ";”• Variables in PHP start with a $• You print out content to the document in PHP

with the echo command.• $school is variable and it can be printed out• You can jump in and out of PHP anywhere in

the document. So if you intersperse PHP with HTML blocks, that is totally fine. For example:

<?php $origin = 'Outer Space'; $planet = 'Earth'; $plan = 9; $sceneryType = "awful";?><h1>Synopsis</h1><p>It was a peaceful time on planet <?php echo $planet;?> and people in the <?php echo $sceneryType;?> scenery were unaware of the diabolic plan <?php echo $plan;?> from <?php echo $origin;?> that will take their senses to the edge of what can be endured.</p>

Mix Match• You can mix and match HTML and PHP

demo1.php

Displaying more complex data

• You can define arrays in PHP using the array() method$lampstack = array('Linux','Apache','MySQL','PHP');

• If you simply want to display a complex datatype like this in PHP for debugging you can use the print_r() command

$lampstack = array('Linux','Apache','MySQL','PHP');print_r($lampstack);

demo2.php

Arrays• Accessing arrays using index

<ul><?php$lampstack = array('Linux','Apache','MySQL','PHP');echo '<li>Operating System:'.$lampstack[0] . '</li>';echo '<li>Server:' . $lampstack[1] . '</li>';echo '<li>Database:' . $lampstack[2] . '</li>';echo '<li>Language:' . $lampstack[3] . '</li>';?></ul>

demo3.php

Arrays• Iterating through arrays

<ul><?php$lampstack = array(’MacOs','Apache','MySQL','PHP');$labels = array('Operating System','Server','Database','Language');$length = sizeof($lampstack);for( $i = 0;$i < $length;$i++ ){ echo '<li>' . $labels[$i] . ':' . $lampstack[$i] . '</li>';}?></ul> sizeof($array) - this will return the size of the array

demo4.php

Associative Arrays• PHP has associative arrays with string keys<ul><?php$lampstack = array( 'Operating System' => 'Linux', 'Server' => 'Apache', 'Database' => 'MySQL', 'Language' => 'PHP');$length = sizeof($lampstack);$keys = array_keys($lampstack);for( $i = 0;$i < $length;$i++ ){ echo '<li>' . $keys[$i] . ':' . $lampstack[$keys[$i]] . '</li>';}?></ul>

demo5.php

Functions

<?phpfunction renderList($array){ if( sizeof($array) > 0 ){ echo '<ul>'; foreach( $array as $key => $item ){ echo '<li>' . $key . ':' . $item . '</li>'; } echo '</ul>'; }}$lampstack = array( 'Operating System' => ’Windows', 'Server' => 'Apache', 'Database' => 'MySQL', 'Language' => 'PHP');renderList($lampstack);?> demo6.php

Interacting with the web - URL parameters

<?php$name = 'Tom';

// if there is no language defined, switch to Englishif( !isset($_GET['language']) ){ $welcome = 'Oh, hello there, ';}if( $_GET['language'] == 'hindi' ){ $welcome = 'Namastae, ';}switch($_GET['font']){ case 'small': $size = 80; break; case 'medium': $size = 100; break; case 'large': $size = 120; break; default: $size = 100; break;}echo '<style>body{font-size:' . $size . '%;}</style>';echo '<h1>'.$welcome.$name.'</h1>';?>

demo7.php

Loading content from the web

<?php // define the URL to load $url = 'http://cricket.yahoo.com/player-profile/Sachin-Tendulkar_2962'; // start cURL $ch = curl_init(); // tell cURL what the URL is curl_setopt($ch, CURLOPT_URL, $url); // tell cURL that you want the data back from that URL curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // run cURL $output = curl_exec($ch); // end the cURL call (this also cleans up memory so it is // important) curl_close($ch); // display the output echo $output;?>

demo8.php

Connecting to MySQL• Simple example to fetch data from DB

Twitter Api Demo• Creating a sample app on twitter developer

network• Giving proper permissions to app and

specifying which url we want to hit from twitter app.

• Writing code to make o-auth call to twitter• Making twitter api calls after successful o-auth

validation.

Sample Codes PHP sample code:- https://github.com/sorabhjain/phpsamplecode

Twitter Api demo code:-https://github.com/sorabhjain/twitterapi

Twitter api docs:- https://dev.twitter.com/docs/api/1.1

Further Referencehttp://www.php.net/

http://developer.yahoo.comhttp://isithackday.com/hackday-toolbox/

http://phpforhacks/index.htmlhttp://hackyourworld.org/