PHP generates JWT

This script generates basic JWT token

<?php
$decode = file_get_contents('php://input');
$arr = json_decode($decode, true);
if ($arr['email'] == 'me@example.com' && $arr['password'] == '123') {
    $key = 'very-secret-value-only-on-server';
    // header
    $h = ["alg" => "HS256", "typ" => "JWT"];
    $h = base64_encode(json_encode($h));
    
    //payload
    $p = ["username" => "username", "role" => "admin"];
    $p = base64_encode(json_encode($p));
    
    // encryption and signing
    $signature = hash_hmac('sha256', "$h.$p", $key, true);
    $signature = base64_encode($signature);

    $token = "$h.$p.$signature";
    echo $token;
}

You should add iat and exp to payload. Debugger for JWT.

Webgrind profiling in WAMP

You can get list of all PHP functions and their arguments that were executed with Webgrind extension. In URL of page put XDEBUGPROFILE=true as shown on video.



You need to setup your php.ini like this

; XDEBUG Extension

zend_extension = "c:/wamp/bin/php/
php5.5.12/zend_ext/
php_xdebug-2.2.5-5.5-vc11-x86_64.dll"
;
[xdebug]
xdebug.remote_enable = 1
xdebug.profiler_enable = 1
xdebug.profiler_enable_trigger = 1
xdebug.profiler_output_name = cachegrind.out.%t.%p
xdebug.profiler_output_dir = "c:/wamp/tmp"
xdebug.show_local_vars=0

Keep in mind that WAMP has two php.ini files. So you need co change the right one.

XDebug in Eclipse

How to debug a PHP script in eclipse like C program in Visual Studio.

PHP Dependancy Injection

This two scripts show Motor class as dependency that is injected in Car class.

<?php
class Motor {
    public function startEngine(){
        echo 'engine has started';
    }
}

class Car {
    public function __construct(Motor $m){
        $m -> startEngine();
    }
}

$a = new Car(new Motor());
?>

and second example

<?php
class Motor {
    public function __construct(){
        echo 'engine has started';
    }
}

class Car {
    public function __construct(){
        $m = new Motor();
    }
}

$a = new Car();
?>

The point is that instancing of dependent class is not done in client but in consumer class. 

Consuming SOAP services

Full web service description is at http://www.webservicex.net/ws/WSDetails.aspx?CATID=12&WSID=64
Yellow highlighted portion is SOAP Web Service URI
Green Highlighted portion is the method name.

One Way Encryption with Crypt Function and Salt

This tutorial shows how to hash passwords with random string as salt using Blowfish algo and PHP's function Crypt.

Most Useful PHP Snippets

Dumping arrays or objects with HTML markup text as member. This prevents creating iFrame and similar tags in your debug output.

OOP Basics

/**
 * Instances CANNOT use private and protected members
 * Children CAN inherit only public and protected members
 */
class MyClass
{
    public $name = 'John';
    protected $username = 'JohnT23';
    private $password = 'secret';

    function printAll()
    {
        echo "From class MyClass:";
        echo $this->name." ";
        echo $this->username." ";
        echo $this->password." ";
    }
}

$obj = new MyClass();
echo "From Instance \$obj:".$obj->name."\n"; //Works
//echo $obj->username; // Fatal Error
//echo $obj->password; // Fatal Error
$obj->printAll();

echo"\n<br>";

class MyClass2 extends MyClass
{
    // We can re-declare/access the public and protected method
    // but not private ones
    function printAll()
    {
        echo "From class MyClass2:";
        echo $this->name." ";
        echo $this->username." ";
        // Children cannot access private member of parent
        // echo $this->password; // Error
    }
}

$obj2 = new MyClass2();
echo "<br>
 From Instance \$obj2:".$obj2->name; // Works
//echo $obj->username; // Fatal Error
//echo $obj->password; // Fatal Error
$obj2->printAll();

Testing File Permission for file upload and database connectivity

On a freshly installed Linux server you need to test file permission and database connectivity.
Here are some scripts that can help you with that:

Two Way Encryption

Two way encryption on PHP works with mcrypt extension enabled.
Here's a simple snippet that uses password and generates different encryption string every time you reload.

<?php
$string = "This is a string to be encrypted";
$key = "This is a key";
// Encryption Algorithm
$alg = MCRYPT_TWO_FISH;
// Create the initialization vector for added security
$iv = mcrypt_create_iv(mcrypt_get_iv_size($alg, MCRYPT_MODE_ECB), MCRYPT_RAND);
// Output original string
print "Original string: $string <p>";
// Encrypt $string
$encrypted_string = mcrypt_encrypt($alg, $key, $string, MCRYPT_MODE_CBC, $iv);
// Convert to hexadecimal and output to browser
print "Encrypted string: ".bin2hex($encrypted_string)."<p>";
$decrypted_string = mcrypt_decrypt($alg, $key, $encrypted_string, MCRYPT_MODE_CBC, $iv);

print "Decrypted string: $decrypted_string";
?>

A short video how code works

Nesting with columns named id and parent_id

Create table mytable :

CREATE TABLE IF NOT EXISTS `mytable` (
  `id` int(11) NOT NULL,
  `parent_id` int(11) NOT NULL,
  `name` varchar(256) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

--
-- Dumping data for table `mytable`
--

INSERT INTO `mytable` (`id`, `parent_id`, `name`) VALUES
(1, 0, 'item 1'),
(2, 1, 'item 2'),
(3, 2, 'item 3');

And then run following script

Execute Linux Commands from Browser

If you need to execute a shell command using browser here's how to do it. To understand this tutorial you need to have advanced level of understanding of Linux and PHP.

PHP debugging with JavaScript Console, Error and Access Log

You can use JavaScript console to output global and other variables from your PHP file. That way you can use JS console to track what is is going on in PHP backed files that are called by $.ajax. Also you should be familiar with PHP's functions utf8_encode and utf8_decode

Raw outuput of JSON string and Base64 encoded JSON string

JSONP Tutorial

This is an advanced tutorial with working example you must know jQuery and JSONP foundations. JSONP bypass browser's "same origin" policy.

Parse JSON generated by PHP

This tutorial shows how to parse a JSON string generated by PHP. Place job.php and index.html in same folder.

Basic APC Tutorial

APC is very powerful caching system for PHP. Here are some basics. First run test_apc.php and if you in 5 seconds click on delete link the key "str" will be deleted from cache. If you click on delete link after 5 second the key "str" will expire from APC caching system.

Custom Redirects in WordPress

Modify WordPress .htaccess file to make redirect from rss_feed to feed

Complex SQL Queries with columns

Advanced MySQL queries with CASE, IF and FIND_IN_SET:

Highlight a portion of string

Highlight portion of word or whole word

Delete row with jQuery and PHP

Do you want to delete a row in HTML and MySQL table with fancy fade out effect? This is the right tutorial for you assuming that you are familiar with basics of jQuery and PHP.
You make an asynchronous call to PHP script called delete.php so end user doesn't leave page when a row is deleted, instead he gets an alert box that confirms that row is deleted and the row gradually disappears.