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PHP

Table of Contents

TODO

Conferences

Useful Libraries

Frameworks

  • Various web frameworks - CodeIgnitor, Laravel, CakePHP, Yii

Misc Libraries

Working with PECL/PEAR

  • PECL - extensions coded in C
  • PEAR deals with pure PHP modules.

n.b. In some cases you need to enable an extension in PHP. For this you need the PHP source code with the extension. You can run phpize to prepare the extension for compiling with configure and make.

n.b. You can also use Composer to declare what your project needs.

Install a package

    pear install PHPUnit

Listing packages

    pear list

Listing remote packages (slow)

    pear remote-list

Discover a channel (to add more packages) with:

     sudo pear channel-discover pear.kotowicz.net

Composer

Search for a library:

    composer search slim

Composer.json example

    {
        "require": {
            "slim/slim": "1.0.*"
        }
    }

Begin a project interactively with:

    composer init

Install packges with:

    composer install

Debugging

    var_dump
    print_r

You can enable verbose logging with:

error_reporting(E_ALL);
ini_set('display_errors', 1);

Command Line

Checking the version:

php -v

Run a script:

php -f util.php

Run as you type:

php -r

Syntax check with:

php -l

Look up docs with(n.b. double dash):

php --rf

Starting the built in web-server:

php -S localhost:4000 server.php

PHP Internals (Hackers Guide) - http://www.php.net/manual/en/internals2.php

Zend 1.0 - Core Engine

  • Zend is the core engine itself
  • PHP can eb extended at the external modules, built-in modules and the Zend engine
  • External modules extension is clean, but performance is slow, load modules via dl().
  • Built-in modules are compiled into PHP and carried around with the process. Requires recompilation of PHP
  • Dynamic and built in modules live in php-src/ext
  • Zend ships prefdefine macros
  • Zend functions (V_GETCWD) wrap regular C functions

Zend Framework - web application framework

Overview of the php.ini file

// or # can be used as a single line comment /* as a multiline comment

Configuration and Bootstrapping

Testing PHP

Use PHPFiddle - http://phpfiddle.org/

Boris is also handy (if compiled with pcntl as an extension to PHP.

Logging

Number of ways of doing this:

echo - basic output
print_r - print out an array
var_dump - displays variables and their types

Typing

Type Juggling - http://www.php.net/manual/en/language.types.type-juggling.php

Types are automatically converted.

Can cast variables in the normal way.

Type comparison - http://www.php.net/manual/en/types.comparisons.php

Variables

Global variables are created outside functions.

Can access from inside a function with the global keyword.

global $name;

You can define a local variable as static so it's not deleted after the function complets

static $name = "jon";

Number of types of variables:

  • Strings

  • Integers (Hex, Octal and Decimal)

  • Floating Point Numbers

  • Boolean

  • Objects

  • Arrays

    $things = array("a", "b")

Can have null values for variables.

Set a constant with:

define("DEFAULTNAME", "Jon");

Equality works with the following:

=== // Same value and type
== // Same value
<> // Not equal
!= // Not equal
and // And
or // Or

String Manipulation

  • implode - joins an array into a string using a char
  • explode - splits a string out into an array
  • preg_match(pattern, text, matches) - matches will be filled with results

Superglobals

Also have superglobals - always accessible from anywhere

$GLOBALS
$_SERVER // headers, paths and script locations, e.g. $_SERVER['SERVER_NAME']
$_REQUEST
$_POST
$_GET

Strings

To concatenate a string (weird) use .=

Helper function:

strlen()
strpos()

Conditionals and Loops

if () {
  // a
} elseif () {
  // b
} else {
  // c
}

Also has switch statement.

while, dowhile, for and foreach

Arrays

Basic arrays

Also have associative arrays (which are like maps)

echo count(array("Bob" => 30, "Jane" => 30));

Multidimensional arrays - http://www.w3schools.com/php/php_arrays_multi.asp

sort(cars)
rsort(cars)
ksort(cars) // By key
arsort(cards) // By value

Forms

Regular expressions with

preg_match("//", $name)

Timing

Use microtime:

    microtime();

Output

echo and print statements output things. Echo can be used to output multiple strings.

echo "This", "is a $name";

Print outputs only one thing and returns true

print $name

Recursive Print:

$a = array(1, 2);
print_r($a);

Database

    mysql_real_escape_string

I/O and Files

Reading from as gzipped file and appending to an in-memory textfile:

    $filename = "example.gz";

    $fh = gzopen($filename, 'r');
$content = "";
while (!gzeof($fh)) {
	$line = gzgets($fh);		
	$content .= $line;		
}

Object Oriented PHP

Classes (and methods) can be final.

Simple class can be created with:

    class Person {
    
        var $name='Bob';
    	
        function Person($name="bob") {
            $this->name = $name;
        }
            
        function get_name() {
            return $this>name;
        }
    }
    
    
    $person = new Person('bill');
    echo 'Person name ' . $person->name . '.';

Constructors exist and destructors with:

    __construct
    __destruct

$self is used to reference methods in the same class.

$this is used for variables in the same object.

Access modifiers for public, protected and private exist.

Fields are called properties in PHP.

Constants, static properties are accessed using :: instead of ->

    self::$property

Constants can be declared using const btw...

Static variables can be declared as follows:

    public static $default_name = 'default';

Calling a superclass method, use parent:

    parent.get_name();

Abstract classes can be declared along with abstract protected function methods to use.

Object interfaces are available which define methods a class must implement but not their behaviour.

    interface iTemplate
    {
        public function setVariable($name, $var);
        public function getHtml($template);
    }

Traits are available in PHP which allows you to introduce groups of methods in a class.

    trait Address {
        function getPostcode() { /*1*/ }
        function getStreetName() { /*2*/ }
    }
    
    class Person {
            use Address. HelperFuncs ;
            ...
    }

See - http://www.php.net/manual/en/language.oop5.traits.php

Implement Iterator to allow foreach over objects... (implement rewind, current, key, next)

Magic Methods - http://www.php.net/manual/en/language.oop5.magic.php

Type Hinting - http://www.php.net/manual/en/language.oop5.typehinting.php

Late Static Binding - http://www.php.net/manual/en/language.oop5.late-static-bindings.php

Objects and References - http://www.php.net/manual/en/language.oop5.references.php