Develop web application with PHP

• History of PHP – Created by Rasmus Lerdorf in 1995 for tracking access to his resume – Originally a set of Perl scripts known as the “Personal Home Page” tools – Rewritten in C with

– A language that combines elements of

Perl, C, and Java

• History of PHP

– Created by Rasmus Lerdorf in 1995 for

tracking access to his resume

– Originally a set of Perl scripts known as the

“Personal Home Page” tools

– Rewritten in C with database functionality – Added a forms interpreter and released as PHP/FI: includes Perl-like variables, and

• History of PHP (cont.)

– Rewritten again in and released as version 2.0

in November of 1997

– Estimated user base in 1997 is several

thousand users and 50,000 web sites served – Rewritten again in late 1997 by Andi Gutmans and Zeev Suraski

– More functionality added, database support, protocols and APIs

• History of PHP (cont.)

– Rewritten again in 1997 by Andi Gutmans and Zeev Suraski

– More functionality added (OOP features),

database support, protocols and APIs

– PHP 3.0 is released in June 1998 with some

OO capability

– The core is rewritten in 1998 for improved

• History of PHP (cont.)

– The core is rewritten in 1998 by Zeev and Andi and dubbed the “Zend Engine”

– The engine is introduced in mid 1999 and

is released with version 4.0 in May of 2000 – The estimated user base is hundreds of thousands of developers and several

million of web sites served

• Netcraft Statistics

– 11,869,645 Domains, 1,316,288 IP Addresses

• Performance*

– Zdnet Statistics

• PHP pumped out about 47 pages/second

• Microsoft ASP pumped out about 43 pages/second

• Allaire ColdFusion pumped out about 29

pages/second

• Sun Java JSP pumped out about 13 pages/second

* From PHP HOWTO, July 2001

PHP Language Basics

• The Script Tags

– All PHP code is contained in one of several script tags:

• <?

// Some code

?>

• <?php // Some code here

?>

PHP Language Basics

• Hello World!: An Example

– Like Perl, there is more than one way to do it

• <?php echo “Hello World!”; ?>

• <?php $greeting = “Hello World!”

printf(“%s”, $greeting);

php?>

• define(“COMPANY”, “Acme Enterprises”);

• define(“YELLOW”, “#FFFF00”);

• define(“PI”, 3.14);

PHP Language Basics

• Constants, Data Types and Variables

– Data types

• Integers, doubles and strings

– isValid = true; // Boolean– 25 // Integer– 3.14 // Double– ‘Four’ // String– “Total value” // Another string

echo $arr["somearray"][6]; // 5 echo $arr["somearray"][13]; // 9 echo $arr["somearray"]["a"]; // 42

Built-in Functions

• What comes In the box?

– Array Manipulator Functions

• sort, merge, push, pop, slice, splice, keys, count

– CCVS: Interface to Red Hat’s credit system – COM functions: Interface to Windows COM objects

– Date and Time Functions

• getdate, mkdate, date, gettimeofday, localtime,

Built-in Functions

• What comes In the box?

– Directory Functions

• Platform independent

– Error Handling Functions

• Recover from warnings and errors

– Filesystem Functions

• Access flat files

• Check directory, link, and file status information

Built-in Functions

– Database Functions (cont.)

Built-in Functions

– POSIX Functions

• Manipulate process information

– Regular Expression Functions

• Uses POSIX regex

– Semaphore and Socket Functions

• Available only on Unix

– Session Management Functions

$ConfigFile = "$ConfigPath/paperwork.conf";

$CountryList = "$DataPath/countries.txt";

$StateAbbrList = "$DataPath/usstateabbrs.txt";

Tricks and Tips

• Coding

– Prototype your web pages first

• Separate the design of the site from the coding

– Turn repetitive code into functions

• Makes for more maintainable and reusable code

– Turn grunt code into functions

• Database access, configuration file access

Tricks and Tips

Tricks and Tips

Tricks and Tips

• Development Tools

– Color coding editors

• vim, Emacs, Visual SlickEdit

– IDEs

• Windows

– Macromedia Dreamweaver – Allaire Homesite

– Zend’s PHPEdit

• Linux

• Private, protected and abstract functions

• Private, protected and constant variables

• Namespaces

– Newsgroups

• comp.lang.php