Intro to PHP Introduction to server-side scripts (It’s all good :D) © TAFE NSW

What is PHP?  PHP is a programming language :D  PHP originally began in Germany as an acronym for Personal Home Page  PHP now stands for PHP Hypertext Pre-Processor  PHP is a server-side script used to dynamically produce web pages  Used in Web Applications  A web application is an application that runs over the entire internet (or intranet). It works like a normal application installed on your computer (although slower because it’s communicating over the internet) except that the processing is performed by an external server rather than on your local computer.  Apps run on all different platforms & devices  PHP works in conjunction with HTML, CSS, JavaScript and SQL (Structure Query Language) (C) TAFE NSW

What is a PHP file, and what can PHP do?  PHP files have the file extension:.php  PHP files can contain any or all of the following: Text, HTML, JavaScript & PHP code  PHP scripts are executed on the web server and plain HTML is returned back to the web browser  PHP can generate dynamic page content  PHP can add, delete and modify data in a database  PHP can restrict user access to pages  PHP can collect form data, and encrypt data  PHP can send and receive cookies (nom nom nom)  PHP can create, open, read, write and close files on the server © TAFE NSW

Why PHP?  PHP is free, widely used, open source, cross-platform, cross-server & efficient  There are many server-side scripting technologies available, PHP has several potential competitors: (C) TAFE NSW DeveloperLanguagePlatformCost? MicrosoftActive Server Pages (ASP) C# Visual Basic (VB) Windows,.NetClosed Source ($Monies$) Python Software Foundation PythonWindows, Linux/Unix, Mac OS X, and has been ported to the Java and.NET virtual machines Open Source Rails Core TeamRuby on RailsWindows, Linux/Unix, Mac OS X Open Source

Plain old web communication Web Browser & Web Server Interaction (C) TAFE NSW  Fetching static web pages from the internet (otherwise known as surfing the net), is in very simple terms a conversation over the internet between the web browser on your computer, and the web server on another computer.  The conversation (without server-side scripting) looks something like this:

How does PHP work? Web Browser & Web Server Interaction (C) TAFE NSW  SQL is supported by all databases, and used with many languages, like PHP  The conversation with PHP & MySQL looks something like this:

References & Further Reading (C) TAFE NSW  Sklar, D Learning PHP 5, O’Reilly Media Inc, December 2008, Figures 1.1 & 1.2  Wikipedia Pages: 