Learning PHP 5

Chapter 13. What Else Can You Do with PHP?

This book covers the fundamental PHP topics that you need for everyday dynamic web site development, such as handling forms, working with a database, and remembering users with sessions. Beyond that core, though, PHP can do much more. Here are a few paragraphs, an example or two, and links to more info about many other capabilities of PHP.

Graphics

Your PHP programs can produce more than just HTML web pages. With the GD extension, they can also dynamically generate graphics—for example, you can create custom buttons. Example 13-1 draws a rudimentary button whose text comes from the button URL variable.

Example 13-1. Drawing a button image

<?php // GD's built-in fonts are numbered from 1 - 5 $font = 3; // Calculate the appropriate image size $image_height = intval(imageFontHeight($font) * 2); $image_width = intval(strlen($_GET['button']) * imageFontWidth($font) * 1.3); // Create the image $image = imageCreate($image_width, $image_height); // Create the colors to use in the image // gray background $back_color = imageColorAllocate($image, 216, 216, 216); // blue text $text_color = imageColorAllocate($image, 0, 0, 255); // black border $rect_color = imageColorAllocate($image, 0, 0, 0); // Figure out where to draw the text // (Centered horizontally and vertically $x = ($image_width - (imageFontWidth($font) * strlen($_GET['button']))) / 2; $y = ($image_height - imageFontHeight($font)) / 2; // Draw the text imageString($image, $font, $x, $y, $_GET['button'], ...