Posted By

Kit on 10/22/09

Tagged

image

Versions (?)

Last Edited at 10/22/09 01:22am

Statistics

Viewed 572 times

Favorited by 1 user(s)

Related snippets

Auto-generate thumbnail in equivalent location (unless one has been manually created)

/ Published in: PHP

Not particularly novel, but quite clean. Allows you to put images in any location on the server and saves having to generate thumbnails at upload time.

The URL to this file should be:

`//`

Valid request types:

* `view` â€” View the image full-size (don't scale)
* `preview` â€” View the image at a medium scale
* `thumb` â€” Show a thumbnail of the image

Images can be JPEGs or PNGs. Broken URLs redirect to a designated 404 image.

Thumbnails and previews will be stored using an identical folder hierarchy inside the `thumbnails` and `previews` folders inside the images folder.

Highlighted TextExpand

<?php

set_error_handler('showBrokenImage');

$imagesFolder = 'images/'; // Change this if required to point to your source folder
	$brokenImage = $imagesFolder.'brokenimage.png';
	$thumbnailHeight = $thumbnailWidth = 80; // Set to the max size of your thumbnail
	$previewHeight = $previewWidth = 250; // Set to the max size of your preview images
	date_default_timezone_set('Australia/NSW'); // Remove or update this line depending on your PHP.ini settings

try {
		if(empty($_SERVER['PATH_INFO']) || strpos($_SERVER['PATH_INFO'], ':') !== false || strpos($_SERVER['PATH_INFO'], '..') !== false) {
			throw new exception('Invalid path');
		}
	
		$pathComponents = explode('/', strtolower(trim((isset($_SERVER['PATH_INFO']) && strlen(trim($_SERVER['PATH_INFO'], '/')) ? $_SERVER['PATH_INFO'] : ''), '/')));
	
		if($pathComponents[0] === 'thumb') {
			$outputWidth = $thumbnailWidth;
			$outputHeight = $thumbnailHeight;
		} else {
			$outputWidth = $previewWidth;
			$outputHeight = $previewHeight;
		}
	
		function mkdir_recursive($pathname, $mode = 0777) {
			is_dir(dirname($pathname)) || mkdir_recursive(dirname($pathname), $mode);
			return is_dir($pathname) || @mkdir($pathname, $mode);
		}
	
		$file = $imagesFolder.trim(substr($_SERVER['PATH_INFO'], strlen('/'.$pathComponents[0])), '/');
		$fileExtension = strtolower(substr($file, strrpos($file, '.') + 1));
		
		if(!is_file($file)) {
			throw new exception('Invalid path');
		}
	
		if(in_array($pathComponents[0], array('thumb', 'preview'))) {
			// Generate a smaller image if we haven't already got one
			$thumbFile = str_replace($imagesFolder, $imagesFolder.($pathComponents[0] === 'thumb' ? 'thumbnails' : 'previews').'/', $file);
			if(!file_exists($thumbFile) && file_exists($file)) {
				// Generate a thumbnail
				switch($fileExtension) {
					case 'jpg':
					case 'jpeg':
						$sourceImage = imagecreatefromjpeg($file);
						break;
					
					case 'png':
						$sourceImage = imagecreatefrompng($file);
						break;
				}
				
				$sourceX = imagesx($sourceImage);
				$sourceY = imagesy($sourceImage);
				if ($sourceX > $sourceY) {
					$destinationWidth = $outputWidth;
					$destinationHeight = $sourceY * ($outputHeight/$sourceX);
				} else if ($sourceX < $sourceY) {
					$destinationWidth = $sourceX * ($outputWidth/$sourceY);
					$destinationHeight = $outputHeight;
				} else if ($sourceX == $sourceY) {
					$destinationWidth = $outputWidth;
					$destinationHeight = $outputHeight;
				}
	
				$outputImage = imagecreatetruecolor($destinationWidth, $destinationHeight);
				imagecopyresampled($outputImage, $sourceImage, 0, 0, 0, 0, $destinationWidth, $destinationHeight, $sourceX, $sourceY);
				
				// Make sure the destination folder path exists
				mkdir_recursive(dirname($thumbFile));
				
				switch($fileExtension) {
					case 'jpg':
					case 'jpeg':
						imagejpeg($outputImage, $thumbFile);
						break;
					
					case 'png':
						imagepng($outputImage, $thumbFile);
						break;
				}
			}
			
			$file = $thumbFile;
		}
	
		if(!file_exists($file)) {
			outputImage($brokenImage);
		}

outputImage($file);
	} catch(exception $ex) {
		outputImage($brokenImage);
	}

function outputImage($file) {
		error_reporting(0);
		$fileExtension = strtolower(substr($file, strrpos($file, '.') + 1));

header('Last-Modified: '.@date('r', filemtime($file)));
		header('Accept-Ranges: bytes');		
		switch($fileExtension) {
			case 'jpg':
			case 'jpeg':
				header('Content-Type: image/jpeg');
				break;
			
			case 'png':
				header('Content-Type: image/png');
				break;
		}
		header('Content-Length: '.filesize($file));
		@ob_clean();
		flush();
		readfile($file);
		exit;
	}

function showBrokenImage($errno, $errstr) {
		global $brokenImage;
	
		if(!in_array($errno, array(0, E_STRICT, E_NOTICE))) {
			outputImage($brokenImage);
		}

return true; // Don't execute PHP internal error handler
	}

Report this snippet Tweet

Comments

Subscribe to comments

Comment:

You need to login to post a comment.