qa-blob.php

<?php
/*
	Question2Answer by Gideon Greenspan and contributors
	http://www.question2answer.org/

	File: qa-include/qa-blob.php
	Description: Response to blob requests, outputting blob from the database


	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	More about this license: http://www.question2answer.org/license.php
*/


//	Ensure no PHP errors are shown in the blob response

	@ini_set('display_errors', 0);

	function qa_blob_db_fail_handler()
	{
		header('HTTP/1.1 500 Internal Server Error');
		qa_exit('error');
	}


//	Load the Q2A base file which sets up a bunch of crucial stuff

	require 'qa-base.php';

	qa_report_process_stage('init_blob');


//	Output the blob in question

	require_once QA_INCLUDE_DIR.'app/blobs.php';

	qa_db_connect('qa_blob_db_fail_handler');

	$blob=qa_read_blob(qa_get('qa_blobid'));

	if (isset($blob)) {
		header('Cache-Control: max-age=2592000, public'); // allows browsers and proxies to cache the blob

		switch ($blob['format']) {
			case 'jpeg':
			case 'jpg':
				header('Content-Type: image/jpeg');
				break;

			case 'gif':
				header('Content-Type: image/gif');
				break;

			case 'png':
				header('Content-Type: image/png');
				break;

			case 'swf':
				header('Content-Type: application/x-shockwave-flash');
				break;

			default:
				$filename=preg_replace('/[^A-Za-z0-9 \\._-]/', '-', $blob['filename']); // for compatibility with HTTP headers and all browsers

				header('Content-Type: application/octet-stream');
				header('Content-Disposition: attachment; filename="'.$filename.'"');
				break;
		}

		echo $blob['content'];

	} else
		header('HTTP/1.0 404 Not Found');


	qa_db_disconnect();


/*
	Omit PHP closing tag to help avoid accidental output
*/