Why are some of my thumbnails not being generated?

I am currently developing my new theme over at testing.detailsofmylife.net and I am using a WooThemes template as my basic design.

I want to try and include their WooTabs widget as graphically I think it is quite appealing for displaying post data to visitors. I know a lot of you aren’t fond of TimThumb but it is the script that the theme uses to generate thumbnails so I need to try and get it working so the layout can finally work perfectly.

As you can see from the widget on my site, two of the thumbnails have not been generated by the TimThumb function, but I cannot fully understand why.

For example, a working thumbnail url looks like this in the widget:

http://testing.detailsofmylife.net/wp-content/themes/headlines/thumb.php?src=http://testing.detailsofmylife.net/wp-content/uploads/2010/09/Claire-Maguire-Aint-Nobody-Breakage-Remix.jpg&w=50&h=50&zc=1&q=90

but a broken thumbnail url looks like this:

http://testing.detailsofmylife.net/wp-content/themes/headlines/thumb.php?src=http://media.detailsofmylife.net/uploads/2010/04/flux+pavilion.jpg&w=50&h=50&zc=1&q=90

The problem occurs I think due to the location of the media, but I have added both domains to the list of external domains that are allowed to work with the script.

And if you check the image urls by themselves (working v.s. not working) then you can see that they are both working correctly by themselves. Surely then they should both operate within the script?

Any help would be much appreciated as it is driving me slightly mental.

A copy of my code for TimThumb is available at the end of the post. If you need any other data/information let me know 🙂

<?php
/**
 * TimThumb script created by Ben Gillbanks, originally created by Tim McDaniels and Darren Hoyt
 * http://code.google.com/p/timthumb/
 * 
 * GNU General Public License, version 2
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 *
 * Examples and documentation available on the project homepage
 * http://www.binarymoon.co.uk/projects/timthumb/
 */

define ('CACHE_SIZE', 1000);                // number of files to store before clearing cache
define ('CACHE_CLEAR', 20);                 // maximum number of files to delete on each cache clear
define ('CACHE_USE', TRUE);                 // use the cache files? (mostly for testing)
define ('CACHE_MAX_AGE', 864000);           // time to cache in the browser
define ('VERSION', '1.26');                 // version number (to force a cache refresh)
define ('DIRECTORY_CACHE', './cache');      // cache directory
define ('MAX_WIDTH', 1500);                 // maximum image width
define ('MAX_HEIGHT', 1500);                // maximum image height
define ('ALLOW_EXTERNAL', FALSE);           // allow external website (override security precaution - not advised!)
define ('MEMORY_LIMIT', '30M');             // set PHP memory limit
define ('MAX_FILE_SIZE', 1500000);          // file size limit to prevent possible DOS attacks (roughly 1.5 megabytes)
define ('CURL_TIMEOUT', 10);                // timeout duration. Tweak as you require (lower = better)

// external domains that are allowed to be displayed on your website
$allowedSites = array (
    'photobucket.com',
    'detailsofmylife.net',
    'testing.detailsofmylife.net',
    'detailsofmylife.net',
    'img.youtube.com',
    'media.detailsofmylife.net',
);

// STOP MODIFYING HERE!
// --------------------

// sort out image source
$src = get_request ('src', '');
if ($src == '' || strlen ($src) <= 3) {
    display_error ('no image specified');
}

// clean params before use
$src = clean_source ($src);

// get mime type of src
$mime_type = mime_type ($src);

// used for external websites only
$external_data_string = '';

// generic file handle for reading and writing to files
$fh = '';

// check to see if this image is in the cache already
// if already cached then display the image and die
check_cache ($mime_type);

// cache doesn't exist and then process everything
// check to see if GD function exist
if (!function_exists ('imagecreatetruecolor')) {
    display_error ('GD Library Error: imagecreatetruecolor does not exist - please contact your webhost and ask them to install the GD library');
}

if (function_exists ('imagefilter') && defined ('IMG_FILTER_NEGATE')) {
    $imageFilters = array (
        1 => array (IMG_FILTER_NEGATE, 0),
        2 => array (IMG_FILTER_GRAYSCALE, 0),
        3 => array (IMG_FILTER_BRIGHTNESS, 1),
        4 => array (IMG_FILTER_CONTRAST, 1),
        5 => array (IMG_FILTER_COLORIZE, 4),
        6 => array (IMG_FILTER_EDGEDETECT, 0),
        7 => array (IMG_FILTER_EMBOSS, 0),
        8 => array (IMG_FILTER_GAUSSIAN_BLUR, 0),
        9 => array (IMG_FILTER_SELECTIVE_BLUR, 0),
        10 => array (IMG_FILTER_MEAN_REMOVAL, 0),
        11 => array (IMG_FILTER_SMOOTH, 0),
    );
}

// get standard input properties
$new_width =  (int) abs (get_request ('w', 0));
$new_height = (int) abs (get_request ('h', 0));
$zoom_crop = (int) get_request ('zc', 0);
$quality = (int) abs (get_request ('q', 75));
$align = get_request ('a', 'c');
$filters = get_request ('f', '');
$sharpen = (bool) get_request ('s', 0);

// set default width and height if neither are set already
if ($new_width == 0 && $new_height == 0) {
    $new_width = 100;
    $new_height = 100;
}

// ensure size limits can not be abused
$new_width = min ($new_width, MAX_WIDTH);
$new_height = min ($new_height, MAX_HEIGHT);

// set memory limit to be able to have enough space to resize larger images
ini_set ('memory_limit', MEMORY_LIMIT);

if (file_exists ($src)) {

    // open the existing image
    $image = open_image ($mime_type, $src);
    if ($image === false) {
        display_error ('Unable to open image : ' . $src);
    }

    // Get original width and height
    $width = imagesx ($image);
    $height = imagesy ($image);
    $origin_x = 0;
    $origin_y = 0;

    // generate new w/h if not provided
    if ($new_width && !$new_height) {
        $new_height = floor ($height * ($new_width / $width));
    } else if ($new_height && !$new_width) {
        $new_width = floor ($width * ($new_height / $height));
    }

    // scale down and add borders
    if ($zoom_crop == 3) {

        $final_height = $height * ($new_width / $width);

        if ($final_height > $new_height) {
            $new_width = $width * ($new_height / $height);
        } else {
            $new_height = $final_height;
        }

    }

    // create a new true color image
    $canvas = imagecreatetruecolor ($new_width, $new_height);
    imagealphablending ($canvas, false);

    // Create a new transparent color for image
    $color = imagecolorallocatealpha ($canvas, 0, 0, 0, 127);

    // Completely fill the background of the new image with allocated color.
    imagefill ($canvas, 0, 0, $color);

    // scale down and add borders
    if ($zoom_crop == 2) {

        $final_height = $height * ($new_width / $width);

        if ($final_height > $new_height) {

            $origin_x = $new_width / 2;
            $new_width = $width * ($new_height / $height);
            $origin_x = round ($origin_x - ($new_width / 2));

        } else {

            $origin_y = $new_height / 2;
            $new_height = $final_height;
            $origin_y = round ($origin_y - ($new_height / 2));

        }

    }

    // Restore transparency blending
    imagesavealpha ($canvas, true);

    if ($zoom_crop > 0) {

        $src_x = $src_y = 0;
        $src_w = $width;
        $src_h = $height;

        $cmp_x = $width / $new_width;
        $cmp_y = $height / $new_height;

        // calculate x or y coordinate and width or height of source
        if ($cmp_x > $cmp_y) {

            $src_w = round ($width / $cmp_x * $cmp_y);
            $src_x = round (($width - ($width / $cmp_x * $cmp_y)) / 2);

        } else if ($cmp_y > $cmp_x) {

            $src_h = round ($height / $cmp_y * $cmp_x);
            $src_y = round (($height - ($height / $cmp_y * $cmp_x)) / 2);

        }

        // positional cropping!
        switch ($align) {
            case 't':
            case 'tl':
            case 'lt':
            case 'tr':
            case 'rt':
                $src_y = 0;
                break;

            case 'b':
            case 'bl':
            case 'lb':
            case 'br':
            case 'rb':
                $src_y = $height - $src_h;
                break;

            case 'l':
            case 'tl':
            case 'lt':
            case 'bl':
            case 'lb':
                $src_x = 0;
                break;

            case 'r':
            case 'tr':
            case 'rt':
            case 'br':
            case 'rb':
                $src_x = $width - $new_width;
                $src_x = $width - $src_w;
                break;

            default:
                break;
        }

        imagecopyresampled ($canvas, $image, $origin_x, $origin_y, $src_x, $src_y, $new_width, $new_height, $src_w, $src_h);

    } else {

        // copy and resize part of an image with resampling
        imagecopyresampled ($canvas, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

    }

    if ($filters != '' && function_exists ('imagefilter') && defined ('IMG_FILTER_NEGATE')) {
        // apply filters to image
        $filterList = explode ('|', $filters);
        foreach ($filterList as $fl) {

            $filterSettings = explode (',', $fl);
            if (isset ($imageFilters[$filterSettings[0]])) {

                for ($i = 0; $i < 4; $i ++) {
                    if (!isset ($filterSettings[$i])) {
                        $filterSettings[$i] = null;
                    } else {
                        $filterSettings[$i] = (int) $filterSettings[$i];
                    }
                }

                switch ($imageFilters[$filterSettings[0]][1]) {

                    case 1:

                        imagefilter ($canvas, $imageFilters[$filterSettings[0]][0], $filterSettings[1]);
                        break;

                    case 2:

                        imagefilter ($canvas, $imageFilters[$filterSettings[0]][0], $filterSettings[1], $filterSettings[2]);
                        break;

                    case 3:

                        imagefilter ($canvas, $imageFilters[$filterSettings[0]][0], $filterSettings[1], $filterSettings[2], $filterSettings[3]);
                        break;

                    case 4:

                        imagefilter ($canvas, $imageFilters[$filterSettings[0]][0], $filterSettings[1], $filterSettings[2], $filterSettings[3], $filterSettings[4]);
                        break;

                    default:

                        imagefilter ($canvas, $imageFilters[$filterSettings[0]][0]);
                        break;

                }
            }
        }
    }

    // sharpen image
    if ($sharpen && function_exists ('imageconvolution')) {

        $sharpenMatrix = array (
            array (-1,-1,-1),
            array (-1,16,-1),
            array (-1,-1,-1),
        );

        $divisor = 8;
        $offset = 0;

        imageconvolution ($canvas, $sharpenMatrix, $divisor, $offset);

    }

    // output image to browser based on mime type
    show_image ($mime_type, $canvas);

    // remove image from memory
    imagedestroy ($canvas);

    // if not in cache then clear some space and generate a new file
    clean_cache ();

    die ();

} else {

    if (strlen ($src)) {
        display_error ('image ' . $src . ' not found');
    } else {
        display_error ('no source specified');
    }

}


/**
 *
 * @global <type> $quality
 * @param <type> $mime_type
 * @param <type> $image_resized 
 */
function show_image ($mime_type, $image_resized) {

    global $quality;

    $cache_file = get_cache_file ($mime_type);

    if (strpos ($mime_type, 'jpeg') > 1) {
        imagejpeg ($image_resized, $cache_file, $quality);
    } else {
        imagepng ($image_resized, $cache_file, floor ($quality * 0.09));
    }

    show_cache_file ($mime_type);

}


/**
 *
 * @param <type> $property
 * @param <type> $default
 * @return <type> 
 */
function get_request ($property, $default = 0) {

    if (isset ($_GET[$property])) {
        return $_GET[$property];
    } else {
        return $default;
    }

}


/**
 *
 * @param <type> $mime_type
 * @param <type> $src
 * @return <type>
 */
function open_image ($mime_type, $src) {

    if (strpos ($mime_type, 'jpeg') !== false) {
        $image = imagecreatefromjpeg ($src);
    } elseif (strpos ($mime_type, 'png') !== false) {
        $image = imagecreatefrompng ($src);
    } elseif (strpos ($mime_type, 'gif') !== false) {
        $image = imagecreatefromgif ($src);
    }

    return $image;

}

/**
 * clean out old files from the cache
 * you can change the number of files to store and to delete per loop in the defines at the top of the code
 *
 * @return <type>
 */
function clean_cache () {

    // add an escape
    // Reduces the amount of cache clearing to save some processor speed
    if (rand (1, 50) > 10) {
        return true;
    }

    flush ();

    $files = glob (DIRECTORY_CACHE . '/*', GLOB_BRACE);

    if (count ($files) > CACHE_SIZE) {

        $yesterday = time () - (24 * 60 * 60);

        usort ($files, 'filemtime_compare');
        $i = 0;

        foreach ($files as $file) {

            $i ++;

            if ($i >= CACHE_CLEAR) {
                return;
            }

            if (@filemtime ($file) > $yesterday) {
                return;
            }

            if (file_exists ($file)) {
                unlink ($file);
            }

        }

    }

}


/**
 * compare the file time of two files
 *
 * @param <type> $a
 * @param <type> $b
 * @return <type>
 */
function filemtime_compare ($a, $b) {

    $break = explode ('/', $_SERVER['SCRIPT_FILENAME']);
    $filename = $break[count ($break) - 1];
    $filepath = str_replace ($filename, '', $_SERVER['SCRIPT_FILENAME']);

    $file_a = realpath ($filepath . $a);
    $file_b = realpath ($filepath . $b);

    return filemtime ($file_a) - filemtime ($file_b);

}


/**
 * determine the file mime type
 *
 * @param <type> $file
 * @return <type>
 */
function mime_type ($file) {

    $file_infos = getimagesize ($file);
    $mime_type = $file_infos['mime'];

    // no mime type
    if (empty ($mime_type)) {
        display_error ('no mime type specified');
    }

    // use mime_type to determine mime type
    if (!preg_match ("/jpg|jpeg|gif|png/i", $mime_type)) {
        display_error ('Invalid src mime type: ' . $mime_type);
    }

    return strtolower ($mime_type);

}


/**
 *
 * @param <type> $mime_type
 */
function check_cache ($mime_type) {

    if (CACHE_USE) {

        if (!show_cache_file ($mime_type)) {
            // make sure cache dir exists
            if (!file_exists (DIRECTORY_CACHE)) {
                // give 777 permissions so that developer can overwrite
                // files created by web server user
                mkdir (DIRECTORY_CACHE);
                chmod (DIRECTORY_CACHE, 0777);
            }
        }

    }

}


/**
 *
 * @param <type> $mime_type
 * @return <type> 
 */
function show_cache_file ($mime_type) {

    // use browser cache if available to speed up page load
    if (isset ($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
        if (strtotime ($_SERVER['HTTP_IF_MODIFIED_SINCE']) < strtotime('now')) {
            header ('HTTP/1.1 304 Not Modified');
            die ();
        }
    }

    $cache_file = get_cache_file ($mime_type);

    if (file_exists ($cache_file)) {

        // change the modified headers
        $gmdate_expires = gmdate ('D, d M Y H:i:s', strtotime ('now +10 days')) . ' GMT';
        $gmdate_modified = gmdate ('D, d M Y H:i:s') . ' GMT';

        // send content headers then display image
        header ('Content-Type: ' . $mime_type);
        header ('Accept-Ranges: bytes');
        header ('Last-Modified: ' . $gmdate_modified);
        header ('Content-Length: ' . filesize ($cache_file));
        header ('Cache-Control: max-age=' . CACHE_MAX_AGE . ', must-revalidate');
        header ('Expires: ' . $gmdate_expires);

        if (!@readfile ($cache_file)) {
            $content = file_get_contents ($cache_file);
            if ($content != FALSE) {
                echo $content;
            } else {
                display_error ('cache file could not be loaded');
            }
        }

        die ();

    }

    return FALSE;

}


/**
 *
 * @staticvar string $cache_file
 * @param <type> $mime_type
 * @return string
 */
function get_cache_file ($mime_type) {

    static $cache_file;
    global $src;

    $file_type = '.png';

    if (strpos ($mime_type, 'jpeg') > 1) {
        $file_type = '.jpg';
    }

    if (!$cache_file) {
        // filemtime is used to make sure updated files get recached
        $cache_file = DIRECTORY_CACHE . '/' . md5 ($_SERVER ['QUERY_STRING'] . VERSION . filemtime ($src)) . $file_type;
    }

    return $cache_file;

}


/**
 *
 * @param <type> $url
 * @return <type> 
 */
function validate_url ($url) {
    $pattern = "/b(?:(?:https?)://|www.)[-a-z0-9+&@#/%?=~_|!:,.;]*[-a-z0-9+&@#/%=~_|]/i";
    return preg_match ($pattern, $url);
}


/**
 *
 * @global array $allowedSites
 * @param string $src
 * @return string
 */
function check_external ($src) {

    global $allowedSites;

    // work out file details
    $fileDetails = pathinfo ($src);
    $filename = 'external_' . md5 ($src);
    $local_filepath = DIRECTORY_CACHE . '/' . $filename . '.' . strtolower ($fileDetails['extension']);

    // only do this stuff the file doesn't already exist
    if (!file_exists ($local_filepath)) {

        if (strpos (strtolower ($src), 'http://') !== false || strpos (strtolower ($src), 'https://') !== false) {

            if (!validate_url ($src)) {
                display_error ('invalid url');
            }

            $url_info = parse_url ($src);

            // convert youtube video urls
            // need to tidy up the code

            if ($url_info['host'] == 'www.youtube.com' || $url_info['host'] == 'youtube.com') {
                parse_str ($url_info['query']);

                if (isset ($v)) {
                    $src = 'http://img.youtube.com/vi/' . $v . '/0.jpg';
                    $url_info['host'] = 'img.youtube.com';
                }
            }

            // check allowed sites (if required)
            if (ALLOW_EXTERNAL) {

                $isAllowedSite = true;

            } else {

                $isAllowedSite = false;
                foreach ($allowedSites as $site) {
                    if (strpos (strtolower ($url_info['host']), $site) !== false) {
                        $isAllowedSite = true;
                    }
                }

            }

            // if allowed
            if ($isAllowedSite) {

                if (function_exists ('curl_init')) {

                    global $fh;

                    $fh = fopen ($local_filepath, 'w');
                    $ch = curl_init ($src);

                    curl_setopt ($ch, CURLOPT_TIMEOUT, CURL_TIMEOUT);
                    curl_setopt ($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0');
                    curl_setopt ($ch, CURLOPT_URL, $src);
                    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, TRUE);
                    curl_setopt ($ch, CURLOPT_HEADER, 0);
                    curl_setopt ($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
                    curl_setopt ($ch, CURLOPT_FILE, $fh);
                    curl_setopt ($ch, CURLOPT_WRITEFUNCTION, 'curl_write');

                    // error so die
                    if (curl_exec ($ch) === FALSE) {
                        unlink ($local_filepath);
                        touch ($local_filepath);
                        display_error ('error reading file ' . $src . ' from remote host: ' . curl_error ($ch));
                    }

                    curl_close ($ch);
                    fclose ($fh);

                } else {

                    if (!$img = file_get_contents ($src)) {
                        display_error ('remote file for ' . $src . ' can not be accessed. It is likely that the file permissions are restricted');
                    }

                    if (file_put_contents ($local_filepath, $img) == FALSE) {
                        display_error ('error writing temporary file');
                    }

                }

                if (!file_exists ($local_filepath)) {
                    display_error ('local file for ' . $src . ' can not be created');
                }

                $src = $local_filepath;

            } else {

                display_error ('remote host "' . $url_info['host'] . '" not allowed');

            }

        }

    } else {

        $src = $local_filepath;

    }

    return $src;

}


/**
 * callback for curl command to receive external images
 * limit the amount of data downloaded from external servers
 * 
 * @global <type> $data_string
 * @param <type> $handle
 * @param <type> $data
 * @return <type>
 */
function curl_write ($handle, $data) {

    global $external_data_string, $fh;

    fwrite ($fh, $data);
    $external_data_string .= $data;

    if (strlen ($external_data_string) > MAX_FILE_SIZE) {
        return 0;
    } else {
        return strlen ($data);
    }

}


/**
 * tidy up the image source url
 *
 * @param <type> $src
 * @return string
 */
function clean_source ($src) {

    $host = str_replace ('www.', '', $_SERVER['HTTP_HOST']);
    $regex = "/^(http(s|)://)(www.|)" . $host . "//i";

    $src = preg_replace ($regex, '', $src);
    $src = strip_tags ($src);
    $src = check_external ($src);

    // remove slash from start of string
    if (strpos ($src, '/') === 0) {
        $src = substr ($src, -(strlen ($src) - 1));
    }

    // don't allow users the ability to use '../'
    // in order to gain access to files below document root
    $src = preg_replace ("/..+//", "", $src);

    // get path to image on file system
    $src = get_document_root ($src) . '/' . $src;

    if (!is_file ($src)) {
        display_error ('source is not a valid file');
    }

    if (filesize ($src) > MAX_FILE_SIZE) {
        display_error ('source file is too big (filesize > MAX_FILE_SIZE)');
    }

    if (filesize ($src) <= 0) {
        display_error ('source file <= 0 bytes. Possible external file download error (file is too large)');
    }

    return realpath ($src);

}


/**
 *
 * @param <type> $src
 * @return string
 */
function get_document_root ($src) {

    // check for unix servers
    if (file_exists ($_SERVER['DOCUMENT_ROOT'] . '/' . $src)) {
        return $_SERVER['DOCUMENT_ROOT'];
    }

    // check from script filename (to get all directories to timthumb location)
    $parts = array_diff (explode ('/', $_SERVER['SCRIPT_FILENAME']), explode ('/', $_SERVER['DOCUMENT_ROOT']));

    $path = $_SERVER['DOCUMENT_ROOT'];

    foreach ($parts as $part) {
        $path .= '/' . $part;
        if (file_exists ($path . '/' . $src)) {
            return $path;
        }
    }

    // special check for microsoft servers
    if (!isset ($_SERVER['DOCUMENT_ROOT'])) {
        $path = str_replace ("/", "", $_SERVER['ORIG_PATH_INFO']);
        $path = str_replace ($path, '', $_SERVER['SCRIPT_FILENAME']);

        if (file_exists ($path . '/' . $src)) {
            return $path;
        }
    }

    display_error ('file not found');

}


/**
 * generic error message
 *
 * @param <type> $errorString
 */
function display_error ($errorString = '') {

    header ('HTTP/1.1 400 Bad Request');
    echo '<pre>' . htmlentities ($errorString);
    echo '<br />Query String : ' . htmlentities ($_SERVER['QUERY_STRING']);
    echo '<br />TimThumb version : ' . VERSION . '</pre>';
    die ();

}