BTW: always reply to the list unless asked otherwise.
Jason Pruim wrote:
>
you don't know what a class is or how to use one do you?
(correct me if I'm wrong)
the idea of my particular class is that it is used in
the *script* that serves all your resampled images.
something *like* (it an overly simplified example):
image.php (called as /image.php?id=100&width=200&height=160
============= 8< =======================
<?php
$ic = new ImageCache('/path/to/your/cached/images');
$ic->genCacheFileName(array('id', 'width', 'height'), 'jpg', 'foo');
$files = array();
$files[] = '/path/to/your/src/image/that/corresponds/to/id/100.jpg';
if (!$ic->checkCache()) {
/* generate a resampled version of
* the relevant source file
* and save the generated image to the location
* that is returned by $ic->getCacheFilePath()
*/
}
// this code won't even run if ImageCache determines that
// the browser already has an up2date copy of the
// resampled image locally
$ic->showImage();
exit;
>>
>> <?php
>>
>> class ImageCache
>> {
>> var $validTypes = array('png','gif','jpeg');
>>
>> var $cacheFileName;
>> var $cacheFileType;
>> var $cacheDir;
>>
>> var $im;
>>
>
> Would I change $cDir to a real directory or $this->cacheDir to a real
> directory?
>
>> /* you must give a valid 'cache' dir */
>> function ImageCache($cDir)
>> {
>> $this->cacheDir = $cDir;
>> }
>>
>> /* generate a cache file name for the image your are generating
>> * if your generated output image is dependent on the values of
>> one or more request
>> * variables then you should add the names to the $args array e.g.
>> *
>> * your script take width/height parameter:
>> /image.php?width=200&height=160
>> *
>> * $args should be the following array: array('width', 'height');
>> */
>> function genCacheFileName($args = array(), $type = '', $prefix = '')
>> {
>> /* name/val pair delimiter in the string that results in the
>> hash for the cache id */
>> $qHashMark = '%~^*';
>>
>> $qry = array();
>> $args = (array)$args; natsort($args);
>> foreach ($args as $arg) {
>> if (($val = $this->getR( $arg, false )) !== false) {
>> $qry[] = "{$arg}=".str_replace($qHashMark,'',$val);
>> }
>> }
>>
>> $sep = '-:-';
>> $hash = md5($_SERVER['HTTP_HOST'] .$sep.
>> $_SERVER['SCRIPT_NAME'] .$sep. join($qHashMark,$qry));
>>
>> if (!in_array($type, $this->validTypes)) {
>> if ($type == 'jpg') {
>> $type = 'jpeg';
>> } else {
>> $type = 'png';
>> }
>> }
>>
>> $this->cacheFileType = $type;
>>
>> if (!$prefix) {
>> $prefix = 'cacheimg';
>> }
>>
>> return ($this->cacheFileName = "{$prefix}_{$hash}.{$type}");
>> }
>>
>> /* get the fullpath to the location where the cache file is
>> saved/stored */
>> function getCacheFilePath()
>> {
>> return $this->cacheDir . '/' . $this->cacheFileName;
>> }
>>
>> /* Return true if the cache file is younger than the source file(s),
>> * false otherwise.
>> *
>> * if this func returns true you can output the relevant cache file,
>> * if false is returned it's your responsibility to generate the
>> output file
>> * and save it to the location given by $this->getCacheFilePath()
>> *
>> * the (array of) files passed to this function should be complete
>> paths,
>> * not just filesnames.
>> */
>> function checkCache( $files = array() )
>> {
>> $cacheState = true;
>>
>> $cf = $this->getCacheFilePath();
>> $mTime = is_readable($cf) ? filemtime($cf): 0;
>> $lastModified = gmdate("D, d M Y H:i:s ", $mTime)."GMT";
>> $files = (array) $files;
>>
>> if (!count($files) || !$mTime) {
>> $cacheState = false;
>> } else {
>> foreach($files as $file) {
>> if ($mTime < filemtime( $file )) {
>> $cacheState = false;
>> break;
>> }
>> }
>> }
>>
>> if ($cacheState) {
>> $headers = getallheaders();
>> if (isset($headers['If-Modified-Since']) &&
>> ($headers['If-Modified-Since'] == $lastModified)) {
>> /* The UA has the exact same image we have. */
>> header("HTTP/1.1 304 Not Modified");
>> exit;
>> } else {
>> unset($headers);
>> header("Last-Modified: ".$lastModified);
>> return true;
>> }
>> } else {
>> // not cached - or cache invalidated
>> // must cache the (new) data.
>> return false;
>> }
>> }
>>
>> function showImage($type = '', $quality = 100)
>> {
>> header( "Content-type: image/{$this->cacheFileType}" );
>> readfile( $this->getCacheFilePath() );
>> exit;
>> }
>>
>> function getR($v = '', $r = null, $t = null)
>> {
>> if (!empty($v)) { if (isset($_REQUEST[$v]))
>> {$r=!is_null($t)?$t:$_REQUEST[$v];} }
>> return $r;
>> }
>> }
>>
>> ?>
>>
>>>
>>> Would upgrading to PHP 5* be of any help?
>>
>> not specifically in this case, but I would recommended using php5
>> if your starting out and developing new stuff.
>>
>> php4 is not being actively developed (security & bug fixes still occur).
>>
>> it's not wrong to use php4, and many people have no choice, but I
>> recommend
>> trying to stay on top of whats current and given that your not
>> (AFAICT) running
>> any legacy code there is nothing really stopping you.
>
> Okay, I'll look deeper into upgrading before I go much farther with it
> since I want to learn how to do it right from the beginning :)
>>
>>> I've thought about upgrading
>>> but not knowing much about how to run the server from the command
>>> line(Part of what I'm learning) I didn't want to screw anything up.
>>>
>>>
>>
>> test servers are there to be screwed up, kind of. when your learning
>> and trying things
>> out thing break occasionally. ommelettes, breaking eggs, all that jazz.
>>
>>
>
>
> Test servers are a luxury I don't currently have, just a low use
> web/email/file server in my office. I try not to screw it up to much,
> only killed it 3 or 4 times recently.
>
>
> --
> Jason Pruim
> japruim@xxxxxxxxxx
> Production & Technology Manager
> MQC Specialist (2005 certified)
> 3251 132nd Ave
> Holland MI 49424
> 616.399.2355
> www.raoset.com
>
>
> "America will never be destroyed from the outside. If we falter and lose
> our freedoms, it will be because we destroyed ourselves."
> -Abraham Lincoln
>
>
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