How can I exclude directories using RecursiveDirectoryIterator - php

Question

I have the function below. Which goes through directories and recursively searches through them to grab a random image file and then attaches that to a post. What I want to do is exclude some files from the search.
I have a comma separated list which I explode into an array, I tried using a filter but couldn't get this to work.
Current function without filter is
function swmc_get_imgs($start_dir, $ext, $exclude=array()){
$dir = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($start_dir));
$files = array();
// Force array of extensions and make them all lower-case
if ( ! is_array($ext))
{
$ext = (array) $ext;
}
$ext = array_unique(array_map('strtolower', $ext));
foreach($dir as $file)
{
// Skip anything that isn't a file
if ( ! $file->isFile())
continue;
// If the file has one of our desired extensions, add it to files array
if (in_array(strtolower(pathinfo($file->getFilename(), PATHINFO_EXTENSION)), $ext)) {
$files[] = $file->getPathname();
}
}
return $files;
}
So the above works but can be fairly expensive still especially with a lot of directories, as such I want to exclude a list of directories stored in a comma list.
I tried the following
class SwmcOnlyFilter extends RecursiveFilterIterator {
public function accept() {
// Accept the current item if we can recurse into it
// or it is a value starting with "test"
return $this->hasChildren() || !in_array($this->current(), explode(",",get_option('swmc_image_excl')));
}
}
And then changing the first part of the swmc_get_imgs function to
$dirIterator = new RecursiveDirectoryIterator($start_dir);
$filter = new SwmcOnlyFilter($dirIterator);
$dir = new RecursiveIteratorIterator($filter);
However the filter doesn't jump over that directory but instead goes into it.
The directories could look like
/uploads/2009/1/2011_pic.jpg
/uploads/2011/1/john_smith.jpg
and so on.
So I may want to exclude 2011 as a directory but not exclude the image that lives in 2009 with 2011 in its title.
CLARIFICATION:
I could filter out these manually by skipping them in the foreach loop, however this still checks them and wastes memory and time. I would prefer to skip these at the time of the grab if possible.

Answer 1

figured it out using the following
function swmc_iterate_imgs($start_dir) {
$directory = $start_dir;
$excludedDirs = explode(",",get_option('swmc_image_excl')); // array of subdirectory paths, relative to $directory, to exclude from search
$it = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($directory));
$fileArr = array(); // numerically indexed array with your files
$x = -1;
while ($it->valid())
{
if (!$it->isDot() && !in_array($it->getSubPath(), $excludedDirs) && preg_match('/(\.(jpg|jpeg|gif|png))$/i', $it->key()) == 1)
{
$fileArr[] = $it->key();
}
$it->next();
}
return $fileArr;
}