How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?

The 100% working solution

public static function rmdir_recursive($directory, $delete_parent = null)
  {
    $files = glob($directory . '/{,.}[!.,!..]*',GLOB_MARK|GLOB_BRACE);
    foreach ($files as $file) {
      if (is_dir($file)) {
        self::rmdir_recursive($file, 1);
      } else {
        unlink($file);
      }
    }
    if ($delete_parent) {
      rmdir($directory);
    }
  }

It seems that all other answers assume the path given to the function is always a directory. This variant works to remove directories as well as single files:

/**
 * Recursively delete a file or directory.  Use with care!
 *
 * @param string $path
 */
function recursiveRemove(string $path) {
    if (is_dir($path)) {
        foreach (scandir($path) as $entry) {
            if (!in_array($entry, ['.', '..'], true)) {
                recursiveRemove($path . DIRECTORY_SEPARATOR . $entry);
            }
        }
        rmdir($path);
    } else {
        unlink($path);
    }
}

EDIT: If you're picky (and you should be picky) you may want to add code to check for scandir(), rmdir() and unlink() returning an error and throw an exception if so.

Using DirectoryIterator and recursion correctly:

function deleteFilesThenSelf($folder) {
    foreach(new DirectoryIterator($folder) as $f) {
        if($f->isDot()) continue; // skip . and ..
        if ($f->isFile()) {
            unlink($f->getPathname());
        } else if($f->isDir()) {
            deleteFilesThenSelf($f->getPathname());
        }
    }
    rmdir($folder);
}