controller-ajax). $kebab_suffix = strtolower( implode( '-', array_merge( array( $dir ), $parts_lc ) ) ); // Build a sub-directory path from any parts after the first (e.g. model/abstract/...). $subdirs = ''; if ( count( $parts_lc ) > 0 ) { $subdirs = '/' . implode( '/', $parts_lc ); } // Also build an underscored basename for legacy filenames. $underscored_basename = strtolower( implode( '_', array_merge( array( $dir ), $parts_lc ) ) ); $candidates = array( // New WPCS-style filename with plugin prefix in the directory root. $includes_dir . '/' . $dir . '/class-bbpress-notify-nospam-' . $kebab_suffix . '.php', // New WPCS-style filename without plugin prefix in the directory root. $includes_dir . '/' . $dir . '/class-' . $kebab_suffix . '.php', // New WPCS-style filename with plugin prefix in correct subdir. $includes_dir . '/' . $dir . $subdirs . '/class-bbpress-notify-nospam-' . $kebab_suffix . '.php', // New WPCS-style filename without plugin prefix (older class-.php style). $includes_dir . '/' . $dir . $subdirs . '/class-' . $kebab_suffix . '.php', // Possible class file in top-level includes with plugin prefix. $includes_dir . '/class-bbpress-notify-nospam-' . $kebab_suffix . '.php', // Possible class file in top-level includes without plugin prefix. $includes_dir . '/class-' . $kebab_suffix . '.php', // Legacy filenames (underscored) inside dir/subdirs. $includes_dir . '/' . $dir . $subdirs . '/' . $underscored_basename . '.class.php', $includes_dir . '/' . $dir . $subdirs . '/' . $underscored_basename . '.php', ); } foreach ( $candidates as $file ) { if ( empty( $file ) ) { continue; } if ( file_exists( $file ) ) { require_once $file; return; } } // Nothing found. Do nothing and let the caller handle the missing class. } );