<?php spl_autoload_register( function ( $class ) { // project-specific namespace prefix $prefix = 'DeliciousBrains\\WPMDB\\'; // base directory for the namespace prefix $base_dir = __DIR__ . '/'; // does the class use the namespace prefix? $len = strlen( $prefix ); if ( strncmp( $prefix, $class, $len ) !== 0 ) { // no, move to the next registered autoloader return; } // get the relative class name $relative_class = substr( $class, $len ); // replace the namespace prefix with the base directory, replace namespace // separators with directory separators in the relative class name, append // with .php $file = $base_dir . str_replace( '\\', '/', $relative_class ) . '.php'; // if the file exists, require it if ( file_exists( $file ) ) { require $file; } } );