gistfile1.php

        <?php
            if (perch_get('s')) {
                $post = array(
                    'filter' => 'slug',
                    'sort-order' => 'DESC',
                    'count' => 1,
                    'template' => 'blog/listing.html'
                );
            } else {
                $post = array(
                    'sort' => 'postDateTime',
                    'sort-order' => 'DESC',
                    'count' => 1,
                    'template' => 'blog/listing.html'
                ); 
            }

            perch_blog_custom($post);
        ?>