Custom Loop Shortcode for displaying a GPP Content Template

custom-loop-shortcode-gpp.php

<?php
function db_custom_loop_shortcode($atts, $content = null) {
    global $post;
    // Set query args
    $args = array(
        'post_type' => 'post',
        'posts_per_page' => '3',
        'post__not_in' => array( $post->ID ), // don't display current post
    );
    // Optional arguments for setting category term relationship on single post
    if ( is_single() && has_category() ) {  
        $category = get_the_category($post->ID);
        $category_id = $category[0]->cat_ID;
        $category_count = $category[0]->count;
        if ( $category_count > 1 ) {
            $args['category__in'] = array($category_id);
        }
    } 
    $latest = new WP_Query($args);
    // Output loop
    if ( $latest->have_posts() ) {
        ob_start();
        echo '<div class="gb-grid-wrapper gb-grid-wrapper-global">';     
        while ($latest->have_posts()) : $latest->the_post();
            echo '<div class="gb-grid-column gb-grid-column-global-33">';
            do_action('db_custom_post_loop'); // Hook name for content template
            echo '</div>';
        endwhile;
        echo '</div>';
        wp_reset_postdata();
        return ob_get_clean();
    }
}
add_shortcode('db_display_custom_post_loop', 'db_custom_loop_shortcode');