Adds a [my_pmpro_series] shortcode to display a specific series post list.

pmproseries_shortcode.php

<?php
/**
 * This recipe creates a [my_pmpro_series] shortcode
 * to display a specific series post list.
 *
 * This shortcode requires that a Series (Post) ID is provided.
 *
 * To obtain the Post ID for a series, from the
 * WordPress dashboard navigate to Series > Series,
 * click on the series name, in the edit page URL
 * the Post ID is querystring post, e.g if URL is
 * https://example.com/wp-admin/post.php?post=42&action=edit
 * the Post ID = 42
 *
 * To display this series using the shortcode assign that value
 * to the "id" attribute, e.g.
 * [my_pmpro_series id="42"]
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

function my_pmpro_series_shortcode( $atts ) {
	// Bail if PMProSeries is not active.
	if ( ! class_exists( 'PMProSeries' ) ) {
		return false;
	}

	// Require that a Series was specified.
	if ( empty( $atts ) ) {
		return false;
	}

	global $post;
	extract(
		shortcode_atts(
			array(
				'id' => $post->ID,
			),
			$atts
		)
	);

	//start output buffering
	ob_start();
	$series = new PMProSeries( $id );
	$series->getPostList( true ); //true echoes post list
	$temp_content = ob_get_contents();
	ob_end_clean();

	return $temp_content;
}
add_shortcode( 'my_pmpro_series', 'my_pmpro_series_shortcode' );