Access denied messages for RSS feeds and Non Member users. Custom message based on the membership level the user _does_ have

pmpro-custom-advanced-messages.php

<?php
/**
 * Plugin Name: Paid Memberships Pro - Custom Advanced Settings Messages
 * Plugin URI: https://eighty20results.com/paid-memberships-pro/do-it-for-me/
 * Description: Per membership level message for the membership/login required
 * Version: 1.0
 * Author: Paid Memberships Pro / Thomas Sjolshagen <thomas@eighty20results.com>
 * Author URI: https://eighty20results.com/thomas-sjolshagen/
 * License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * License: GPLv2 or later
 *
 * Copyright (c) 2017 - Eighty / 20 Results by Wicked Strong Chicks.
 * ALL RIGHTS RESERVED
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Return the membership level specific text for non-members
 *
 * @param string $text
 *
 * @return string
 */
function pca_non_member_text_filter_by_level( $text ) {
	
	global $current_user;
	$user_level = pmpro_getMembershipLevelForUser( $current_user->ID );
	
	if ( isset( $user_level->id ) ) {
		return pca_get_level_messages( 'non_member', $user_level->id );
	}
	
	return $text; // Returning the default message (from Advanced Settings page)
}

add_filter( 'pmpro_non_member_text_filter', 'pca_non_member_text_filter_by_level', 10, 1 );


/**
 * Return the membership level specific text for RSS feeds
 *
 * @param string $text
 *
 * @return string
 */
function pca_rss_text_filter_by_level( $text ) {
	
	global $current_user;
	$user_level = pmpro_getMembershipLevelForUser( $current_user->ID );
	
	if ( isset( $user_level->id ) ) {
		return pca_get_level_messages( 'rss', $user_level->id );
	}
	
	return $text; // Return the default RSS text (from Advanced Settings page)
}

add_filter( 'pmpro_rss_text_filter', 'pca_rss_text_filter_by_level', 10, 1 );

/**
 * Define and return the text to use based on the supplied $type and Level ID value
 *
 * @param string $type     Type of message (rss|not_logged_in|non_member)
 * @param int    $level_id Membership Level ID
 *
 * @return string
 */
function pca_get_level_messages( $type, $level_id ) {
	
	/**
	 * Format: array(
	 *      level 1 ID => array(
	 *          'rss' => 'User doesn't have access to RSS feed message',
	 *          'not_logged_in' => 'User isn't logged in message',
	 *          'non_member' => 'User isn't a current/active member message'
	 *      ),
	 *      level 2 ID => array(
	 *          'rss' => 'User doesn't have access to RSS feed message',
	 *          'not_logged_in' => 'User isn't logged in message',
	 *          'non_member' => 'User isn't a current/active member message'
	 *      ),
	 *      level 3 ID => array(
	 *          'rss' => 'User doesn't have access to RSS feed message',
	 *          'not_logged_in' => 'User isn't logged in message',
	 *          'non_member' => 'User isn't a current/active member message'
	 *      ),
	 *   )
	 *
	 * FIXME: Update this array to match your needs!
	 */
	$messages = array(
		
		// For user w/level ID # 0 (This can only mean the user isn't a member, and/or aren't logged in...)
		0 => array(
			'rss'           => "Default RSS message for guest users, or users who haven't logged in. Use substitution variables like on the Advanced Settings page",
			'non_member'    => "Not active member, or not logged in. Use substitution variables like on the Advanced Settings page",
		),
		// For membership Level with ID # 1
		1 => array(
			'rss'           => "Level specific RSS message for when user is logged in, but doesn't have access. Use substitution variables like on the Advanced Settings page",
			'non_member'    => "Level specific Not A Member Of This Level message for when user is logged in, but doesn't have access. Use substitution variables like on the Advanced Settings page",
		),
		// For membership Level with ID # 4
		4 => array(
			'rss'           => "Level specific RSS message for when user is logged in, but doesn't have access. Use substitution variables like on the Advanced Settings page",
			'non_member'    => "Level specific Not A Member Of This Level message for when user is logged in, but doesn't have access. Use substitution variables like on the Advanced Settings page",
		),
		// Etc...
	);
	
	return $messages[ $level_id ][ $type ];
}