my-pmpro-redirect-to-referring-page-after-checkout-session.php

<?php
/**
 *
 * ===== WARNING =====
 * This code recipe is intended for developers and requires extensive knowledge of websites, and WordPress.
 * Copying and pasting this recipe into your site as-is won't work - you need to follow the steps outlined in this code.
 * If you are unsure, please hire a local WordPress developer or freelance for assistance.
 *
 * This code recipe is experimental and was built for private use, outside of Paid Memberships Pro and it's support scope.
 *
 * USE AT OWN RISK
 * ===================
 *
 * Display the last visited non-PMPro page in the confirmation message, OR
 * redirect the member back to the last visited page.
 *
 * Usage Guide:
 *
 * 1. Set your preference to either display the link or redirect back to
 *    the referrer page by setting the $toggle_display_redirect variable
 *    to true or false.
 * 2. Customize your message for the confirmation page in the $referrer_message
 *    variable.
 *
 * This recipe requires that the "Message for Logged-out Users" and
 * "Message for Logged-in Non-members" setting on the
 * Advanced Settings page (Memberships > Settings > Advanced) has
 * "?redirect_to=!!referrer!!" after the !!levels_page_url!! placeholder.
 *
 * E.g <a href="!!levels_page_url!!?redirect_to=!!referrer!!">Join Now</a>, or
 * <a href="!!login_url!!?redirect_to=!!referrer!!">Login</a> <a href="!!levels_page_url!!?redirect_to=!!referrer!!">Join Now</a>
 */

// Ensure session starts safely
function pmpro_custom_start_session() {
	if ( ! session_id() ) {
		session_start();
	}
}
add_action( 'init', 'pmpro_custom_start_session', 1 );

// Set redirect type: 'redirect' or 'message'
function my_pmpro_redirect_to_referring_page_after_checkout_type() {
	return 'redirect'; // Or 'message'
}

// Customize the confirmation message
function my_pmpro_redirect_to_referring_page_after_checkout_last_visited_message() {
	return esc_html__( 'View your last visited page here: %s.', 'pmpro-customizations' );
}

// Add last page link to confirmation page text
function my_pmpro_redirect_to_referring_page_after_checkout_message( $message ) {
	$last_url = my_pmpro_redirect_to_referring_page_after_checkout_get_safe_url();
	if ( null === $last_url ) {
		return $message;
	}

	$last_visited_message = my_pmpro_redirect_to_referring_page_after_checkout_last_visited_message();
	$last_visited_link    = sprintf( '<a href="%1$s">%2$s</a>', esc_url( $last_url ), esc_html( $last_url ) );
	$message             .= "\n<p>" . sprintf( $last_visited_message, $last_visited_link ) . '</p>';

	unset( $_SESSION['my_pmpro_last_url_before_checkout'] );

	return $message;
}

// Redirect to last page
function my_pmpro_redirect_to_referring_page_after_checkout_redirect( $url ) {
	$last_url = my_pmpro_redirect_to_referring_page_after_checkout_get_safe_url();

	unset( $_SESSION['my_pmpro_last_url_before_checkout'] );

	return $last_url ? $last_url : $url;
}

// Store the last URL visited on each page load
add_action( 'wp', 'my_pmpro_redirect_to_referring_page_after_checkout_track' );
function my_pmpro_redirect_to_referring_page_after_checkout_track() {
	if ( empty( $_REQUEST['redirect_to'] ) ) {
		return;
	}

	global $post, $pmpro_pages;
	$last_url_viewed = sanitize_text_field( $_REQUEST['redirect_to'] );

	if ( $post && $pmpro_pages && in_array( strval( url_to_postid( $last_url_viewed ) ), $pmpro_pages, true ) ) {
		return;
	}

	$_SESSION['my_pmpro_last_url_before_checkout'] = $last_url_viewed;
}

// Add the filter to the confirmation message or confirmation URL
add_action( 'init', 'my_pmpro_redirect_to_referring_page_after_checkout_filter' );
function my_pmpro_redirect_to_referring_page_after_checkout_filter() {
	$type = my_pmpro_redirect_to_referring_page_after_checkout_type();

	if ( 'message' === $type ) {
		add_filter( 'pmpro_confirmation_message', 'my_pmpro_redirect_to_referring_page_after_checkout_message', 20 );
	} elseif ( 'redirect' === $type ) {
		add_filter( 'pmpro_confirmation_url', 'my_pmpro_redirect_to_referring_page_after_checkout_redirect' );
	}
}

// Retrieve the last URL safely
function my_pmpro_redirect_to_referring_page_after_checkout_get_safe_url() {
	if ( empty( $_SESSION['my_pmpro_last_url_before_checkout'] ) ) {
		return null;
	}

	$url = sanitize_text_field( $_SESSION['my_pmpro_last_url_before_checkout'] );
	if ( ! wp_http_validate_url( $url ) ) {
		return null;
	}

	return $url;
}