<?php
/**
* Plugin Name: External Permalinks Redux
* Plugin URI: http://www.thinkoomph.com/plugins-modules/external-permalinks-redux/
* Description: Allows users to point WordPress objects (posts, pages, custom post types) to a URL of your choosing. Inspired by and backwards-compatible with <a href="http://txfx.net/wordpress-plugins/page-links-to/">Page Links To</a> by Mark Jaquith. Written for use on WordPress.com VIP.
* Version: 1.2
* Author: Erick Hitter & Oomph, Inc.
* Author URI: http://www.thinkoomph.com/
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* @package External_Permalinks_Redux
*/
// Include block-editor class.
require_once __DIR__ . '/inc/class-external-permalinks-redux-block-editor.php';
/**
* Class external_permalinks_redux.
*/
// phpcs:ignore PEAR.NamingConventions.ValidClassName, Squiz.Commenting.ClassComment.Missing
class external_permalinks_redux {
/**
* Singleton!
*
* @var self
*/
protected static $instance;
/**
* Redirect URL meta key.
*
* @var string
*/
public $meta_key_target = '_links_to';
/**
* Redirect type meta key.
*
* @var string
*/
public $meta_key_type = '_links_to_type';
/**
* Supported redirect codes.
*
* @var array
*/
public $status_codes;
/**
* Instance of the block-editor integration class.
*
* @var External_Permalinks_Redux_Block_Editor
*/
public $block_editor;
/**
* Instantiate class as a singleton.
*
* @return object
*/
public static function get_instance() {
if ( ! isset( self::$instance ) ) {
self::$instance = new self();
}
return self::$instance;
}
/**
* Register actions and filters.
*/
private function __construct() {
add_action( 'init', array( $this, 'action_init' ), 0 ); // Other init actions may rely on permalinks so filter early.
add_action( 'admin_init', array( $this, 'action_admin_init' ) );
add_action( 'save_post', array( $this, 'action_save_post' ) );
add_filter( 'post_link', array( $this, 'filter_post_permalink' ), 1, 2 );
add_filter( 'post_type_link', array( $this, 'filter_post_permalink' ), 1, 2 );
add_filter( 'page_link', array( $this, 'filter_page_link' ), 1, 2 );
add_action( 'wp', array( $this, 'action_wp' ) );
$this->block_editor = new External_Permalinks_Redux_Block_Editor();
}
/**
* Register plugin keys and status codes.
*
* @action init
*/
public function action_init() {
$this->meta_key_target = apply_filters( 'epr_meta_key_target', $this->meta_key_target );
$this->meta_key_type = apply_filters( 'epr_meta_key_type', $this->meta_key_type );
$status_codes = array(
302 => __( 'Temporary (302)', 'external-permalinks-redux' ),
301 => __( 'Permanent (301)', 'external-permalinks-redux' ),
);
$this->status_codes = apply_filters( 'epr_status_codes', $status_codes );
}
/**
* Add meta box.
*/
public function action_admin_init() {
$post_types = apply_filters( 'epr_post_types', array( 'post', 'page' ) );
if ( ! is_array( $post_types ) ) {
return;
}
foreach ( $post_types as $post_type ) {
$title = apply_filters( 'epr_metabox_title', '', $post_type );
if ( ! $title ) {
$title = __( 'External Permalinks Redux', 'external-permalinks-redux' );
}
add_meta_box( 'external-permalinks-redux', $title, array( $this, 'meta_box' ), $post_type, 'normal' );
unset( $title );
}
}
/**
* Render meta box.
*
* @param object $post Post object.
*/
public function meta_box( $post ) {
$type = get_post_meta( $post->ID, $this->meta_key_type, true );
?>
<p class="epr-destination">
<label for="epr-url"><?php esc_html_e( 'Destination Address:', 'external-permalinks-redux' ); ?></label><br />
<input name="<?php echo esc_attr( $this->meta_key_target ); ?>_url" class="large-text code" id="epr-url" type="text" value="<?php echo esc_url( get_post_meta( $post->ID, $this->meta_key_target, true ) ); ?>" />
</p>
<p class="description"><?php esc_html_e( 'To restore the original permalink, remove the link entered above.', 'external-permalinks-redux' ); ?></p>
<p class="epr-separator"> </p>
<p class="epr-redirect-type">
<label for="epr-type"><?php esc_html_e( 'Redirect Type:', 'external-permalinks-redux' ); ?></label>
<select name="<?php echo esc_attr( $this->meta_key_target ); ?>_type" id="epr-type">
<option value=""><?php esc_html_e( '-- Select --', 'external-permalinks-redux' ); ?></option>
<?php
foreach ( $this->status_codes as $status_code => $explanation ) {
echo '<option value="' . esc_attr( $status_code ) . '"';
selected( $status_code, (int) $type );
echo '>' . esc_html( $explanation ) . '</option>';
}
?>
</select>
</p>
<?php
wp_nonce_field( 'external-permalinks-redux', $this->meta_key_target . '_nonce', false );
}
/**
* Save meta box input.
*
* @param int $post_id Post ID.
*/
public function action_save_post( $post_id ) {
if ( isset( $_POST[ $this->meta_key_target . '_nonce' ] ) && wp_verify_nonce( sanitize_text_field( $_POST[ $this->meta_key_target . '_nonce' ] ), 'external-permalinks-redux' ) ) {
// Target.
$url = isset( $_POST[ $this->meta_key_target . '_url' ] ) ? esc_url_raw( $_POST[ $this->meta_key_target . '_url' ] ) : '';
if ( ! empty( $url ) ) {
update_post_meta( $post_id, $this->meta_key_target, $url );
} else {
delete_post_meta( $post_id, $this->meta_key_target, $url );
}
// Redirect type.
$type = isset( $_POST[ $this->meta_key_target . '_type' ] ) ? (int) $_POST[ $this->meta_key_target . '_type' ] : '';
if ( ! empty( $url ) && array_key_exists( $type, $this->status_codes ) ) {
update_post_meta( $post_id, $this->meta_key_type, $type );
} else {
delete_post_meta( $post_id, $this->meta_key_type );
}
}
}
/**
* Filter post and custom post type permalinks.
*
* @param string $permalink Post permalinks.
* @param object $post Post object.
* @return string
*/
public function filter_post_permalink( $permalink, $post ) {
$external_link = get_post_meta( $post->ID, $this->meta_key_target, true );
if ( ! empty( $external_link ) ) {
$permalink = $external_link;
}
return $permalink;
}
/**
* Filter page permalinks.
*
* @param string $link Page permalink.
* @param int $id Post ID.
* @return string
*/
public function filter_page_link( $link, $id ) {
$external_link = get_post_meta( $id, $this->meta_key_target, true );
if ( ! empty( $external_link ) ) {
$link = $external_link;
}
return $link;
}
/**
* Redirect to external link if object requested directly.
*/
public function action_wp() {
global $post;
if ( ! is_singular() ) {
return;
}
$redirect = $this->get_redirect_data( $post->ID );
if ( false === $redirect ) {
return;
}
// Unreasonable to validate redirect destination.
// phpcs:ignore WordPress.Security.SafeRedirect.wp_redirect_wp_redirect
wp_redirect( $redirect['link'], $redirect['type'] );
exit;
}
/**
* Retrieve redirect data for a given post ID.
*
* @param int $post_id Post ID.
* @return array|bool
*/
public function get_redirect_data( $post_id ) {
if ( ! is_numeric( $post_id ) ) {
return false;
}
$link = get_post_meta( $post_id, $this->meta_key_target, true );
if ( empty( $link ) ) {
return false;
}
$type = (int) get_post_meta( $post_id, $this->meta_key_type, true );
$type = apply_filters( 'epr_status_code', $type, $link, get_post( $post_id ) );
if ( ! $type ) {
$type = 302;
}
return compact( 'link', 'type' );
}
}
// Initialize the plugin if it hasn't already.
external_permalinks_redux::get_instance();
/**
* Wrapper for meta box function.
*
* Can be used as an alternative to the `epr_post_types` filter
* found in the plugin class's `action_admin_init` function.
*
* @param object $post Post object.
*/
function external_permalinks_redux_meta_box( $post ) {
external_permalinks_redux::get_instance()->meta_box( $post );
}