Duplicate custom post in Wordpress

duplicate-custom-posts-works.php

<?php

// @snippet  Duplicate posts and pages without plugins
// @author   Misha Rudrastyh
// @url      https://rudrastyh.com/wordpress/duplicate-post.html

// Add the duplicate link to action list for post_row_actions
// for "post" and custom post types
add_filter( 'post_row_actions', 'rd_duplicate_post_link', 10, 2 );
// for "page" post type
add_filter( 'page_row_actions', 'rd_duplicate_post_link', 10, 2 );


function rd_duplicate_post_link( $actions, $post ) {

  if( ! current_user_can( 'edit_posts' ) ) {
    return $actions;
  }

  $url = wp_nonce_url(
    add_query_arg(
      array(
        'action' => 'rd_duplicate_post_as_draft',
        'post' => $post->ID,
      ),
      'admin.php'
    ),
    basename(__FILE__),
    'duplicate_nonce'
  );

  $actions[ 'duplicate' ] = '<a href="' . $url . '" title="Duplicate this item" rel="permalink">Duplicate</a>';

  return $actions;
}

/*
 * Function creates post duplicate as a draft and redirects then to the edit post screen
 */
add_action( 'admin_action_rd_duplicate_post_as_draft', 'rd_duplicate_post_as_draft' );

function rd_duplicate_post_as_draft(){

  // check if post ID has been provided and action
  if ( empty( $_GET[ 'post' ] ) ) {
    wp_die( 'No post to duplicate has been provided!' );
  }

  // Nonce verification
  if ( ! isset( $_GET[ 'duplicate_nonce' ] ) || ! wp_verify_nonce( $_GET[ 'duplicate_nonce' ], basename( __FILE__ ) ) ) {
    return;
  }

  // Get the original post id
  $post_id = absint( $_GET[ 'post' ] );

  // And all the original post data then
  $post = get_post( $post_id );

  /*
   * if you don't want current user to be the new post author,
   * then change next couple of lines to this: $new_post_author = $post->post_author;
   */
  $current_user = wp_get_current_user();
  $new_post_author = $current_user->ID;

  // if post data exists (I am sure it is, but just in a case), create the post duplicate
  if ( $post ) {

    // new post data array
    $args = array(
      'comment_status' => $post->comment_status,
      'ping_status'    => $post->ping_status,
      'post_author'    => $new_post_author,
      'post_content'   => $post->post_content,
      'post_excerpt'   => $post->post_excerpt,
      'post_name'      => $post->post_name,
      'post_parent'    => $post->post_parent,
      'post_password'  => $post->post_password,
      'post_status'    => 'draft',
      'post_title'     => $post->post_title,
      'post_type'      => $post->post_type,
      'to_ping'        => $post->to_ping,
      'menu_order'     => $post->menu_order
    );

    // insert the post by wp_insert_post() function
    $new_post_id = wp_insert_post( $args );

    /*
     * get all current post terms ad set them to the new post draft
     */
    $taxonomies = get_object_taxonomies( get_post_type( $post ) ); // returns array of taxonomy names for post type, ex array("category", "post_tag");
    if( $taxonomies ) {
      foreach ( $taxonomies as $taxonomy ) {
        $post_terms = wp_get_object_terms( $post_id, $taxonomy, array( 'fields' => 'slugs' ) );
        wp_set_object_terms( $new_post_id, $post_terms, $taxonomy, false );
      }
    }

    // duplicate all post meta
    $post_meta = get_post_meta( $post_id );
    if( $post_meta ) {

      foreach ( $post_meta as $meta_key => $meta_values ) {

        if( '_wp_old_slug' == $meta_key ) { // do nothing for this meta key
          continue;
        }

        foreach ( $meta_values as $meta_value ) {
          add_post_meta( $new_post_id, $meta_key, $meta_value );
        }
      }
    }

    // finally, redirect to the edit post screen for the new draft
    // wp_safe_redirect(
    //  add_query_arg(
    //    array(
    //      'action' => 'edit',
    //      'post' => $new_post_id
    //    ),
    //    admin_url( 'post.php' )
    //  )
    // );
    // exit;
    // or we can redirect to all posts with a message
    wp_safe_redirect(
      add_query_arg(
        array(
          'post_type' => ( 'post' !== get_post_type( $post ) ? get_post_type( $post ) : false ),
          'saved' => 'post_duplication_created' // just a custom slug here
        ),
        admin_url( 'edit.php' )
      )
    );
    exit;

  } else {
    wp_die( 'Post creation failed, could not find original post.' );
  }

}

/*
 * In case we decided to add admin notices
 */
add_action( 'admin_notices', 'rudr_duplication_admin_notice' );

function rudr_duplication_admin_notice() {

  // Get the current screen
  $screen = get_current_screen();

  if ( 'edit' !== $screen->base ) {
    return;
  }

    //Checks if settings updated
    if ( isset( $_GET[ 'saved' ] ) && 'post_duplication_created' == $_GET[ 'saved' ] ) {

     echo '<div class="notice notice-success is-dismissible"><p>Post copy created.</p></div>';
     
    }
}

duplicate-custom-posts.php

<?php

// From https://www.hostinger.co.uk/tutorials/how-to-duplicate-wordpress-page-or-post#:~:text=Go%20to%20your%20WordPress%20dashboard,there%20%E2%80%93%20Clone%20and%20New%20Draft.
// The duplicate script in PHP for custom posts
/*
 * Function for post duplication. Dups appear as drafts. User is redirected to the edit screen
 */
function rd_duplicate_post_as_draft(){
  global $wpdb;
  if (! ( isset( $_GET['post']) || isset( $_POST['post'])  || ( isset($_REQUEST['action']) && 'rd_duplicate_post_as_draft' == $_REQUEST['action'] ) ) ) {
    wp_die('No post to duplicate has been supplied!');
  }
 
  /*
   * Nonce verification
   */
  if ( !isset( $_GET['duplicate_nonce'] ) || !wp_verify_nonce( $_GET['duplicate_nonce'], basename( __FILE__ ) ) )
    return;
 
  /*
   * get the original post id
   */
  $post_id = (isset($_GET['post']) ? absint( $_GET['post'] ) : absint( $_POST['post'] ) );
  /*
   * and all the original post data then
   */
  $post = get_post( $post_id );
 
  /*
   * if you don't want current user to be the new post author,
   * then change next couple of lines to this: $new_post_author = $post->post_author;
   */
  $current_user = wp_get_current_user();
  $new_post_author = $current_user->ID;
 
  /*
   * if post data exists, create the post duplicate
   */
  if (isset( $post ) && $post != null) {
 
    /*
     * new post data array
     */
    $args = array(
      'comment_status' => $post->comment_status,
      'ping_status'    => $post->ping_status,
      'post_author'    => $new_post_author,
      'post_content'   => $post->post_content,
      'post_excerpt'   => $post->post_excerpt,
      'post_name'      => $post->post_name,
      'post_parent'    => $post->post_parent,
      'post_password'  => $post->post_password,
      'post_status'    => 'draft',
      'post_title'     => $post->post_title,
      'post_type'      => $post->post_type,
      'to_ping'        => $post->to_ping,
      'menu_order'     => $post->menu_order
    );
 
    /*
     * insert the post by wp_insert_post() function
     */
    $new_post_id = wp_insert_post( $args );
 
    /*
     * get all current post terms ad set them to the new post draft
     */
    $taxonomies = get_object_taxonomies($post->post_type); // returns array of taxonomy names for post type, ex array("category", "post_tag");
    foreach ($taxonomies as $taxonomy) {
      $post_terms = wp_get_object_terms($post_id, $taxonomy, array('fields' => 'slugs'));
      wp_set_object_terms($new_post_id, $post_terms, $taxonomy, false);
    }
 
    /*
     * duplicate all post meta just in two SQL queries
     */
    $post_meta_infos = $wpdb->get_results("SELECT meta_key, meta_value FROM $wpdb->postmeta WHERE post_id=$post_id");
    if (count($post_meta_infos)!=0) {
      $sql_query = "INSERT INTO $wpdb->postmeta (post_id, meta_key, meta_value) ";
      foreach ($post_meta_infos as $meta_info) {
        $meta_key = $meta_info->meta_key;
        if( $meta_key == '_wp_old_slug' ) continue;
        $meta_value = addslashes($meta_info->meta_value);
        $sql_query_sel[]= "SELECT $new_post_id, '$meta_key', '$meta_value'";
      }
      $sql_query.= implode(" UNION ALL ", $sql_query_sel);
      $wpdb->query($sql_query);
    }
 
 
    /*
     * finally, redirect to the edit post screen for the new draft
     */
    wp_redirect( admin_url( 'post.php?action=edit&post=' . $new_post_id ) );
    exit;
  } else {
    wp_die('Post creation failed, could not find original post: ' . $post_id);
  }
}
add_action( 'admin_action_rd_duplicate_post_as_draft', 'rd_duplicate_post_as_draft' );
 
/*
 * Add the duplicate link to action list for post_row_actions
 */
function rd_duplicate_post_link( $actions, $post ) {
  if (current_user_can('edit_posts')) {
    $actions['duplicate'] = '<a href="' . wp_nonce_url('admin.php?action=rd_duplicate_post_as_draft&post=' . $post->ID, basename(__FILE__), 'duplicate_nonce' ) . '" title="Duplicate this item" rel="permalink">Duplicate</a>';
  }
  return $actions;
}
 
add_filter( 'post_row_actions', 'rd_duplicate_post_link', 10, 2 );


?>