Wordpress: Update/Re-Assign posts categories

<?php /** * Simple script to update/reassign posts from old categories to new categories. * Creates any new categories that don't yet exist. * Removes old categories that have now been emptied. * * @author Michael Niles <blindmikey@gmail.com> * @version 1.0.0 */ // rudimentary security // requires that script must be loaded by site.com/update_cats.php?8765trfvb=54rhi9s4mmd1 // recommmended you customize the random strings // do NOT leave on server! if ( !isset( $_GET['8765trfvb'] ) || '54rhi9s4mmd1' != $_GET['8765trfvb'] ) { die(); } // Load WP instance require_once( 'wp-config.php' ); require_once( 'wp-load.php' ); // Set vars $limit = -1; // -1 = does all $offset = 0; // if you've got a limit, increment your offset and re-run /** * PUT YOUR REASSIGNMENTS HERE */ $cats_to_change = array( "Old Category Name" => "New Category Name", ); // NO touchy. Here be dragons. $count = 0; foreach ( $cats_to_change as $old_cat => $new_cat ) { // Run through our offsets if ( 0 < $offset ) { $offset--; continue; } // If we're past our limit then stop $count++; if ( $limit < $count && 0 <= $limit ) { echo __LINE__.': Reassignment limit reached. Stopping.<br/>'.PHP_EOL; break; } $old_cat_id = get_cat_ID( $old_cat ); $new_cat_id = get_cat_ID( $new_cat ); // If the old cat is not found, skip if ( ! $old_cat_id ) { echo __LINE__.': Old category NOT found: "'.$old_cat.'"<br/>'.PHP_EOL; echo __LINE__.': Skipping Reassignment for: "'.$old_cat.'"<br/>'.PHP_EOL; continue; } // If the new cat is the same as the old cat, skip if ( $new_cat_id == $old_cat_id ) { echo __LINE__.': New category already exists as Old category: "'.$new_cat.'" = "'.$old_cat.'"<br/>'.PHP_EOL; echo __LINE__.': Skipping Reassignment for: "'.$old_cat.'"<br/>'.PHP_EOL; continue; } // Create New Category if ( ! $new_cat_id ) { echo __LINE__.': New category NOT found: "'.$new_cat.'"<br/>'.PHP_EOL; echo __LINE__.': Creating category for: "'.$new_cat.'"<br/>'.PHP_EOL; $inserted_term = wp_create_category( $new_cat ); if ( 0 == $inserted_term ) { echo __LINE__.': Failure. Could NOT create new category. Skipping.<br/>'.PHP_EOL; continue; } else { $new_cat_id = $inserted_term; echo __LINE__.': Success. Created as cat id: "'.$new_cat_id.'"<br/>'.PHP_EOL; } } else { echo __LINE__.': New category already exists as: "'.$new_cat.'"<br/>'.PHP_EOL; } /** * Get Posts by Old Category */ $posts = get_posts(array( 'posts_per_page' => -1, 'category' => $old_cat_id )); foreach ( $posts as $post ) { $post_id = $post->ID; $cat_ids = wp_get_post_categories( $post_id ); echo __LINE__.': Reassigning categories for post ID: '.$post_id.'<br/>'.PHP_EOL; // remove old category if(($key = array_search($old_cat_id, $cat_ids)) !== false) { echo __LINE__.': Removing old category: "'.$old_cat.'" / ID: '.$old_cat_id.'<br/>'.PHP_EOL; unset($cat_ids[$key]); } // add our new category echo __LINE__.': Adding new category: "'.$new_cat.'" / ID: '.$new_cat_id.'<br/>'.PHP_EOL; $cat_ids[] = $new_cat_id; // prepare our cat_ids $cat_ids = array_map( 'intval', $cat_ids ); $cat_ids = array_unique( $cat_ids ); // set the post to use only these cat_ids wp_set_object_terms( $post_id, $cat_ids, 'category' ); } // we're done with the old - remove it. echo __LINE__.': Deleting old category ID: '.$old_cat_id.'<br/>'.PHP_EOL; wp_delete_category( $old_cat_id ); }