WordPress - Add custom sortable columns for custom post type.

custom-sortable-columns.php

<?php
/**
 * Add custom column
 * 
 * @todo Change the `prefix_` and with your own unique prefix.
 * 
 * @since 1.0.0
 */
if( ! function_exists( 'prefix_add_custom_column' ) ) :
	function prefix_add_custom_column( $columns = array() ) {

		$new_columns = array(
			'portfolio-type' => __( 'Portfolio Type', 'textdomain' ),
		);

    	return wp_parse_args( $new_columns, $columns );
   }
   add_filter('manage_astra-portfolio_posts_columns', 'prefix_add_custom_column', 10);
endif;

/**
 * Column markup
 * 
 * @todo Change the `prefix_` and with your own unique prefix.
 * 
 * @since 1.0.0
 *
 * @param  string Column slug.
 * @param  integer Post ID.
 * @return void
 */
if( ! function_exists( 'prefix_custom_column_markup' ) ) :
	function prefix_custom_column_markup( $column_name = '', $post_id = 0 ) {

		if ( $column_name == 'portfolio-type') {
	        echo get_post_meta( $post_id, 'astra-portfolio-type', true );
	    }

   }
   add_action('manage_astra-portfolio_posts_custom_column', 'prefix_custom_column_markup', 10, 2);
endif;




/**
 * Add Sortable Column
 * 
 * @todo Change the `prefix_` and with your own unique prefix.
 * 
 * @since 1.0.0
 *
 * @param  array $columns  Columns.
 * @return array
 */
if( ! function_exists( 'prefix_add_custom_sortable_column' ) ) :
	function prefix_add_custom_sortable_column( $columns = array() ) {
		$new_columns = array(
			'portfolio-type' => 'portfolio-type',
		);

		return wp_parse_args( $new_columns, $columns );
   }
   add_filter('manage_edit-astra-portfolio_sortable_columns', 'prefix_add_custom_sortable_column' ); 
endif;

/**
 * Perform order by custom colum.
 * 
 * @todo Change the `prefix_` and with your own unique prefix.
 * 
 * @since 1.0.0
 *
 * @param  array $columns  Columns.
 * @return array
 */
if( ! function_exists( 'prefix_perform_custom_sortable_order' ) ) :
	function prefix_perform_custom_sortable_order( $query ) {
		if( ! is_admin() || ! $query->is_main_query() ) {
		    return;
		  }

		  $orderby = $query->get( 'orderby');

		  if ( 'portfolio-type' == $orderby ) {
				$query->set( 'meta_key', 'astra-portfolio-type' );
				$query->set( 'orderby', 'meta_value' );
		  }
   	}
   add_action( 'pre_get_posts', 'prefix_perform_custom_sortable_order' );
endif;