DataTables footerCallback Extension

tablepress-datatables-footercallback.php

<?php
/*
Plugin Name: TablePress Extension: Custom "footerCallback"
Plugin URI: http://tablepress.org/extensions/
Description: Custom Extension for TablePress to add a "footerCallback"
Version: 1.0
Author: Tobias Bäthge
Author URI: http://tobias.baethge.com/
*/
add_filter( 'tablepress_datatables_parameters', 'tablepress_datatables_custom_footercallback', 10, 4 );
/**
 * Add a custom "footerCallback".
 *
 * @since 1.0.0
 *
 * @param array  $parameters DataTables parameters.
 * @param string $table_id   Table ID.
 * @param string $html_id    HTML ID of the table.
 * @param array  $js_options JS options for DataTables.
 * @return array Extended DataTables parameters.
 */
function tablepress_datatables_custom_footercallback( $parameters, $table_id, $html_id, $js_options ) {
	if ( in_array( $table_id, array( '1', '4 ') ) ) {
		$parameters['footerCallback'] = <<<JS
"footerCallback": function ( row, data, start, end, display ) {
            var api = this.api(), data;
 
            // Remove the formatting to get integer data for summation
            var intVal = function ( i ) {
                return typeof i === 'string' ?
                    i.replace(/[\$,]/g, '')*1 :
                    typeof i === 'number' ?
                        i : 0;
            };
 
            // Total over all pages
            total = api
                .column( 4 )
                .data()
                .reduce( function (a, b) {
                    return intVal(a) + intVal(b);
                } );
 
            // Total over this page
            pageTotal = api
                .column( 4, { page: 'current'} )
                .data()
                .reduce( function (a, b) {
                    return intVal(a) + intVal(b);
                }, 0 );
 
            // Update footer
            $( api.column( 4 ).footer() ).html(
                '$'+pageTotal +' ( $'+ total +' total)'
            );
        }
JS;
	}
	return $parameters;
}