Pretty formating repeater values in Send Email action content

jet-fb-repeater-format-email.php

<?php

/**
 * Works in JetFormBuilder >= 2.1.0
 */
 
add_filter(
	'jet-form-builder/send-email/template-repeater',
	/**
	 * Verbose repeater items array
	 *
	 * @param string $content
	 * @param array $items
	 * @param \Jet_Form_Builder\Classes\Macros_Parser $parser
	 *
	 * @return string
	 */
	function ( string $content, array $items, $parser ) {

		/** @var \Jet_Form_Builder\Actions\Types\Send_Email $action */
		$action  = jet_fb_action_handler()->get_current_action();
		$is_html = 'text/html' === $action->get_content_type();

		$index          = 0;
		$separator      = $is_html ? '<br>' : "\n\r";
		$tab            = $is_html ? '&emsp;' : "\t";
		$repeater_label = 'Repeater Heading';
		$repeater_name  = function_exists( 'jet_fb_context' ) ? $parser->get_current_macro() : '';

		$rows = array();

		$if_array = function ( $value ) {
			return is_array( $value ) ? implode( ', ', $value ) : $value;
		};

		foreach ( $items as $item ) {
			$item_data = array();

			foreach ( $item as $key => $value ) {
				// for JetFormBuilder >= 3.1
				if ( function_exists( 'jet_fb_context' ) ) {
					$label = jet_fb_context()->get_setting( 'label', array( $repeater_name, $index, $key ) );
				} else {
					$label = jet_fb_request_handler()->get_attr( $key, 'label', $key );
				}

				$item_data[] = sprintf( '%1$s: %2$s', $label, call_user_func( $if_array, $value ) );
			}
			$row  = 'Repeater Item ' . ++$index . $separator . $tab;
			$row .= implode( $separator . $tab, $item_data );

			$rows[] .= $row;
		}

		return ( $separator . $repeater_label . $separator . implode( $separator, $rows ) );
	},
	10,
	3
);