GiveWP Add Email Tag for Donor Last Name

givewp_donor_last_name_email_tag.php

function givewp_get_donor_last_name() {
	give_add_email_tag(
		array(
			'tag'      => 'lastname', // The tag name.
			'desc'     => __( 'The last name of the donor.', 'give' ),
			'func'     => 'givewp_get_donor_last_name_tag', // Callback to function below.
			'context'  => 'donation', // This tag can be for both admin and donor notifications.
			'is_admin' => false, // default is false. This is here to simply display it as an option.
        )
    );
}

add_action( 'give_add_email_tags', 'givewp_get_donor_last_name' );

function givewp_get_donor_last_name_tag( $tag_args ) {
	$donor_info = array();
	$lastname = '';


	switch ( true ) {
		case give_check_variable( $tag_args, 'isset', 0, 'payment_id' ):
			$donor_info  = give_get_payment_meta_user_info( $tag_args['payment_id'] );
			$lastname   = $donor_info['last_name'];

			break;

		case give_check_variable( $tag_args, 'isset', 0, 'user_id' ):
			$lastname = Give()->donor_meta->get_meta(
				Give()->donors->get_column_by( 'id', 'user_id', $tag_args['user_id'] ),
				'_give_donor_last_name',
				true
			);
			break;

		/**
		 * Get Donor First Name from donor id
		 *
		 * @since 2.0
		 */
		case give_check_variable( $tag_args, 'isset', 0, 'donor_id' ):
			$lastname = Give()->donor_meta->get_meta( $tag_args['donor_id'], '_give_donor_last_name', true );
			break;
	}


	return $lastname;
}
// Only add this function if you want to add the tag to PDF receipts
function give_add_lastname_pdf_tag( $template_content, $args ) {
	$lastname     = isset( $args['payment_meta']['_give_donor_billing_last_name'] ) ? $args['payment_meta']['_give_donor_billing_last_name'] : '';
	$template_content = str_replace( '{lastname}', $lastname, $template_content );
	return $template_content;
}

add_filter( 'give_pdf_compiled_template_content', 'give_add_lastname_pdf_tag', 999, 2 );