Filter field parameters before saving

You can filter your field parameters before they’re saved if you wish. In the example below, we’re setting a calculation field to be flat rate:

	<?php
	/**
	* Filter our field params before they're saved
	* In this case, set a calculation field with the ID 4991 to be flat rate
	* @requires 3.4.3 and greater
	*/
	function prefix_before_update_field_all_params( $all_params, $field_id ) {
	if( $field_id == 4991 ) {
	$all_params['field_flatrate'] = 1;
	}
	return $all_params;
	}
	add_filter( 'pewc_before_update_field_all_params', 'prefix_before_update_field_all_params', 10, 2 );