/**
 * Collect the donor's National ID # in the donation form.
 *
 * Fields are added as a PHP array that define the field. You can customize the 
 * following fields: 
 *
 * label: The label that will be displayed alongside the field.
 * placeholder: Optionally, you can display a placeholder value to be shown inside the field. 
 * type: The type of field. Options: text, checkbox, datepicker, editor, file, multi-checkbox, number, picture, radio, select, textarea, url
 * priority: The priority of the field. This determines where in the form the field is displayed.
 * value: The current/default value of the field.
 * required: Whether the field is required. Set to `true` or `false`.
 * data_type: How the field is saved in the database. The simplest option is to use `user` as in the example below, which will automatically save the field to the user meta table.
 *
 * @param   array[] $fields
 * @param   Charitable_Donation_Form $form
 * @return  array[]
 */
function ed_collect_national_id_number($fields, Charitable_Donation_Form $form)
{
    /**
     * If you only want to collect a certain field on a certain campaign's 
     * donation form, uncomment this next section and replace 1234 with the
     * ID of your campaign.
     */
    // if ( 1234 != $form->get_campaign()->ID ) {
    //     return $fields;
    // }
    $fields['national_id_number'] = array('label' => __('National ID Number', 'your-namespace'), 'type' => 'text', 'priority' => 24, 'value' => $form->get_user_value('donor_national_id_number'), 'required' => true, 'data_type' => 'user');
    return $fields;
}
/**
 * Collect the donor's National ID # in the donation form.
 *
 * @param   array[] $fields
 * @param   Charitable_Donation_Form $form
 * @return  array[]
 */
function ed_collect_national_id_number($fields, Charitable_Donation_Form $form)
{
    $fields['national_id_number'] = array('label' => __('National ID Number', 'your-namespace'), 'type' => 'text', 'priority' => 24, 'value' => $form->get_user_value('donor_national_id_number'), 'required' => true, 'data_type' => 'user');
    return $fields;
}