registration form

add_filter( 'register_form', 'adding_custom_registration_fields' );
function adding_custom_registration_fields( ) {

echo '<div class="form-row form-row-wide"><label for="reg_persontype">'.__('Person Type', 'woocommerce').' <span class="required">*</span></label>
<select name="persontype" id="reg_persontype" class="select" value="'.esc_attr($_POST['persontype']).'" >
                        <option value="0" >Seleziona</option>
                        <option value="1" >Utente</option>
                        <option value="2" >Studente</option>
                        <option value="3" >Scuola</option>
                    </select>';
echo '<div class="form-row form-row-first" id="divfirst"><label for="reg_firstname">'.__('First Name', 'woocommerce').' <span class="required">*</span></label>
<input type="text" class="input-text" name="firstname" id="reg_firstname" value="'.esc_attr($_POST['firstname']).'" /></div>';
echo '<div class="form-row form-row-last" id="divlast"><label for="reg_lastname">'.__('Last Name', 'woocommerce').' <span class="required">*</span></label>
<input type="text" class="input-text" name="lastname" id="reg_lastname" value="'.esc_attr($_POST['lastname']).'" /></div>';

echo '<div class="form-row form-row-wide" id="billing_cpf_field"><label for="reg_codicefiscale">'.__('Codice Fiscale', 'woocommerce').' <span class="required">*</span></label>
<input type="text" class="input-text" name="codicefiscale" id="reg_codicefiscale" value="'.esc_attr($_POST['codicefiscale']).'" /></div>';
echo '<div class="form-row form-row-wide" id="billing_company_field"><label for="reg_azienda">'.__('Azienda', 'woocommerce').' <span class="required">*</span></label>
<input type="text" class="input-text" name="azienda" id="reg_azienda" value="'.esc_attr($_POST['azienda']).'" /></div>';
echo '<div class="form-row form-row-wide" id="billing_cnpj_field"><label for="reg_iva">'.__('P. Iva', 'woocommerce').' <span class="required">*</span></label>
<input type="text" class="input-text" name="iva" id="reg_iva" value="'.esc_attr($_POST['iva']).'" /></div>';

                    echo '</div>';
                    ?>

                    <script>
            jQuery(document).ready(function($) {
    // Required fields.
    $('#billing_company_field label, #billing_cpf_field label, #billing_cnpj_field label').append(' <abbr class="required" title="obrigatório">*</abbr>');

    // Hide and show cpf and cnpj fields
    function personTypeFields(current) {
        $('#divfirst').hide();
        $('#divlast').hide();
        $('#billing_cpf_field').hide();
        $('#billing_company_field').hide();
        $('#billing_cnpj_field').hide();

        if (current == 1) {
            $('#divfirst').show();
            $('#divlast').show();
            $('#billing_cpf_field').show();
        }

        if (current == 2) {
            $('#divfirst').show();
            $('#divlast').show();
            $('#billing_cpf_field').show();
        }

        if (current == 3){
            $('#billing_company_field').show();
            $('#billing_cnpj_field').show();
        }
    }
    personTypeFields($('#reg_persontype').val());

    $('#reg_persontype').on('change', function() {
        var current = $(this).val();

        personTypeFields(current);
    });
});
</script>
<?php
}

//Validation registration form  after submission using the filter registration_errors
add_filter('registration_errors', 'registration_errors_validation', 10,3);
function registration_errors_validation($reg_errors, $sanitized_user_login, $user_email) {
        global $woocommerce;
        extract($_POST); // extracting $_POST into separate variables
        if($firstname == '' ) {
            $woocommerce->add_error( __( '<strong>Nome</strong> obbligatorio', 'woocommerce' ) );
        }
        if($lastname == '' ) {
            $woocommerce->add_error( __( '<strong>Cognome</strong> obbligatorio', 'woocommerce' ) );
        }
        if($persontype == 0 ) {
            $woocommerce->add_error( __( '<strong>Tipo di Persona</strong> obbligatorio', 'woocommerce' ) );
        }
        if ( $persontype == 1 && ! $codicefiscale ) {
                $woocommerce->add_error( __( '<strong>Codice Fiscale</strong> obbligatorio', 'woocommerce' ) );
            }
        /*
        if ( $persontype == 2 && ! $azienda ) {
                $woocommerce->add_error( __( '<strong>Azienda</strong> obbligatorio', 'woocommerce' ) );
            }

        if ( $persontype == 2 && ! $iva ) {
                $woocommerce->add_error( __( '<strong>P. IVA</strong> obbligatorio', 'woocommerce' ) );
            }
        */
        if ( $persontype == 2 && ! $codicefiscale ) {
                $woocommerce->add_error( __( '<strong>Codice Fiscale</strong> obbligatorio', 'woocommerce' ) );
            }
        /*
        if ( $persontype == 3 && ! $iva ) {
                $woocommerce->add_error( __( '<strong>P. IVA</strong> obbligatorio', 'woocommerce' ) );
            }
        */
        if ( $persontype == 3 && ! $azienda ) {
                $woocommerce->add_error( __( '<strong>Azienda</strong> obbligatorio', 'woocommerce' ) );
            }

        if ( $persontype == 3 && ! $iva ) {
                $woocommerce->add_error( __( '<strong>P. IVA</strong> obbligatorio', 'woocommerce' ) );
            }
        return $reg_errors;
}

//Updating use meta after registration successful registration
add_action('woocommerce_created_customer','adding_extra_reg_fields');

function adding_extra_reg_fields($user_id) {
    extract($_POST);
    update_user_meta($user_id, 'first_name', $firstname);
    update_user_meta($user_id, 'last_name', $lastname);

        // can also do multiple fields like that
        update_user_meta($user_id, 'first_name', $firstname);
        update_user_meta($user_id, 'last_name', $lastname);
    update_user_meta($user_id, 'billing_first_name', $firstname);
    update_user_meta($user_id, 'billing_last_name', $lastname);
    update_user_meta($user_id, 'billing_cpf', $codicefiscale);
    update_user_meta($user_id, 'billing_company', $azienda);
    update_user_meta($user_id, 'billing_cnpj', $iva);
    //update_user_meta($user_id, 'shipping_first_name', $firstname);
    //update_user_meta($user_id, 'shipping_last_name', $lastname);

}