[Edit checkout form] #woo

edit-checkout-form.php

//source: https://www.cloudways.com/blog/how-to-edit-delete-fields-and-email-in-woocommerce-custom-checkout-fields/

//remove first name and last name.
function woocommerce_remove_additional_information_checkout($fields){
    unset( $fields["billing_first_name"] );
    unset( $fields["billing_last_name"] );
    return $fields;
}
add_filter( 'woocommerce_billing_fields', 'woocommerce_remove_additional_information_checkout' );

//add a new field
function cloudways_custom_checkout_fields($fields){
    $fields['cloudways_extra_fields'] = array(
            'cloudways_text_field' => array(
                'type' => 'text',
                'required'      => true,
                'label' => __( 'Input Text Field' )
                ),
            'cloudways_dropdown' => array(
                'type' => 'select',
                'options' => array( 'first' => __( 'First Option' ), 'second' => __( 'Second Option' ), 'third' => __( 'Third Option' ) ),
                'required'      => true,
                'label' => __( 'Dropdown field' )
                )
            );
    return $fields;
}
add_filter( 'woocommerce_checkout_fields', 'cloudways_custom_checkout_fields' );
function cloudways_extra_checkout_fields(){
    $checkout = WC()->checkout(); ?>
    <div class="extra-fields">
    <h3><?php _e( 'Additional Fields' ); ?></h3>
    <?php
       foreach ( $checkout->checkout_fields['cloudways_extra_fields'] as $key => $field ) : ?>
            <?php woocommerce_form_field( $key, $field, $checkout->get_value( $key ) ); ?>
        <?php endforeach; ?>
    </div>
<?php }
add_action( 'woocommerce_checkout_after_customer_details' ,'cloudways_extra_checkout_fields' );

//save newly added field
function cloudways_save_extra_checkout_fields( $order_id, $posted ){
    // don't forget appropriate sanitization if you are using a different field type
    if( isset( $posted['cloudways_text_field'] ) ) {
        update_post_meta( $order_id, '_cloudways_text_field', sanitize_text_field( $posted['cloudways_text_field'] ) );
    }
    if( isset( $posted['cloudways_dropdown'] ) && in_array( $posted['cloudways_dropdown'], array( 'first', 'second', 'third' ) ) ) {
        update_post_meta( $order_id, '_cloudways_dropdown', $posted['cloudways_dropdown'] );
    }
}
add_action( 'woocommerce_checkout_update_order_meta', 'cloudways_save_extra_checkout_fields', 10, 2 );

//use newly added form field data
function cloudways_display_order_data( $order_id ){  ?>
    <h2><?php _e( 'Extra Information' ); ?></h2>
    <table class="shop_table shop_table_responsive additional_info">
        <tbody>
            <tr>
                <th><?php _e( 'Input Text Field:' ); ?></th>
                <td><?php echo get_post_meta( $order_id, '_cloudways_text_field', true ); ?></td>
            </tr>
            <tr>
                <th><?php _e( 'Drop Down Field:' ); ?></th>
                <td><?php echo get_post_meta( $order_id, '_cloudways_dropdown', true ); ?></td>
            </tr>
        </tbody>
    </table>
<?php }
add_action( 'woocommerce_thankyou', 'cloudways_display_order_data', 20 );
add_action( 'woocommerce_view_order', 'cloudways_display_order_data', 20 );

//display in admin area
function cloudways_display_order_data_in_admin( $order ){  ?>
    <div class="order_data_column">
        <h4><?php _e( 'Additional Information', 'woocommerce' ); ?><a href="#" class="edit_address"><?php _e( 'Edit', 'woocommerce' ); ?></a></h4>
        <div class="address">
        <?php
            echo '<p><strong>' . __( 'Text Field' ) . ':</strong>' . get_post_meta( $order->id, '_cloudways_text_field', true ) . '</p>';
            echo '<p><strong>' . __( 'Dropdown' ) . ':</strong>' . get_post_meta( $order->id, '_cloudways_dropdown', true ) . '</p>'; ?>
        </div>
        <div class="edit_address">
            <?php woocommerce_wp_text_input( array( 'id' => '_cloudways_text_field', 'label' => __( 'Some field' ), 'wrapper_class' => '_billing_company_field' ) ); ?>
            <?php woocommerce_wp_text_input( array( 'id' => '_cloudways_dropdown', 'label' => __( 'Another field' ), 'wrapper_class' => '_billing_company_field' ) ); ?>
        </div>
    </div>
<?php }
add_action( 'woocommerce_admin_order_data_after_order_details', 'cloudways_display_order_data_in_admin' );

function cloudways_save_extra_details( $post_id, $post ){
    update_post_meta( $post_id, '_cloudways_text_field', wc_clean( $_POST[ '_cloudways_text_field' ] ) );
    update_post_meta( $post_id, '_cloudways_dropdown', wc_clean( $_POST[ '_cloudways_dropdown' ] ) );
}
add_action( 'woocommerce_process_shop_order_meta', 'cloudways_save_extra_details', 45, 2 );

//add data to order emails
function cloudways_email_order_meta_fields( $fields, $sent_to_admin, $order ) {
    $fields['instagram'] = array(
                'label' => __( 'Some field' ),
                'value' => get_post_meta( $order->id, '_cloudways_text_field', true ),
            );
    $fields['licence'] = array(
                'label' => __( 'Another field' ),
                'value' => get_post_meta( $order->id, '_cloudways_dropdown', true ),
            );
    return $fields;
}
add_filter('woocommerce_email_order_meta_fields', 'cloudways_email_order_meta_fields', 10, 3 );

//customize emails
function cloudways_show_email_order_meta( $order, $sent_to_admin, $plain_text ) {
    $cloudways_text_field = get_post_meta( $order->id, '_cloudways_text_field', true );
    $cloudways_dropdown = get_post_meta( $order->id, '_cloudways_dropdown', true );
    if( $plain_text ){
        echo 'The value for some field is ' . $cloudways_text_field . ' while the value of another field is ' . $cloudways_dropdown;
    } else {
        echo '<p>The value for <strong>input text field</strong> is ' . $cloudways_text_field. ' while the value of <strong>drop down</strong> is ' . $cloudways_dropdown . '</p>';
    }
}
add_action('woocommerce_email_customer_details', 'cloudways_show_email_order_meta', 30, 3 );