Add a custom field to the checkout screen

/**

 * Adding a custom field to the checkout screen

 *

 * Covers:

 * 

 * Adding a phone number field to the checkout

 * Making the phone number field required

 * Setting an error when the phone number field is not filled out

 * Storing the phone number into the payment meta

 * Adding the customer's phone number to the "view order details" screen

 * Adding a new {phone} email tag so you can display the phone number in the email notifications (standard purchase receipt or admin notification)

 */

/**

 * Display phone number field at checkout

 * Add more here if you need to

 */

function sumobi_edd_display_checkout_fields() {

?>

    <p id="edd-phone-wrap">

        <label class="edd-label" for="edd-phone">

        	<?php echo 'Phone Number'; ?>

        </label>

        <span class="edd-description">

        	<?php echo 'Enter your phone number so we can get in touch with you.'; ?>

        </span>

        <input class="edd-input" type="text" name="edd_phone" id="edd-phone" placeholder="<?php echo 'Phone Number'; ?>" />

    </p>

    <?php

}

add_action( 'edd_purchase_form_user_info_fields', 'sumobi_edd_display_checkout_fields' );

/**

 * Make phone number required

 * Add more required fields here if you need to

 */

function sumobi_edd_required_checkout_fields( $required_fields ) {

	$required_fields = array(

		'edd_phone' => array(

			'error_id' => 'invalid_phone',

			'error_message' => 'Please enter a valid Phone number'

		),

	);

	return $required_fields;

}

add_filter( 'edd_purchase_form_required_fields', 'sumobi_edd_required_checkout_fields' );

/**

 * Set error if phone number field is empty

 * You can do additional error checking here if required

 */

function sumobi_edd_validate_checkout_fields( $valid_data, $data ) {

    if ( empty( $data['edd_phone'] ) ) {

        edd_set_error( 'invalid_phone', 'Please enter your phone number.' );

    }

}

add_action( 'edd_checkout_error_checks', 'sumobi_edd_validate_checkout_fields', 10, 2 );

/**

 * Store the custom field data into EDD's payment meta

 */

function sumobi_edd_store_custom_fields( $payment_meta ) {

    $payment_meta['phone'] = isset( $_POST['edd_phone'] ) ? sanitize_text_field( $_POST['edd_phone'] ) : '';

    return $payment_meta;

}

add_filter( 'edd_payment_meta', 'sumobi_edd_store_custom_fields');

/**

 * Add the phone number to the "View Order Details" page

 */

function sumobi_edd_view_order_details( $payment_meta, $user_info ) {

	$phone = isset( $payment_meta['phone'] ) ? $payment_meta['phone'] : 'none';

?>

    <div class="column-container">

    	<div class="column">

    		<strong><?php echo 'Phone: '; ?></strong>

    		 <?php echo $phone; ?>	

    	</div>

    </div>

<?php

}

add_action( 'edd_payment_personal_details_list', 'sumobi_edd_view_order_details', 10, 2 );

/**

 * Add a {phone} tag for use in either the purchase receipt email or admin notification emails

 */

edd_add_email_tag( 'phone', 'Customer\'s phone number', 'sumobi_edd_email_tag_phone' );

/**

 * The {phone} email tag

 */

function sumobi_edd_email_tag_phone( $payment_id ) {

	$payment_data = edd_get_payment_meta( $payment_id );

	return $payment_data['phone'];

}