Wordpress Contact Form Function

wp-contact-form-function.php

<?php

##################################################
## Wordpress Contact Form Function
##################################################
function html_form_code() {

    echo '<form action="' . esc_url( $_SERVER['REQUEST_URI'] ) . '" method="post">';
    echo '<p class="form-group">';
    echo '<input required aria-label="Your Name (required)" placeholder="Your Name (required)" type="text" name="cf-name" pattern="[a-zA-Z0-9 ]+" value="' . ( isset( $_POST["cf-name"] ) ? esc_attr( $_POST["cf-name"] ) : '' ) . '" size="40" />';
    echo '</p>';
    echo '<p class="form-group">';
    echo '<input required aria-label="Your Email (required)" placeholder="Your Email (required)" type="email" name="cf-email" value="' . ( isset( $_POST["cf-email"] ) ? esc_attr( $_POST["cf-email"] ) : '' ) . '" size="40" />';
    echo '</p>';
    echo '<p class="form-group">';
    echo '<input required aria-label="Contact Number (required)" placeholder="Contact Number (required)" type="text" name="cf-number" pattern="[a-zA-Z0-9 ]+" value="' . ( isset( $_POST["cf-name"] ) ? esc_attr( $_POST["cf-name"] ) : '' ) . '" size="40" />';
    echo '</p>';
    echo '<p class="form-group">';
    echo '<input required aria-label="Subject (required)" placeholder="Subject (required)" type="text" name="cf-subject" pattern="[a-zA-Z ]+" value="' . ( isset( $_POST["cf-subject"] ) ? esc_attr( $_POST["cf-subject"] ) : '' ) . '" size="40" />';
    echo '</p>';
    echo '<p class="form-group">';
    echo '<textarea required name="cf-message">' . ( isset( $_POST["cf-message"] ) ? esc_attr( $_POST["cf-message"] ) : '' ) . '</textarea>';
    echo '</p>';
    echo '<p class="form-group"><input aria-label="Send" type="submit" name="cf-submitted" value="Send"/></p>';
    echo '</form>';

}

function deliver_mail() {

    // if the submit button is clicked, send the email
    if ( isset( $_POST['cf-submitted'] ) ) {

        // sanitize form values
        $name    = sanitize_text_field( $_POST["cf-name"] );
        $email   = sanitize_email( $_POST["cf-email"] );
        $phone   = sanitize_text_field( $_POST["cf-number"] );
        $subject = sanitize_text_field( $_POST["cf-subject"] );
        $message2 = esc_textarea( $_POST["cf-message"] );
        $message = "From: $name <$email>" . "\r\n" . "Phone: <$phone>" . "\r\n" . $message2 ;

        // get the blog administrator's email address
        $to = 'service@site.com';

        $headers = "From: $name <$email>" . "\r\n";

        // If email has been process for sending, display a success message
        if ( wp_mail( $to, $subject, $message, $headers ) ) {
            echo '<div class="alert">';
            echo '<span class="closebtn" onclick="this.parentElement.style.display=\'none\';">&times;</span>';
            echo '<p>Thanks for contacting me, expect a response soon.</p>';
            echo '</div>';
        } else {
            echo '<div class="alert dangerous">';
            echo '<span class="closebtn" onclick="this.parentElement.style.display=\'none\';">&times;</span>';
            echo 'An unexpected error occurred';
            echo '</div>';
        }
    }
}

function cf_shortcode() {
    ob_start();
    deliver_mail();
    html_form_code();

    return ob_get_clean();
}

add_shortcode( 'contact_form', 'cf_shortcode' );