How to submit the form in WordPress

Today, We will learn How to submit the form in WordPress. WordPress has default a generic handler to deal with all forms in admin-post.php. When we submit the form on our WordPress website, we need to include a hidden field in a form called action.

Example

index.php

<?php 

$html = "<form method='post' action='".get_admin_url()."admin-post.php'>
    <input type='hidden' name='action' value='submit-form'/>
    <input type='hidden' name='redirect_url' value='".$_SERVER['REQUEST_URI']."'/><fieldset>
        <div class='name field text_field' id='field-name'>
            <label class='field-label'>Your Name*</label>
            <input type='text' name='name' required placeholder='Your Name*' />
        </div>
        <div class='phone field text_field' id='field-phone'>
            <label class='field-label'>Phone</label>
            <input type='text' name='phone' required class='plain-phone' placeholder='Phone' />
        </div>
        <div class='email field email_field' id='field-email'>
            <label class='field-label'>Email*</label>
            <input type='email' name='email' required placeholder='Email*' />
        </div>
        <div class='url field text_field' id='field-url'>
            <label class='field-label'>URL</label>
            <input type='text' name='url' placeholder='URL' />
        </div>
        <div class='message field text_area' id='field-message'>
            <label class='field-label'>Message</label>
            <textarea name='message' placeholder='Message'></textarea>
        </div>
    </fieldset>
    <div class='footer'>
        <input type='submit' name='submit' value='Send Message' />
    </div>
</form>";

return $html;

functions.php

<?php 
add_action('admin_post_registration-form', '_handle_form_action'); #If the user is logged in
add_action('admin_post_nopriv_registration-form', '_handle_form_action'); #If the user in not logged
function _handle_form_action(){
    global $wpdb;
    session_start();

    $name = $_POST['name'];
    $phone = $_POST['phone'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $redirect_url = $_POST['redirect_url'];
	$admin_email = 'info@devnote.in';

	$headers = "MIME-Version: 1.0\r\n";
    $headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";

    $data = "<b>Name</b>: $name \r\n <b>Phone</b>: $phone \r\n <b>Email</b>: $email \r\n <b>Message</b>: $message";

    $mail = wp_mail($admin_email, "Your subject here!", $data);
    if($mail) {
        wp_redirect(home_url('/').$redirect_url.'/?status=1');
    } else {
        wp_redirect(home_url('/').$redirect_url.'/?status=0');
    }
    die();
}