resource-and-functions.php

<?php
/**
 * The template for displaying all resource pages
 *
 * Template Name: Resource
 * @package WordPress
 * @subpackage Twenty_Sixteen
 * @since Twenty Sixteen 1.0
 */

get_header(); ?>

<?php while ( have_posts() ) : the_post(); ?>
    <?php if ( has_post_thumbnail() ) { the_post_thumbnail(); } ?>

    <h1>
        <?php echo get_the_title(); ?>
    </h1>

    <article>
        <?php echo get_the_content(); ?>
    </article>

    <form id="resource-form" action="http://www.staticpages.info" method="POST">
        <input type="text" name="first_name" placeholder="First Name" required>
        <input type="text" name="last_name" placeholder="Last Name" required>
        <input type="email" name="email" placeholder="Email" required>
        <input type="text" name="company" placeholder="Company" required>
        <input type="hidden" name="resource_title" value="<?php echo get_the_title(); ?>">

        <!-- Playing it safe with adding a nonce field -->
        <?php wp_nonce_field( 'resource_form', 'resource_form_nonce' ); ?>

        <!-- the ID needed because at the other end of the AJAX call PHP doesn't know the id of the page -->
        <input type="hidden" name="post_id" value="<?php echo the_ID(); ?>">

        <input type="submit" value="Send Me the Resource">
    </form>

    <script>
        jQuery( document ).ready(function( $ ) {
            $('#resource-form').submit(function( event ) {
                var formData = $(this).serialize(); // jQuery's method of aggregating form's data
                var action = '&action=resource_form'; // suffix of "wp_ajax_nopriv" action hook in functions.php

                $.ajax({
                    type: 'POST',
                    url: '/wp-admin/admin-ajax.php', // WordPress's url for AJAX calls, should come as a javascript variable from WordPress admin.
                    data: formData + action,
                    success: function( response ) {

                        // server's response goes here
                        $('#resource-form').replaceWith('<p>' + response.data + '</p>');
                    }
                });

                // prevent form submittion and page refresh.
                event.preventDefault();
            });
        });
    </script>

<?php endwhile; ?>

<?php get_footer(); ?>




<?php

// ########################
// functions.php
// ########################

add_action( 'wp_ajax_resource_form', 'zapier_webhook_request' ); // For logged in users.
add_action( 'wp_ajax_nopriv_resource_form', 'zapier_webhook_request' ); // For all the others.

function zapier_webhook_request() {

    // Checking if the nonce is alright.
    if ( isset( $_POST['resource_form_nonce'] ) &&
            wp_verify_nonce( $_POST['resource_form_nonce'], 'resource_form' ) ) {

        $post_id = intval( $_POST['post_id'] );
        $resource_url = get_post_meta( $post_id, 'resource_url', true );
        $zapier_webhook_url = get_post_meta( $post_id, 'zapier_webhook_url', true );

        // Organazing and sanitize data before sending it to Zapier.
        $payload = array(
            'first_name' => sanitize_text_field( $_POST['first_name'] ),
            'last_name' => sanitize_text_field( $_POST['last_name'] ),
            'email' => sanitize_text_field( $_POST['email'] ),
            'company' => sanitize_text_field( $_POST['company'] ),
            'resource_title' => sanitize_text_field( $_POST['resource_title'] ),
            'resource_url' => sanitize_text_field( $resource_url )
        );

        // Sending the data to Zapier,
        // For wp_remote_post to work PHP cURL extension should be enabled on the server.
        $response = wp_remote_post( $zapier_webhook_url, array( 'body' => $payload ) );

        // Checking for errors and returning a json response to the AJAX call.
        if ( ! is_wp_error( $response ) ) {
            wp_send_json_success('Thanks, now check your email!');
        } else {
            wp_send_json_error('Oops, something went wrong. Try again later.');
        }
    } else {
       wp_send_json_error('Nonce is not right.');
    }

    wp_die();
} ?>