Connect Your WordPress Site to Mailchimp Easily

Code

<?php
// Function to integrate Mailchimp with WordPress using API Key
function wp_dudecom_mailchimp_integration() {
    // Add your Mailchimp API Key here
    $api_key = 'your_mailchimp_api_key';
    // Add your Mailchimp List ID here
    $list_id = 'your_mailchimp_list_id';

    // Check if the API Key and List ID are set
    if (empty($api_key) || empty($list_id)) {
        return;
    }

    // Enqueue jQuery for AJAX
    wp_enqueue_script('jquery');

    // Localize script to pass data to JavaScript
    wp_localize_script('jquery', 'wp_dudecom_mailchimp', array(
        'ajax_url' => admin_url('admin-ajax.php'),
        'nonce' => wp_create_nonce('wp_dudecom_mailchimp_nonce')
    ));

    // Add AJAX action for logged-in users
    add_action('wp_ajax_wp_dudecom_subscribe', 'wp_dudecom_subscribe_to_mailchimp');
    // Add AJAX action for non-logged-in users
    add_action('wp_ajax_nopriv_wp_dudecom_subscribe', 'wp_dudecom_subscribe_to_mailchimp');
}
add_action('wp_enqueue_scripts', 'wp_dudecom_mailchimp_integration');

// Function to handle subscription to Mailchimp
function wp_dudecom_subscribe_to_mailchimp() {
    // Verify nonce for security
    check_ajax_referer('wp_dudecom_mailchimp_nonce', 'security');

    // Get email from AJAX request
    $email = isset($_POST['email']) ? sanitize_email($_POST['email']) : '';

    if (!is_email($email)) {
        wp_send_json_error('Invalid email address.');
    }

    // Mailchimp API URL
    $api_url = 'https://<dc>.api.mailchimp.com/3.0/lists/' . $list_id . '/members/';

    // Prepare data for Mailchimp API
    $data = array(
        'email_address' => $email,
        'status' => 'subscribed'
    );

    // Setup request headers
    $headers = array(
        'Authorization' => 'Basic ' . base64_encode('user:' . $api_key),
        'Content-Type' => 'application/json'
    );

    // Make API request to Mailchimp
    $response = wp_remote_post($api_url, array(
        'headers' => $headers,
        'body' => json_encode($data)
    ));

    // Check for errors in API response
    if (is_wp_error($response)) {
        wp_send_json_error('Failed to subscribe. Please try again.');
    }

    // Decode response body
    $response_body = json_decode(wp_remote_retrieve_body($response), true);

    if (isset($response_body['status']) && $response_body['status'] == 'subscribed') {
        wp_send_json_success('Successfully subscribed!');
    } else {
        wp_send_json_error('Failed to subscribe. Please try again.');
    }
}

// Shortcode to display subscription form
function wp_dudecom_mailchimp_form_shortcode() {
    ob_start();
    ?>
    <form id="wp-dudecom-mailchimp-form">
        <input type="email" name="email" placeholder="Enter your email" required>
        <button type="submit">Subscribe</button>
    </form>
    <div id="wp-dudecom-mailchimp-response"></div>
    <script type="text/javascript">
        jQuery(document).ready(function($) {
            $('#wp-dudecom-mailchimp-form').on('submit', function(e) {
                e.preventDefault();
                var email = $(this).find('input[name="email"]').val();
                $.ajax({
                    url: wp_dudecom_mailchimp.ajax_url,
                    type: 'POST',
                    data: {
                        action: 'wp_dudecom_subscribe',
                        email: email,
                        security: wp_dudecom_mailchimp.nonce
                    },
                    success: function(response) {
                        $('#wp-dudecom-mailchimp-response').html(response.data);
                    }
                });
            });
        });
    </script>
    <?php
    return ob_get_clean();
}
add_shortcode('wp_dudecom_mailchimp_form', 'wp_dudecom_mailchimp_form_shortcode');
?>