wp_mail - using a custom field value for $to

Question

I'm trying to pass a custom field value to my functions.php file. I want to replace:

$to = get_bloginfo( 'admin_email' );

to something along the lines of:

$to = get_custom_field('sendto', TRUE);

So the user will have a recipients field on their post (custom post type) that they can add email addresses to, then when the post is published, those users will receive the notification as well.

Thank You for any help.

Answer 1

I'm going to assume the folks receiving these emails has gone through the whole two step opt in procedure or they have given their consent in some other way.

There is an action called {$status}_{$post_type} that fires whenever a post is transitioned from one status to another. So when a post is published, the hook publish_post fires; when a custom post type is published the hook publish_the_custom_post_type is fired.

You can hook into this, grab whatever post meta you need, and send emails.

Example:

<?php
// replace 'publish_post' with 'publish_your_post_type'
add_action('publish_post', 'wpse52135_transition', 10, 2);
/*
 * When a post moves from 'draft' to 'publish, send an email
 *
 * @uses get_post_meta
 * @uses update_post_mtea
 * @uses wp_mail
 */
function wpse52135_transition($post_id, $post)
{
    // store the fact that we sent an email in a custom field if that
    // field is present, don't resend
    if(get_post_meta($post_id, '_wpse52135_sent_mail', true))
        return;

    $email = get_post_meta($post_id, 'wpse52135_email', true);

    // No email?  bail.
    if(!$email || !is_email($email)) return;

    // email subject
    $subject = sprintf(
        __('New Post: %s', 'wpse52135'),
        esc_attr(strip_tags($post->post_title))
    );

    // email body
    $msg = sprintf(
        __("Check out our new post: %s\n\n%s", 'wpse52135'),
        esc_attr(strip_tags($post->post_title)),
        get_permalink($post)
    );

    // send the email
    wp_mail(
        $email,
        $subject,
        $msg
    );

    update_post_meta($post_id, '_wpse52135_sent_mail', true);
}

As a plugin.