Dynamic email in CF7 (using custom fields) - php

Question

I'm trying to dynamically update the CF7 to field by replacing the recipient string with a custom post field value, though I can't figure out how to assign the value it's definitely replacing the string as I get an error and if I change email it sends. So it tells me the problem is when I'm trying to get the value.
<?php
function wpcf7_dynamic_email_field($args) {
$dynamic_email = get_post_meta(get_the_ID(), 'dynamic_email', true);
if(!empty($args['recipient'])) {
$args['recipient'] = str_replace('emailtobereplaced#email.com', $dynamic_email["dynamic_email"], $args['recipient']);
return $args;
}
return false;
}
add_filter('wpcf7_mail_components', 'wpcf7_dynamic_email_field');
?>
Can anyone point me in the right direction here? My custom field is called dynamic_email and I need the value

Answer 1

get_the_id() won't return the proper ID because Contact form 7 uses Ajax to perform the send.
You can get the post ID from the submission unit tag. The unit tag is a hidden form field that gets posted with the form and it looks cryptic but it stores information about the post. An example unit tag looks like wpcf7-f235-p27-o1. Using a regex we can get the post id out of the unit tag.
function wpcf7_dynamic_email_field( $args ) {
$dynamic_email = '';
$submission = WPCF7_Submission::get_instance();
$unit_tag = $submission->get_meta( 'unit_tag' );
// get the post ID from the unit tag
if ( $unit_tag && preg_match( '/^wpcf7-f(\d+)-p(\d+)-o(\d+)$/', $unit_tag, $matches ) ) {
$post_id = absint( $matches[2] );
$dynamic_email = get_post_meta( $post_id, 'dynamic_email', true );
}
if ( $dynamic_email ) {
$args['recipient'] = str_replace('emailtobereplaced#email.com', $dynamic_email["dynamic_email"], $args['recipient']);
}
return $args;
}
add_filter( 'wpcf7_mail_components', 'wpcf7_dynamic_email_field' );
Since this is a filter and not an action you always want to return the first parameter that was passed to your callback in this case $args.