How to access the thank you page from the single post?

Question

I have a thank you page on my website and I don't want anyone can access it directly so I use the below code and it working.

add_action('template_redirect', function() {
    // ID of the thank you page
    if (!is_page(947)) { //id of page
        return;
    }

    // coming from the form, so all is fine
    if (wp_get_referer() === get_site_url().'/contact-us/') {
        return;
    }

    // we are on thank you page
    // visitor is not coming from form
    // so redirect to home
    wp_redirect(get_home_url());
    exit;
});

Now, what I am doing, I have one more form on my single post and once the user submits the form then it will redirect to the thank you page but it's not going because I added the above code on my function.php.

So anyone knows how to access the thank you page from the single post?

Answer 1

^{Note: WordPress deliberately misspelled the word 'referer', and thus, so did I..}

If you just want to check if the referer is your contact-us Page or any single Post page, then you can first retrieve the current URL path (i.e. example.com/<this part>/) and then check if the path is exactly contact-us (or whatever is your contact Page's slug), and use get_posts() to find a single post having that path as the slug.

So try this, which worked for me (tested with WordPress 5.6.1):

// Replace this:
if (wp_get_referer() === get_site_url().'/contact-us/') {
    return;
}

// with this:
$path = trim( parse_url( wp_get_referer(), PHP_URL_PATH ), '/' );
// If it's the contact page, don't redirect.
if ( 'contact-us' === $path ) {
    return;
} elseif ( $path ) {
    $posts = get_posts( array(
        'name'           => $path,
        'posts_per_page' => 1,
    ) );
    // If a post with the slug in $path was found, don't redirect.
    if ( ! empty( $posts ) ) {
        return;
    }
}

• But note that the code would only work if your permalink structure (for the default post type) is /%postname%/ — with or without the leading and/or trailing slashes.

And bear in mind that the referer can be easily spoofed, so you might want to consider a more reliable approach like using transients or nonces with a short lifespan.. :)

Answer 2

It might be better to match the thanks page, then try to match the referer and if those conditions don't match, do nothing.

add_action('template_redirect', function() {

    // match based on two condition:
    // current page is "thanks" - which I am guessing is "thanks"
    // and the referer is /contact-us/ - not this is unreliable, as referer might be empty
    if ( 
        is_page('thanks') // is page "thanks"
    ) { 
  
        // referer matches
        if( wp_get_referer() === get_site_url().'/contact-us/' ) {
             
            error_log( 'All good..' );
            return;

        } else {

            // redirect to home
            wp_redirect( get_home_url() );
            exit;

        }

    }

    // nothing to do here, as not thanks page

});