Can I "protect" a page with a form asking for an email address?

Question

I am developing a viewing room for an art gallery. Viewing rooms are pages with content that can only be seen by visitors if they provide their email address to add them to a newsletter. Something like the following site: https://www.davidzwirner.com/viewing-room/james-welling.

I know that pages and posts in WordPress can be password protected, but I don't need this type of protection. Is there any action I can hook to do this? Basically, I need to show a form so visitors can type their email address. Once they do this, they are added to a newsletter (a Mailchimp one, for example), and then the actual page is shown. Also, a cookie must be set so they don't have to provide their email address again to access this page in the future.

Thanks in advance

Answer 1

What about filtering the_content?

function se365701_require_email ( $content ) {
    if ( is_page( 'require_email' ) ) && !isset( htmlspecialchars( $_COOKIE['submitted_email']) ) {
      return $form; // your MailChimp Form Code
    } else{
        return $content;
}
add_filter( 'the_content', 'se365701_require_email' );

Note that your form provide itself may have a cookie or you may need to set it when the form is filled out. You could also perhaps use $_POST[] or $_GET instead. You just need some way of knowing if the form was submitted.