Draft up privacy consent prompt

wp_embed_register_handler('umap', '#^https://umap.openstreetmap.de/[a-z]{2}/map/[^/]*#', 'fscoli_embed_umap');

/*

 * Add privacy protection for embed elements: You have to click a button before the

 * content is loaded.

 * Add privacy protection for embed elements: You have to click a button of a consent prompt

 * before the content is loaded.

 */

function fscoli_protect_embed_privacy($embed_html) {

    return $embed_html;  // TODO Wrap this in the code that displays the button before loading anything

function fscoli_show_embed_privacy_consent_prompt($embed_html) {

    // Extract this from the embed_html string with regular expressions and heuristics

    $width              = null;  // TODO

    $height             = null;  // TODO

    $provider_url       = null;  // TODO

    $provider_domain    = null;  // TODO

    $privacy_policy_url = null;  // TODO

    /* 

     * We use the heredoc syntax (https://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc)

     * to embed a multiline string in this document. Heredocs can be delimited by any string - we chose HTML, but EOT and END

     * are more commonly used options. Funny enough, when we use HTML to delimit the heredoc, at least Visual Studio Code

     * applies HTML syntax highlighting to the string...

     */ 

    $privacy_consent_prompt = <<<HTML

    <div class="privacy-consent-prompt-area" style="width: ${esc_attr(width)}; height: ${esc_attr(height)};">

        <div class="unloaded-content">

            ${esc_html($embed_html)}

        </div>

        <section class="privacy-consent-prompt">

            <button onclick="givePrivacyConsent(this.parentElement)">Inhalt anzeigen</button>

            <p>Dabei werden Daten an <a href="${esc_url(provider_url)}">${esc_html(provider_domain)}</a> (und ggfs. weitere Anbieter) übertragen. Es gilt die <a href="${esc_url(privacy_policy_url)}">dort verlinkte Datenschutzerklärung</a>.</p>

        </section>

    </div>

    <script>

        function givePrivacyConsent(consentPromptArea) {

            consentPromptArea.outerHTML = consentPromptArea.querySelector(".unloaded-content").textContent

        }

    </script>

    HTML;

    return $privacy_consent_prompt;   

}

add_filter('embed_handler_html', 'fscoli_protect_embed_privacy');

add_filter('embed_handler_html', 'fscoli_show_embed_privacy_consent_prompt');

?>