Terms of service for anonymous posts in Question2Answer

Question

I want to allow anonymous posts in my Question2Answer forum. This can be configured under Admin → Permissions by giving the "Asking questions" and "Answering questions" privileges to "Anybody."

However, I also want the terms of service for my forum to apply to anonymous posts as well, meaning that an anonymous user would be required to accept those terms when posting a question or answer. The available options I've seen so far don't really do what I want:

• Enable a "Terms & Conditions" checkbox on the registration form (under Admin → Users): this only applies to user registration, not to posting questions or answers.
• Enable custom messages on the ask and answer forms (under Admin → Posting): this shows the message every time the form is displayed, not just for anonymous users.

I realized that with a captcha enabled there is a specific message displayed only when posting a question or answer as an anonymous user, so I guess my best option is to patch that message.

Answer 1

A quick search through the Question2Answer code showed that the message was defined via this line in qa-include/app/captcha.php:

$notehtml = qa_insert_login_links(qa_lang_html('misc/captcha_login_fix'));

so the simplest way would've been to just patch the additional message text into that line:

$notehtml = "My custom message. " . qa_insert_login_links(qa_lang_html('misc/captcha_login_fix'));

However, since I defined my terms and conditions in a custom page (Admin → Pages) and I didn't want to hard-code the link to that page, I decided to dig a little deeper.

The function qa_lang_html() is looking up message identifiers and returns them as HTML fragments. The message identified by the string "misc/captcha_login_fix" comes from a map data structure defined in the file qa-include/lang/qa-lang-misc.php.

'captcha_login_fix' => 'To avoid this verification in future, please ^1log in^2 or ^3register^4.',

The function qa_insert_login_links() then transforms the text between the markers ^1/^2 and ^3/^4 respectively into links.

In order to get my desired result, I added another lookup term "captcha_terms_fix" to qa-lang-misc.php and extended qa_insert_login_links() (in the file qa-include/app/format.php) to replace my additional markers ^7/^8 with the correct link.

function qa_insert_login_links($htmlmessage, $topage = null, $params = null)
{
  require_once QA_INCLUDE_DIR . 'app/users.php';

  $userlinks = qa_get_login_links(qa_path_to_root(), isset($topage) ? qa_path($topage, $params, '') : null);

  return strtr(
    $htmlmessage,

    array(
      '^1' => empty($userlinks['login']) ? '' : '<a href="' . qa_html($userlinks['login']) . '">',
      '^2' => empty($userlinks['login']) ? '' : '</a>',
      '^3' => empty($userlinks['register']) ? '' : '<a href="' . qa_html($userlinks['register']) . '">',
      '^4' => empty($userlinks['register']) ? '' : '</a>',
      '^5' => empty($userlinks['confirm']) ? '' : '<a href="' . qa_html($userlinks['confirm']) . '">',
      '^6' => empty($userlinks['confirm']) ? '' : '</a>',
      '^7' => empty($userlinks['terms']) ? '' : '<a href="' . qa_html($userlinks['terms']) . '">',
      '^8' => empty($userlinks['terms']) ? '' : '</a>',
    )    
  );
}

For that to work I had to also patch the function qa_get_login_links() in qa-include/app/user.php to produce the correct page reference.

function qa_get_login_links($rooturl, $tourl)
{
  return array(
    'login' => qa_path('login', isset($tourl) ? array('to' => $tourl) : null, $rooturl),
    'register' => qa_path('register', isset($tourl) ? array('to' => $tourl) : null, $rooturl),
    'confirm' => qa_path('confirm', null, $rooturl),
    'logout' => qa_path('logout', null, $rooturl),
    'terms' => qa_path('terms-and-conditions', null, $rooturl),
  );   
}

And because my terms and conditions are defined in a custom page I wanted the additional message (and link) only displayed if that page actually exists. So I added a conditional that checks if the page slug is defined in the database, and prepends the message only if it is.

$notehtml = qa_insert_login_links(qa_lang_html('misc/captcha_login_fix'));
if (qa_db_num_rows(qa_db_query_sub('SELECT tags FROM ^pages WHERE tags LIKE "%terms-and-conditions%"')) > 0) {
  $notehtml = qa_insert_login_links(qa_lang_html('misc/captcha_terms_fix')) . '<br/>' . $notehtml;
}

With those modifications in place, my forum now displays an additional message

By submitting this post you agree to our Terms & Conditions.

along with the captcha for anonymous questions and answers.

If you want this too, a patch for Question2Answer 1.8.4 can be downloaded here.