How do I redirect anonymous users to a login page?

The forum module uses the "access content" permission to determine whether or not content should be shown.

If you want anonymous users to be able to read regular nodes, but not access the forums, then you need to set up a different access permission for the forums. The following might work:

In forum.module around line 57, change:

  return array('create forum topics', 'edit own forum topics', 'administer forums');

to add the permission "access forum content"

  return array('create forum topics', 'edit own forum topics', 'administer forums', 'access forum content');

now you need to change the permission associated with the forum/* request. On lines 417 - 420, change:

    $items[] = array('path' => 'forum', 'title' => t('forums'),
      'callback' => 'forum_page',
      'access' => user_access('access content'),
      'type' => MENU_SUGGESTED_ITEM);

to the new access permission created above:

    $items[] = array('path' => 'forum', 'title' => t('forums'),
      'callback' => 'forum_page',
      'access' => user_access('access forum content'),
      'type' => MENU_SUGGESTED_ITEM);

Don't use forums myself, so I couldn't test it.

(BTW, on mine I have to disable then re-enable the module in order for the access and menu (forum/*) changes to be picked up.

- Corey

True, this doesn't set a destination. I'll come up with another snippet (and test it) soon. It shouldn't be too hard.

--
http://www.ppmaf.org

Ok, here's some code to do what we need. Insert it into a PHP input filter page.

Version one: immediate drupal_goto

drupal_set_message("Access Denied: Please Login");
$dest = drupal_get_destination();
drupal_goto('user/login', $dest); // this remembers where the user is coming from

Version two: use a meta refresh after 10 seconds

$dest = drupal_get_destination();
$url = "http://www.youdomain.com/user/login?destination=$dest"
drupal_set_html_head('<meta http-equiv="refresh" content="10;URL=' . $url . '">');

The advantage of version 2 is that you have 10 seconds during to alert the user that they are going somewhere else. You can wrap the PHP in standard HTML to give more information.

Both versions should return the user to the requested page after login.

Beware, there is a good likelihood you will find yourself in an endless loop of redirects after you submit the node with this PHP in it. This is because you are already logged in.

If fact, you may want to use version 3: the safe version:

global $user
if ($user->uid) { // this user is already logged in
print "Access Denied: You do not have access to this page.";
} else {
drupal_set_message("Access Denied: Please Login");
$dest = drupal_get_destination();
drupal_goto('user/login', $dest); // this remembers where the user is coming from
}

This is somewhat tested code. Caveat emptor.
--
http://www.ppmaf.org

Hopefully someone else finds this helpful... My "/access-denied" page looks like this:

<?php
global $user;

if ($user->uid) { 

print $user->name; ?>,
<p>We apologize, but you do not have permission to access this page.</p>
<p>If you feel that you have received this message in error, please <a href="/contact">contact us</a> with specific details so that we may review your access to our web site.</p>
<p>Thank You</p>
<?php } 

else { 

$dest = drupal_get_destination();

?><p>The page you requested is available to members only...</p>
<div class="links">&raquo; <a href="/user/login?<?php print $dest ?>">login</a> or <a href="/user/register?<?php print $dest ?>">register</a> to view this page</div>
<?php } ?>

The code provided earlier that does a drupal_goto() was causing me trouble, so I modified it a bit to show different messages based on whether the user is logged in, or unauthenticated. The $dest portion of the code takes the user to the destination page after they have logged in.

Hello,

I tested this code in Drupal 5.2 and it just does a loop of redirection when drupal_goto function is invoked.
Did anyone find a fix for this or maybe there's another way to acheive this now ? I think redirecting directly with header() isn't really a good idea, I guess it will mess up the session :S