/**
* This function resolves any GUID into a fully qualified URL which can be relocated
* to. It operates in multiple phases:
*
* 1. Check, whether the GUID is already known by NAP. In case we have the corresponding
* node/leaf loaded, use its linking information directly.
* 2. Look if we have a topic, in that case, we get the corresponding NAP node and use
* it to resolve the permalink. If that object is not retrievable, the lookup
* fails.
* 3. We check whether the object in question has a topic as one of its ancestors. If yes,
* that topic and its corresponding component is used to lookup the GUID, which might
* fail.
* 4. As a last resort we have to iterate over all NAP topics to do the resolving.
*
* @param string $guid The GUID to resolve.
* @return string The full HTTP relocation'able URL to the GUID.
*/
function resolve_permalink($guid)
{
// resolves a guid into a fully qualified url, uses some heuristics for that, mainly replaces
// the nap permalink resolver, with the difference that it will be based on the
// components permalink interface code.
$nav = new midcom_helper_nav();
// Step 1: Maybe NAP already knows the topic.
$napobj = $nav->resolve_guid($guid);
if ($napobj) {
return $napobj[MIDCOM_NAV_FULLURL];
}
try {
$object = midcom::get('dbfactory')->get_object_by_guid($guid);
} catch (midcom_error $e) {
debug_add("Failed to resolve the GUID {$guid}, this is most probably an access denied error.", MIDCOM_LOG_ERROR);
debug_add('Last MidCOM error string: ' . $e->getMessage());
return null;
}
$metadata = midcom_helper_metadata::retrieve($object);
if (!$metadata->is_object_visible_onsite()) {
return null;
}
if (is_a($object, 'midcom_db_topic')) {
$napobj = $nav->get_node($object->id);
if (!$napobj) {
debug_add("Failed to retrieve the NAP object for topic {$object->id}.", MIDCOM_LOG_INFO);
return null;
}
return $napobj[MIDCOM_NAV_FULLURL];
}
if (is_a($object, 'midcom_db_attachment')) {
// Faster linking to attachments
$parent = $object->get_parent();
if (is_a($parent, 'midcom_db_topic') && $nav->is_node_in_tree($parent->id, $nav->get_root_node())) {
$napobj = $nav->get_node($parent->id);
return $napobj[MIDCOM_NAV_FULLURL] . $object->name;
} else {
return "{$GLOBALS['midcom_config']['midcom_site_url']}midcom-serveattachmentguid-{$object->guid}/{$object->name}";
}
}
// Ok, unfortunately, this is not an immediate topic. We try to traverse
// upwards in the object chain to find a topic.
$topic = null;
$parent = $object->get_parent();
while ($parent) {
if (is_a($parent, 'midcom_db_topic')) {
// Verify that this topic is within the current sites tree, if it is not,
// we ignore it. This might happen on symlink topics with static & co
// which point to the outside f.x.
if ($nav->is_node_in_tree($parent->id, $nav->get_root_node())) {
$topic = $parent;
break;
}
}
$parent = $parent->get_parent();
}
if ($topic !== null) {
$return_value = $this->_resolve_permalink_in_topic($topic, $guid);
if ($return_value != null) {
return $return_value;
}
}
// Bad, this means a full scan,
// We need to try every topic for the GUID.
$topic_qb = midcom_db_topic::new_query_builder();
$topic_qb->add_constraint('name', '<>', '');
$topic_qb->add_constraint('up', 'INTREE', midcom_core_context::get()->get_key(MIDCOM_CONTEXT_ROOTTOPIC)->id);
$topics = $topic_qb->execute();
foreach ($topics as $topic) {
$result = $this->_resolve_permalink_in_topic($topic, $guid);
if ($result !== null) {
return $result;
}
}
// We were unable to find the GUID
return null;
}
