The "field api name" key should only be set for Field API fields, not all properties

Ah, OK, then that explains #1215526: Add support for the "Bundle" dependency plugin, right? Should have read the issues in the other order …

Is it 'field api name' or 'facet api name'? In case of the former, this seems to be fixed.

Or, should this only be set for Field API fields? We currently set it for all properties … This will probably mess up the dependencies, right?

To reiterate, the "field api name" should not be set for properties. Do you see a need for a "field api property" or something similar?

As long as the Facet API has no use for it (which doesn't seem to have), no, I don't.

OK, then we have to differentiate between the two in the hook …
I'll see what we can do there.

OK, this is now fixed, sort of. There is a simple way of telling that via an entity metadata wrapper (provided by the Entity API). The code for getting the wrapper isn't that easy, however:

// Find out whether this property is a Field API field.
$wrapper = $index->entityWrapper();
foreach (explode(':', $key) as $part) {
  if (!isset($wrapper->$part)) {
    $wrapper = NULL;
    break;
  }
  $wrapper = $wrapper->$part;
  while (($info = $wrapper->info()) && search_api_is_list_type($info['type'])) {
    $wrapper = $wrapper[0];
  }
}
if ($wrapper && !empty($info['field'])) {
  $facet_info[$key]['field api name'] = $key;
}

Well, it works. It's just executed every time the hook is called, for all indexed fields, which isn't really optimal. Is there any way of caching these values (I know, that was already asked) or would we have to implement that ourselves? In the latter case, we should definitely do that.

I also think we should get rid of the $field_callbacks variable in the hook and just set always set a few values (type, entity type, …) and let search_api_facet_map_callback() directly figure out the rest.

Let's just remember there there are two hard things in computer science: cache invalidation, naming things, and off-by-one errors.

Hehe, gotta remember that one. :D

However, in the previous facet solution I also cached the data (directly on the facet objects) and didn't really have a problem there. But as we already need the information in the hook, where we have no facet objects yet, this isn't really possible here. We'd have to keep a cache of all indexed Field API fields for each index, or something like that.

But for other data, would there be a good way of storing/caching such information in the facet objects?

Ah, come to think of it – most of the code is unnecessary anyways, as we don't have to check this at all for nested fields. Changing this …