How can I make a views attach show items based on taxonomy terms?

With the "node content" display, views_attach will only supply an NID argument. This means that if you want to find nodes that share a taxonomy term, you have to start from the current node. Your View has to look at the current node --> current node's taxonomy terms --> other nodes with those taxonomy terms.

The "Taxonomy: Node" relationship SHOULD do what you want, except that it is broken--but that's an issue for Views itself...

Given the way taxonomy works in Drupal 6, yeah, it doesn't play nicely with Views. I honestly gave up on using taxonomy because the integration was so bad. I know merlin was trying to come up with something better but the taxonomy table structure just makes that very difficult.

Since the issue here is with the Views-Taxonomy integration I'm closing this issue. I would refile over to Views but I'm sure there are enough Views-Taxonomy issues there already. :-)

I needed to implement this as well, and I think I found a decent workaround that doesn't require TOO much custom coding. You need the PHP View Filter module (http://drupal.org/project/viewsphpfilter), then do the following:

1. Enable the filter "Node: Node ID PHP handler" for the view that you wish to use for Node Content.
2. (Hard-ish part) Write the appropriate PHP code!

For example, if I wanted a my node attachment to be a view of any node which shared at least one taxonomy term, I could write something to this effect:

//get the node's nid
$url_arg = arg(1);
$nid = $url_arg;
$nids = array();
$tids = array();

//get taxonomy terms from argument nid
$my_result = db_query("SELECT tid FROM term_node WHERE nid = '%s'", $nid);
while ($my_row = db_fetch_array($my_result)) {
 $tids[] = $my_row['tid'];
}

//get nids that share the same terms
foreach ($tids as $tid) {
 $my_result2 = db_query("SELECT nid FROM term_node WHERE tid = '%s'", $tid);
 while ($my_row2 = db_fetch_array($my_result2)) {
   $nids[] = $my_row2['nid'];
 }
}

return $nids;

Hope that helps!

An alternative way of attaching a contextual block to a node, based on taxonomy term, is to use Similar By Terms module, http://drupal.org/project/similarterms
Remember to filter by content type.

For Views Pages, based on taxonomy term, the Views Attach module works fine!