wp_get_object_terms Returns Duplicate Terms

[filosofo]

wp_get_object_terms() accepts multiple objects in its first parameter. If the multiple objects have terms in common, then wp_get_object_terms() returns those terms more than once in the returned array of term data.

Patch makes the array of terms unique.

Any chance of this in for 2.9?

By default, array_unique() compares the contents of the array as a string, fouls it up as you found out..

Did setting the compare to REGULAR help at all? ie. $terms = array_unique($terms, SORT_REGULAR);

The attached patch has a slight issue, {{fields = all_with_object_id}}} will no longer return a the full set of object Id/term id/taxonomy id suite, only the first termid found for each..

Simply adding DISTINCT to the queries seems a better option to me.. More foolproof to let the SQL layer filter out the other rows. see patch.

I've tested the patch very basic, And seems to work in all the cases i can think of.

Before:

$terms = wp_get_object_terms( array(10,12), 'category', array('fields' => 'all_with_object_id') );

var_dump($terms);

array(2) {
  [0]=>
  object(stdClass)#10 (10) {
    ["term_id"]=>
    string(1) "4"
    ["name"]=>
    string(6) "Artist"
    ["slug"]=>
    string(6) "artist"
    ["term_group"]=>
    string(1) "0"
    ["term_taxonomy_id"]=>
    string(1) "4"
    ["taxonomy"]=>
    string(8) "category"
    ["description"]=>
    string(0) ""
    ["parent"]=>
    string(1) "0"
    ["count"]=>
    string(1) "2"
    ["object_id"]=>
    string(2) "10"
  }
  [1]=>
  object(stdClass)#9 (10) {
    ["term_id"]=>
    string(1) "4"
    ["name"]=>
    string(6) "Artist"
    ["slug"]=>
    string(6) "artist"
    ["term_group"]=>
    string(1) "0"
    ["term_taxonomy_id"]=>
    string(1) "4"
    ["taxonomy"]=>
    string(8) "category"
    ["description"]=>
    string(0) ""
    ["parent"]=>
    string(1) "0"
    ["count"]=>
    string(1) "2"
    ["object_id"]=>
    string(2) "12"
  }
}

Note, Object ID in there.

With wp_get_object_terms-unique-results.11003.diff:

$terms = wp_get_object_terms( array(10,12), 'category', array('fields' => 'all_with_object_id') );

var_dump($terms);
 
array(1) {
  [4]=>
  object(stdClass)#9 (10) {
    ["term_id"]=>
    string(1) "4"
    ["name"]=>
    string(6) "Artist"
    ["slug"]=>
    string(6) "artist"
    ["term_group"]=>
    string(1) "0"
    ["term_taxonomy_id"]=>
    string(1) "4"
    ["taxonomy"]=>
    string(8) "category"
    ["description"]=>
    string(0) ""
    ["parent"]=>
    string(1) "0"
    ["count"]=>
    string(1) "2"
    ["object_id"]=>
    string(2) "12"
  }
}

Note, that due to the indexing of the array on $term->term_id in order to filter out duplicates, the 2 have been combined.

It might make sense to have that optional to not change the current behaviour (back-compat), for example I might want to have that dupes instead of not.

In my patch I adopted the premier suggestion and added an additional parameter: select. It might make sense to adopt that to the SQL queries as well.

It's pretty easy to make the terms unique afterwards, once you know there might be duplicates.

Maybe we should just add a notice in the documentation?

It's better than nothing, but not a true solution.

How about this: use DISTINCT to remove duplicate terms, but only when $fields != 'all_with_object_id'.

Related superset of this ticket: ##15675