Add ability to return list for wp_list_categories..

[profdeadmeat]

Simply:

The function outputs directly to the page it does not allow any function to use the output.

Impact:

Plugins and templates which used the deprecated list_cats can not use the replacement.

Fix:

Change:

echo apply_filters('list_cats', $output);

To:

$output = apply_filters('list_cats', $output);

if ( $echo ) echo $output;

return $output;

This would make it similar to the functionality in wp_list_pages (and probably elsewhere too). Changes required are minimal.

At the end of wp_list_categories(), change the echo statement to this:

$output = apply_filters('list_cats', $output);
if ( $r['echo'] ) echo $output;
else return $output;

Add this to the $defaults array:

'echo' => 1

And there you go. This will allow an "echo" parameter similar to wp_list_pages() echo parameter.

2.2 is in feature freeze, I believe.

Patch to add echo parameter support to wp_list_categories

Regardless of what version it eventually goes in, here's a quick patch for it.

See also #3567.

(In [6091]) Add echo or return option to wp_list_categories. Props Otto42. fixes #4182