HTML净化器 - 允许链接？

Question

The site is 404'ing so I can't search there. I've tried looking at the docs but it isn't really clear where I might find it. I have made a config with the list of tags I want to allow and included <a> but HTML Purifier removes the href. What do I need to add to the config to allow the href as it is in the default settings of HTML Purifier?

-edit-

This is what I have now:

$config = HTMLPurifier_Config::createDefault();
    $config->set('HTML.AllowedAttributes', 'a.href');
    $config->set('HTML.Allowed', 'various tags');
    $config->set("HTML.Nofollow", true);
    $config->set('CSS.AllowedProperties', '');

Answer 1

Adding $config->set('HTML.AllowedAttributes', 'a.href'); did the trick. However, I would like to hear Edward Yang's thoughts on the matter as he believes it shouldn't be necessary according to his reply.