Blog library: changing topic / tags sort order

[aliciahcp]

Currently, the default for the topics module is to list blog topics/tags by alphabetical order. How can I switch this to most used tags? What are other options to sort by?

Current code to sort alphabetically:

<div class="blog-sidebar-topic-filter">
{% post_filter "posts_by_topic" select_blog="default", expand_link_text="see all topics", overrideable=False, list_title="Topics", filter_type="tag", order_by="name", max_links="{{ module.number_of_posts }}", label="Topics" %}
</div>

[alyssamwilie]

If you set order_by to topic it should order them by post count.