These CKAN Versions are exactely matched:

• 2.10.0
• 2.10.1
• 2.10.2
• 2.10.3
• 2.10.4
• 2.10.5
• 2.10.6
• 2.10.7
• 2.10.8
• 2.10.9
• 2.11.0
• 2.11.1
• 2.11.2
• 2.11.3
• 2.11.4
• 2.12.0
• 2.9.0
• 2.9.0a
• 2.9.1
• 2.9.10
• 2.9.11
• 2.9.13
• 2.9.2
• 2.9.3
• 2.9.4
• 2.9.5
• 2.9.6
• 2.9.7
• 2.9.8
• 2.9.9

ckanext-topics

Topics and subtopics for classifying datasets in CKAN. Tested for CKAN 2.7.2

Features

This extension provides mechanisms for classifying your datasets in a hierarchy of topics and subtopics. This topics will appear under the Additional info of the dataset:

Topics and subtopics can be assigned to a datasets in its edit page. The available subtopics will be filtered by the selected topic:

Then you can filter search results by a specific topic or subtopic:

Sysadmins can view the complete list of topics and edit them:

Reordering of topics and subtopics is available, but is a bit tedious to do (see Limitations and tradeoffs)

Limitations and tradeoffs

When we started the implementation of this features, we had two possible approaches:

1. Create a new model to support topics and subtopics, with the associated complexity of managing database migrations, taking care of the faceted search etc.
2. Adapt existing CKAN features for this purpose. In this case Tag Vocabularies

We opted for 2, which had the following advantages and disadvantages:

Advantages

• We didn’t have to bother about adding a new model to CKAN, creating its database table, indexing this new model in Solr etc.
• Faceted search was pretty easy to implement.

Disadvantages

The Tag Vocabularies feature is not prepared to support making a hierarchy of them, nor ordering. We have two tag vocabularies, one for topics and other for subtopics:

“` ckan_default=# select * from vocabulary; id | name ————————————–+—————— 69f6965b-5fb1-4736-b4