CKAN is a powerful, open source, open data management platform, used by governments and organizations around the world to make large collections of data accessible, including the UK and US government open data portals.
Today we are very happy and excited to announce the final release of CKAN 2.0. This is the most significant piece of CKAN news since the project began, and represents months of hectic work by the team and other contributors since before the release of version 1.8 last October, and of the 2.0 beta in February. Thank you to the many CKAN users for your patience – we think you’ll agree it’s been worth the wait.
CKAN 2.0 is a significant improvement on 1.x versions for data users, programmers, and publishers. Enormous thanks are due to the many users, data publishers, and others in the data community, who have submitted comments, code contributions and bug reports, and helped to get CKAN to where it is. Thanks also to OKF clients who have supported bespoke work in various areas that has become part of the core code. These include data.gov, the US government open data portal, which will be re-launched using CKAN 2.0 in a few weeks. Let’s look at the main changes in version 2.0. If you are in a hurry to see it in action, head on over to demo.ckan.org, where you can try it out.
CKAN 2.0 introduces a new sleek default design, and easier theming to build custom sites. It has a completely redesigned authorisation system enabling different departments or bodies to control their own workflow. It has more built-in previews, and publishers can add custom previews for their favourite file types. News feeds and activity streams enable users to keep up with changes or new datasets in areas of interest. A new version of the API enables other applications to have full access to all the capabilities of CKAN. And there are many other smaller changes and bug fixes.
Design and theming
The first thing that previous CKAN users notice will be the greatly improved page design. For the first time, CKAN’s look and feel has been carefully designed from the ground up by experienced professionals in web and information design. This has affected not only the visual appearance but many aspects of the information architecture, from the ‘breadcrumb trail’ navigation on each page, to the appearance and position of buttons and links to make their function as transparent as possible.
Under the surface, an even more radical change has affected how pages are themed in CKAN. Themes are implemented using templates, and the old templating system has been replaced with the newer and more flexible Jinja2. This makes it much easier for developers to theme their CKAN instance to fit in with the overall theme or branding of their web presence.
Authorisation and workflow: introducing CKAN ‘Organizations’
Another major change affects how users are authorised to create, publish and update datasets. In CKAN 1.x, authorisation was granted to individual users for each dataset. This could be augmented with a ‘publisher mode’ to provide group-level access to datasets. A greatly expanded version of this mode, called ‘Organizations’, is now the default system of authorisation in CKAN. This is much more in line with how most CKAN sites are actually used.
Organizations make it possible for individual departments, bodies, groups, etc, to publish their own data in CKAN, and to have control over their own publishing workflow. Different users can have different roles within an Organization, with different authorisations. Linked to this is the possibility for each dataset to have different statuses, reflecting their progress through the workflow, and to be public or private. In the default set-up, Organization user roles include Members (who can read the Organization’s private datsets), Editors (who can add, edit and publish datasets) and Admins (who can add and change roles for users).
In addition to the existing image previews and table, graph and map previews for spreadsheet data, CKAN 2.0 includes previews for PDF files (shown below), HTML (in an iframe), and JSON. Additionally there is a new plugin extension point that makes it possible to add custom previews for different data types, as described in this recent blog post.
News feeds and activity streams
CKAN 2.0 provides users with ways to see when new data or changes are made in areas that they are interested in. Users can ‘follow’ datasets, Organizations, or groups (curated collections of datasets). A user’s personalised dashboard includes a news feed showing activity from the followed items – new datasets, revised metadata and changes or additions to dataset resources. If there are entries in your news feed since you last read it, a small flag shows the number of new items, and you can opt to receive notifications of them via e-mail.
Each dataset, Organization etc also has an ‘activity stream’, enabling users to see a summary of its recent history.
Programming with CKAN: meet version 3 of the API
CKAN’s powerful application programming interface (API) makes it possible for other machines and programs to automatically read, search and update datasets. CKAN’s API was previously designed according to REST principles. RESTful APIs are deservedly popular as a way to expose a clean interface to certain views on a collection of data. However, for CKAN we felt it would be better to give applications full access to CKAN’s own internal machinery.
A new version of the API – version 3 – trialled in beta in CKAN 1.8, replaced the REST design with remote procedure calls, enabling applications or programmers to call the same procedures as CKAN’s own code uses to implement its user interface. Anything that is possible via the user interface, and a good deal more, is therefore possible through the API. This proved popular and stable, and so, with minor tweaks, it is now the recommended API. Old versions of the API will continue to be provided for backward compatibility.
Documentation, documentation, documentation
CKAN comes with installation and administration documentation which we try to keep complete and up-to-date. The major changes in the rest of CKAN have thus required a similarly concerted effort on the documentation. It’s great when we hear that others have implemented their own installation of CKAN, something that’s been increasing lately, and we hope to see even more of this. The docs have therefore been overhauled for 2.0. CKAN is a large and complex system to deploy and work on improving the docs continues: version 2.1 will be another step forward. Where people do run into problems, help remains available as usual on the community mailing lists.
… And more
There are many other minor changes and bug fixes in CKAN 2.0. For a full list, see the CKAN changelog.
To install your own CKAN, or to upgrade an existing installation, you can install it as a package on Ubuntu 12.04 or do a source installation. Full installation and configuration instructions are at docs.ckan.org.