Although Moriarty is a general purpose library for building applications with the Talis Platform (and tried and tested in Talis Prism and Talis Aspire) one of the most common uses is simply to provide a browsable interface for linked data held in a Talis Platform store. Typically these scripts take the URI sent by the web browser and use a SPARQL query or the Talis Platform’s describe service to fetch linked data about that URI. They then style that as HTML or send it directly back as RDF. There are a series of technical details they all need to deal with: 303 redirects, content negotiation, converting RDF to HTML etc.

I’ve worked on more comprehensive libraries (e.g. Paget) to manage this kind of publishing but I thought the simple case of fetching and styling the data would make a good example of how to use Moriarty. I spent a bit of time this afternoon putting an example script together based on several I’ve written in the past. You can find the result in the dataspace subdirectory of the examples folder. That subdirectory contains four files:

• dataspace.php — this is the example script. It contains the logic to fetch the relevant description, handle content negotiation of the best output format and styling the result appropriately. It’s not designed to be called directly, but to be included from a configuration file…
• index.php — this is an example configuration file. It is designed to be dropped into a web server directory and then intercept all requests beginning with that URI. It contains the configuration describing which Talis Platform store to use, where cache files can be written and where to find Moriarty and ARC2. The last thing it does is to load dataspace.php which then handles the browser request.
• sample.htaccess — this is a sample .htaccess file for Apache webservers. It redirects all requests via index.php.
• plain.tmpl.html — this is the default template used to render the HTML views. This can be overridden in the configuration.

Using the example script is simple: just copy index.php to the root directory of your linked data space. If you’re using Apache then you need to copy sample.htaccess into the same directory and rename it to .htaccess. Edit index.php so it refers to your store and your URIs and that’s it! You can see it in action with the default template on my own linked data space.

About Moriarty… Moriarty is a simple PHP library for accessing the Talis Platform. It follows the Platform API very closely and wraps up many common tasks into convenient classes while remaining very lightweight. It also provides some simple RDF classes that are based on the excellent ARC2 class library. Moriarty is being developed by small community of developers and is in continual beta, subject to a slow stream of updates. You can read more about Moriarty on the n² wiki or visit its Google Code project