This page explains the necessary steps to use OntoWiki with OpenLink Virtuoso. Especially, it covers the following topics:

  • Install Virtuoso
  • Download and install OntoWiki
  • Configure OntoWiki to use Virtuoso

Overview

This is the basic procedure. For details see below.

  • download and install homebrew
  • run brew update to update the dependencies
  • there have to be installed PHP with ODBC support brew install php56 --with-unixodbc
  • execute brew install virtuoso to get installed Virtuoso
  • Set up ODBC
  • Check out the OntoWiki source code
  • Set up OntoWiki to be used with Virtuoso.

Setting up ODBC

Database connection to Virtuoso happens through ODBC. ODBC is configured by two files, odbc.ini and odbcinst.ini. On Mac OS X systems they can be found under /Library/ODBC. In case they don’t exist, create them.

Add the following lines to the odbcinst.ini file:

[virtuoso-odbc]
Driver = <prefix>/lib/virtodbc.so

Add the following lines to the odbc.ini file:

[ODBC Data Sources]
VOS = Virtuoso

[VOS]
Driver = virtuoso-odbc
Description = Virtuoso Open-Source Edition
Address = localhost:1111

Now make sure, PHP can connect to Virtuoso via ODBC.

Newer versions of OntoWiki come with a script to test the connectivity to Virtuoso. Just type the following on the command-line while in the OntoWiki root directory:

make odbctest

If this gives you an error like

make: *** No rule to make target `odbctest'.  Stop.

try the following to test the connection: Create a file called odbctest.php in your webroot with the following PHP code in it:

<?php
$conn   = odbc_connect('VOS', 'dba', 'dba');
echo odbc_errormsg();
$query  = 'SELECT DISTINCT ?g WHERE {GRAPH ?g {?s ?p ?o.}}';
$result = odbc_exec($conn, 'CALL DB.DBA.SPARQL_EVAL(\'' . $query . '\', NULL, 0)');
?>
<ul>
<?php while (odbc_fetch_row($result)): ?>
    <li><?php echo odbc_result($result, 1) ?></li>
<?php endwhile; ?>
</ul>

Execute it by clicking on this link: http://localhost/odbctest.php. You should see a list of graphs stored in your Virtuoso RDF store. On a vanilla Virtuoso installation this list should include the following two graphs:

  • http://www.openlinksw.com/schemas/virtrdf#
  • http://localhost:8890/DAV

If you see this list and no error messages along the way, go ahead configuring OntoWiki.

Configuring OntoWiki

Perform the following steps to set up OntoWiki:

  • Copy config.ini.dist to config.ini and open it in a text editor
  • Under [private], set the following options:

    store.backend = virtuoso store.virtuoso.dsn = VOS store.virtuoso.username = dba store.virtuoso.password = dba

  • Optional 1: to enable OntoWiki’s debug mode, add the line debug = yes
  • Optional 2: If you didn’t change any other config option, create the following directories relative to your OntoWiki installation and make them writable to the web-server user: /cache, /logs, /uploads.
Tags: ontowiki