Custom Ontology (module for Omeka S)

New versions of this module and support for Omeka S version 3.0 and above are available on GitLab, which seems to respect users and privacy better than the previous repository.

Custom Ontology is a module for Omeka S that allows to create specific classes and properties to describe resources when no standard ontologies are available, in particular on LOV, schema.org, W3C, and in many other places. It is useful to manage internal properties, or for researchers who are creating new data. The properties and classes are available via the standard api of Omeka S too, like any other ontology.

In fact, this module is a replacement of an existing feature on Omeka Classic, where it was allowed to edit and create item types, equivalent of resource classes and resource templates, and to create new elements, equivalent of properties. In Omeka S, in order to share data and to follow the standards of the semantic web, this feature was not ported.

Note that it is always recommended to search and use existing ontologies first, because it will be simpler to share data and to link them semantically. If the properties are known only by you and are not described anywhere, it will be hard to match them and to make relations with other.

This module avoids to create a specific rdf vocabularies, turtle or n3 files too, so anybody can use Omeka S like wished, with any documents or resources.

Installation

See general end user documentation for installing a module.

• From the zip

Download the last release CustomOntology.zip from the list of releases and uncompress it in the modules directory.

• From the source and for development

If the module was installed from the source, rename the name of the folder of the module to CustomOntology.

• For test

The module includes a unit, functional and integration test suite. It requires the module Common. Run it from the root of Omeka:

vendor/bin/phpunit -c modules/CustomOntology/phpunit.xml --testdox

Usage

The module adds a button in the header of the vocabulary page and a direct access in the left sidebar.

Simply click on it and create your ontology, your resources classes or your properties following the instructions.

The three parts of the form are independent: they can be used together to create a new ontology with its terms, or separately to add new classes or properties to an existing ontology.

• The ontology requires a namespace uri, a prefix and a label. The namespace uri must end with / or #. The prefix must be lowercase, start with a letter and contain only letters and digits. The prefixes reserved by Omeka (o, time, cnt) are not allowed.
• Classes and properties are entered one by row, as term, label, comment. The comment is optional. The local name of a class starts with an uppercase letter (myprefix:MyClass), the one of a property with a lowercase letter (myprefix:myProperty). It may contain letters, digits, - and _.
• A term can be added only to the new ontology or to an existing one, except the default Dublin Core vocabularies, for standardization purpose.
• The existing terms are skipped, so a full list can be pasted again. On the contrary, any other error prevents the whole import, so nothing is imported partially.

Once the form is filled, import it directly via the Submit button, or get the turtle file without saving anything via the button Get turtle (no save).

For example, to create a new ontology for a site available at https://example.org, fill the form with:

Namespace uri: https://example.org/ns/demo/
Prefix: demo
Label: Demonstration vocabulary
Comment: A sample vocabulary.

Classes:

demo:Book, Book, A published or written work.
demo:Article, Article, A written piece published in a larger work.

Properties:

demo:author, Author, The person or the organization responsible for the work.
demo:pageCount, Page count

You can add new classes and properties into previously imported ontologies, but you cannot update existing ones from the form. Nevertheless, you still can use the turtle file to upgrade the vocabulary later, like for any other vocabularies, at the core admin page admin/vocabulary. Note that an update via a turtle file adds new terms and updates labels and comments, but it never removes nor renames an existing term.

The unused terms of the custom ontologies can be deleted from the page of the vocabularies, via the icon "Delete unused terms". A term is used when it is set in a resource (class or value), in a resource template, in a setting (global, site or user), in a site (navigation, item pool and page blocks) or in a search config (modules Advanced Search and Search Solr), so it cannot be deleted. The term is searched by name ("prefix:localName") and by id in the queries and in the json data ("property[0][property]=12", "resource_class_id[]=5") or as value of a setting whose name contains "property". The terms of the vocabularies that are not managed by the module cannot be deleted.

When the custom ontologies are named as proposed (Omeka url + /ns/prefix), they will be publicly listed at https://example.org/ns and available as turtle and other rdf formats (json-ld, rdf/xml, ntriples, Notation3), at their namespace uri, and as a web page at https://example.org/ns/{prefix}?format=html. Content negotiation is managed anyway, so the content type accepted in the request will be used if not specified by the url query.

TODO

• [ ] Add support of version in namespace url.
• [ ] Add edition of terms and labels directly on the page vocabulary, with a main edit button and some js (see module Folksonomy).

Warning

Use it at your own risk.

It’s always recommended to backup your files and your databases and to check your archives regularly so you can roll back if needed.

Troubleshooting

See online issues on the module issues page on GitLab.

License

This module is published under the CeCILL v2.1 license, compatible with GNU/GPL and approved by FSF and OSI.

In consideration of access to the source code and the rights to copy, modify and redistribute granted by the license, users are provided only with a limited warranty and the software’s author, the holder of the economic rights, and the successive licensors only have limited liability.

In this respect, the risks associated with loading, using, modifying and/or developing or reproducing the software by the user are brought to the user’s attention, given its Free Software status, which may make it complicated to use, with the result that its use is reserved for developers and experienced professionals having in-depth computer knowledge. Users are therefore encouraged to load and test the suitability of the software as regards their requirements in conditions enabling the security of their systems and/or data to be ensured and, more generally, to use and operate it in the same conditions of security. This Agreement may be freely reproduced and published, provided it is not altered, and that no provisions are either added or removed herefrom.

Copyright

• Copyright Daniel Berthereau, 2018-2026 (see Daniel-KM on GitLab)