About

RDFaCE is an online RDFa content editor based on TinyMCE. It supports different views for semantic content authoring and uses existing semantic Web APIs to facilitate annotating and editing of RDFa contents. As depicted in the following picture, the RDFaCE system architecture consists of three layers: Rich Text Editor, RDFaCE plugin and External Services layer.

RDFaCE supports four different views for semantic text authoring:

• WYSIWYG View. What-You-See-Is-What-You-Get
• WYSIWYM View. What-You-See-Is-What-You-Mean
• RDF Triple View.
• Source Code View.

The views are synchronized such that changes made in one of the views automatically update the others.

Furthermore, RDFaCE employs Sindice, Swoogle and Prefix.cc APIs for resource suggestion (providing appropriate URIs for subjects, properties and namespaces). Another feature supported by RDFaCE is combining the results of multiple NLP APIs. Using this approach, we can harness synergies arising from the combination of different approaches for automatic text annotation. Currently, RDFaCE supports 7 NLP APIs namely Alchemy,Extractiv, Open Calais, Ontos,Evri, Saplo,Lupedia and DBpedia spotlight.

The RDFaCE approach is very versatile and can be applied in a vast number of use cases. rNews, Ontowiki and Wordpress are three use cases of RDFaCE.

RDFaCE-Lite

RDFaCE-Lite is a lite version of RDFaCE which is specifically developed to support the rNews standard for annotating news and blog posts. It supports user-friendly editing of entities by only one click. It also provides support for Microdata (according to Schema.org) as an alternative annotation format. The demo is available at http://rdface.aksw.org/lite/.

How to Use

The normal annotation process in RDFaCE consists of four steps:

1. Defining appropriate namespaces by clicking button.
2. Selecting a fragment of the text.
3. Assigning the subject (and type) to be used for the selected fragment by clicking button.
4. Inserting triples by assigning properties using button.

Triples can be seen by launching the triple browser ( button). You can go to setting and select one or multiple NLP APIs plus your combination strategy to automatically annotate your content by clicking . To see a report on the entities found by each API, you can press after determining your desired combination. To instantly add a triple using rNews vocabulary, just select a part of the text and then on the context menu (which appears on mouse right click) select your desired type or property.

Download

You can download the beta version of RDFaCE from here. RDFaCE is also available as a Wordpress Plugin.

Configuration

To configure RDFaCE plugin you need to follow the normal procedure of adding a plugin in Tiny MCE (More info...). To enable automatic annotation, you need to register for each API and get an API key for it. Then go to RDFaCE\php folder and open proxy.php file. In this file you can set API keys for your desirable enrichment APIs. You can register for current five available APIs at:

• Alchemy
• Extractiv
• Open Calais
• Ontos
• Evri
• Saplo
• Lupedia
• DBpedia spotlight

Then you need to go to rdface/js/util/config.php and set the path of your proxy file.

Related Projects

• NIF (http://aksw.org/Projects/NIF)
• FOX (http://aksw.org/Projects/FOX)