Drawing Basics#

The CEMENTO package can take any single or multi-page draw.io file and process it. However, parsing it properly to get the right RDF triples is a different matter. This guide goes through some things for you to keep in mind so your diagrams actually correspond with your .ttl outputs.

Drawing with draw.io#

If you have not used draw.io before, please refer to their comprehensive tutorials here. Where you draw your draw.io doesn’t really affect the package performance as long as CEMENTO has access to the output .drawio file. Once you are familiar with the basics of .drawio, there are a few additional things to note:

  • Use the .drawio file extension for your diagram! This is to avoid ambiguity between RDF/XML files and your diagrams.

  • You can use any simple shape for your classes, literals and instances. HOWEVER, any shape you put (including textboxes) will be considered a class, literal or instance.

  • You draw predicates with arrows. Please make sure that your arrows actually connect to the shape and not just look as if it does.

  • Your arrows must be drawn from source to target. Your arrows must be end-arrow only.

  • Predicate labels must be done on the arrow itself. Putting a box on top of an arrow will not work. Only one label per arrow.

  • Literals must come with double-quotes regardless of data type. Avoid using nested double-quotes.

  • You can draw a shape with the text ‘A-Box’ or ‘T-Box’ and a line without a label for annotations. Everything else is treated as part of the ontology.

A Walkthrough#

The following diagram goes through an example supplied with the repository called happy-example.drawio with its corresponding .ttl file called happy-example.ttl. We used CCO terms to model the ontology, so please download that file and place it into your ontology reference folder so you can follow along.

Having trouble? Download the figure above as an svg image or draw.io diagram.

In Case You Missed It#

The diagram above goes through all that you need to know to start making diagrams you can convert to RDF files (Isn’t that cool?); but in case it wasn’t obvious, here is a summary of features you can leverage that CEMENTO will understand:

  • Term matching.

    Any term and predicate you create will be matched with a term. Just make sure to use the right prefix. More details here.

  • Shorthand aliasing.

    You can add labels and alt-labels to your term by simply adding them parenthetically. For example: mds:MyCustomTerm (my label, my alt label). The first term in the comma-separated series is always the label. Any subsequent terms are alt-labels (No language support yet).

  • Match suppression.

    If you don’t want a term substituted or matched, just add an asterisk to the name (*).

  • Custom terms and prefixes.

    New terms without prefixes will be matched with our default namespace, mds. To add a custom prefix, just use the prefix, but add it to a prefixes.json file (how to do that here).

  • Literal languages and data types.

    Just write your value the way you would write it in turtle, i.e. "Happy Gilmore"^^xsd:string or "Happy Gilmore"@en to define datatypes and set a language respectively.

    NOTE: The package now supports imported datatypes! Locally defined (same-file) datatype definitions are not supported yet.