Modeling Canvas
The Modeling Canvas is placed at the center of the interface, and manages the ontology diagrams through tabs. By clicking on one of the tabs you open the respective diagram. Once you have opened the diagram, you can start editing it.
If you wish to add a new resource to the ontology, you can select a Class, Object Property, Data Property, Datatype, Individual or Literal node from the Palette, and drag it into the currently selected diagram.
This operation will trigger the opening of the IRI Builder, through which you can define the new IRI, and add it to the ontology. Like any resource, the IRI of the element is defined by a combination of the prefix (which is assigned to a namespace) you choose and the input you provide. The former is chosen from a drop-down Prefix list, the latter is written into the Input text area.
Eddy offers a wide variety of drawing functionalities, from standard basic diagram editing features to more advanced features that are specifically tailored for Graphol.
Some of the more commonly-used diagram editing features are:
- bending edges or moving edge anchor points
- resizing nodes
- moving or editing labels (by holding down the
Shiftbutton and dragging the label to the desired position) - cutting/copying, pasting or dragging portions of diagrams
Each node in the diagram has a contextual menu which you can access by right-clicking on the node.
Selecting the Annotations option open up the Annotations Tab in the IRI Builder. You can add one or more annotations to any IRI in the ontology, by selecting the annotation property, which specifies what kind of annotation you are building, typing in the content, and defining the content type. In case of PlainLiterals, you can also choose the language.
By default, the rdfs:label annotation type must be used to define the label (or labels, if you wish to add more than one) of an IRI.
Eddy allows to repeat the same entity in the ontology through multiple nodes. This is necessary because entities that occur in numerous axioms in the ontology would otherwise be represented by a single node with numerous outgoing or incoming edges, which could create layout and comprehension issues. Additionally, in Eddy an ontology can be composed by several diagrams, so this representation through multiple nodes can occur even across different diagrams.
The Occurrences option lets you quickly move from one occurrence to the other of a given entity in the ontology.
If you choose the Compose option, you can select some Graphol-specific drawing features to help you to rapidly perform commonly recurring tasks.
Here are some examples of the Graphol drawing features which you can use through the contextual menus:
- you can choose to automatically add the domain or range role on an object property node, which results in a new white or black node labeled ‘exists’ to be added to the diagram, linked to the selected node through an input edge
- you can switch the direction of the role, which inverts the domain and range restriction nodes
- you can switch the label of a hexagon or a box, which instantly changes the kind of operator represented by that node. This operation is syntactically controlled in real-time by the system: Eddy is provided with a context-aware mechanism that prevents the user from selecting an operator node type that would result in the composition of an invalid Graphol expression
Assume you want to change the IRI of an entity in the ontology. This change obviously needs to be repeated for every occurrence of a node representing the IRI that is being updated. The Refactor option allows you to perform the change only once, since it automatically propagates them throughout the ontology.