Node and Edge Types

In a term representation, all nodes and edges have a type which is an arbitrary string, see diagram in previous section. All nodes or edges of the same class share a common type (the notion of a class depends on the concrete application). It is possible to define the visualization of a class of node or edges in a central file called visualization definition. This is much more comfortable than to deal with individual attributes (see next section) for a lot of nodes and edges. A visualization definition has to be sent to the API with the commands of category visual. For example, it is possible to specify a rule to draw all nodes that belong to class "X" with a red circle, instead of using attributes for each individual node. When a rule of the visualization definition is changed, all nodes or edges of that particular class are automatically modified. So, the central visualization definition is a comfortable method to define a universal visualization for a family of graphs. More information about visualization definitions is available in the concept chapter.

Note: with the command-line option -init you can supply a file with API commands that are executed at the start of uDraw(Graph). When you put your definitions into such an initialization file, you will be able to use visualization definitions without the API. Unfortunately, you will not be able to change the definitions at run-time in this case.