The Graph Babel project emanated from the need to simplify the collaborative authoring of graphs, and to generate different graph formats from the same input.
Although several graph languages exist, they suffer from the tight bonds with the renderer and/or the GUI-based product that uses them. As a result, it is hard to move from one graph technology to another.
The base Elements that shape any Graph are Nodes and Links between
Nodes (edges). A collection of Nodes and Links are a Graph.
In addition, Nodes can be containers for Elements (Graphs, Nodes and
Links).
A Style can be defined for assigning rendering properties to an Element.
Any Element can refer to a Style definition.
All Elements are visible in the global document scope.
Style definitions can occur at the level of a Graph or at any level up.
Scoping requires Style definitions to appear before Element definitions, at any level.
Style definitions can extend, overwrite portions (or all) previous Style definitions with the same name.
The need for defining a simple text-based graph modelling language, and to generate graphs in different formats, emanated from the European ITEA4 FireBIM project. During a workshop, a set of sticky notes of different colors have been used to represent different concepts in a work flow describing the current and future user journey. These paper flows were transformed into a digital format and the participants were invited to collaboratively enhance and refine these flows by using online tools.
One problem we faced, was the unwanted clean-up of the source file while editing, and the need to manually assign colors and shapes to nodes. Another was the difficulty in identifying the nodes (and edges) in the graph while commenting, reviewing and editing.
An initial attempt to generate 'canonical' graph source files from our side made us realize that we were trying to (ab)use a graph format for purposes not intended by that format/technology. In reality we needed something different, allowing us to be in control of the graph definition itself, and to use generators for generating graph representations that could be fed to other graph technologies (such as Mermaid graphs).
In principle custom generators for any graph format could be generated, e.g. for generating SHACL shapes from graphs adhering to a specific syntax.