rdf-viz

A tool for visualizing RDF files in graph form.

Usage

RDF source files and other options are provided via configuration file input. If using the packaged version: rdf-viz <config> (note that due to the packaging mechanism, config paths must be relative to the executable, not the CWD). If running from the repository: npm i at least once, followed by npm start -- <config>.

RDF display

Particular well-known RDF relationships are displayed in a special manner to improve visualization:

• rdf:type: Types are displayed in the upper tooltip on node mouseover.
• rdf:value: Literal value relationships are displayed in the lower tooltip on node mouseover. The datatype or language for any given value will be displayed in a further tooltip upon mousing over that value.
• rdf:List: List relationships are grouped together and treated similar to a single node.

Configuration

Configuration files are JSON files which can include the following fields:

• @include: Configuration file(s) to inherit from. Can be a path pointing to another configuration JSON relative to the current configuration file or a string referencing one of the built-in configurations.
• source: A map of source files (either URLs or glob-style paths) to their media types (e.g. "application/ld+json" or "text/turtle").
• proxy: A map of URL paths to local directories. The visualizer will redirect any references under a given path to the corresponding directory; this is useful when, for example, JSON-LD files reference contexts by URL that need to be retrieved from disk.
• namespace: A map of namespace abbreviations to their full URL, providing compacted URLs for visualization.
• style: Replacements for the default styles for ease of visualization. Each group is a map of URL globs (full or compacted using the configured namespaces) to Cytoscape.js style objects.
  • type: Node styles for rdf:type relations.
  • node: Node styles by term URL. Includes the following special styles:
    • node-presentation: Determines how RDF terms are included in the graph. Can be one of single (each unique term is displayed once; default), multiple (each reference to a term is displayed as a unique node), or none (the term is not displayed).
  • edge: Edge styles by predicate URL. Includes the following special styles:
    • node-presentation: As per node (above), but acting on the edge and/or its target.
    • layout-direction: Determines how the layout algorithm treats these edges. Can be one of forward (default) or reverse.
• option: Miscellaneous display options:
  • showTypeEdge: One of never (types are only displayed in the tooltips; default), unstyled (type edges are displayed for types which don't have an applied style), or always (type edges are always displayed).

Built-in configurations

The following are the available built-in configuration files that can be imported. They provide no sources, but include namespaces and styles useful for viewing various RDF standards.

• rdfs: Useful for viewing RDF Schema class diagrams.
• sh: Useful for viewing SHACL constraints.