This page has a table of the different nodes types in the XDI graph model and the syntax for each.
- 2015-05-17 - Drummond Reed: changed to reference a public spreadsheet (since trying to maintain the syntax reference table in a wiki table format was too laborious).
- 2015-01-19 - Drummond Reed: added syntax for variable root nodes
- 2014-12-18 - Drummond Reed: no substantive changes -- added written descriptions of all entity node types
- 2014-11-11 - Drummond Reed: updated entire table to include all forms of syntax, i.e., instances, variables, and definitions.
See the history of this page for earlier versions.
The XDI graph model is the foundation of XDI as a semantic data interchange format and protocol. It defines how data expressed in XDI can be addressed and described. The underlying requirements for this model have been developed by the XDI TC since its inception in 2004. Just as JSON reflect the set of universal data structures needed by almost all programming languages, the XDI graph model reflects the set of universal data modeling constructs needed by almost all data modeling and schema languages.
Context Nodes and Literal Nodes
The XDI graph model has two fundamental node types:
Literal nodes contain the raw data described by an XDI graph. XDI literal nodes are essentially identical to RDF literal nodes (except they are all uniquely addressable, and typing is handled differently).
Context nodes are all the other node types in the XDI graph model (root nodes, entity nodes, attribute nodes) that provide context for the literal nodes.
Context Node Types
See this spreadsheet for a summary of XDI syntax by context node type.