Validation, traversal and transformation of RDF graphs.

Shape Expressions is a structural schema language for RDF graphs. It allows one to describe profiles of data like this:

# our EmployeeShape reuses the FOAF ontology
<EmployeeShape> {                # An <EmployeeShape> has:
    foaf:givenName  xsd:string+,   # at least one givenName.
    foaf:familyName xsd:string,    # one familyName.
    foaf:phone      IRI*,          # any number of phone numbers.
    foaf:mbox       IRI            # one FOAF mbox.
}

# Employee7 matches EmployeeShape
<http://a.example/Employee7>
    foaf:givenName  "Robert", "Taylor" ;
    foaf:familyName "Johnson" ;
    # no phone number needed
    foaf:mbox       <mailto:rtj@example.com>
    .

Features

• datatype constraints
• value sets
• XML Schema facets
• nested shapes
• additive property constraints
• algabraics (or, and)
• negated properties
• incoming arcs
• node kind (IRI, BNode or literal)
• open/closed shapes and properties
• JSON schema format
• JSON validation results

• Validators

  Implementation	Platform/Language
  shex.js	(wiki,repo), runs on n3.js
  ShExJava	Java
  ShEx-s	Scala (Jena or RDF4J)
  Ruby ShEx	Ruby
  PyShEx	Python
  Apache Jena ShEx	Java (repo)

• WebApps

  try it!	repo	Environment
  rdfshape	github public	React
  shex-simple	github public	custom js
  shexmap-simple	github public	custom js
  shex-author	github public	React
  ace-shexc	github public	Ace Editor
  YaShE	github public	Javascript

• Tools

  Tool	Description
  sheXer	automatic extraction of ShEx schemata in RDF graphs
  shex-form	use ShEx to create and populate HTML forms
  ST3 shexc.syntax	Syntax highlighting for ShExC in Sublime Text 3
  VSCode ShEx Extensions	Syntax highlighting for ShExC in VSCode
  ShExML	map and merge heterogeneous data sources
  shexc-mode	An Emacs mode for editing ShEx (good for Turtle too).

• Tutorials

  • Tutorial "Shapes Applications and tools" at ISWC'20 (contains slides and videos)
  • Validating RDF (book)