# SHACL: Shapes Constraint Language (SHACL) for Ruby This is a pure-Ruby library for working with the [Shape Constraint Language][SHACL Spec] to validate the shape of [RDF][] graphs. [![Gem Version](https://badge.fury.io/rb/shacl.png)](https://badge.fury.io/rb/shacl) [![Build Status](https://github.com/ruby-rdf/shacl/workflows/CI/badge.svg?branch=develop)](https://github.com/ruby-rdf/shacl/actions?query=workflow%3ACI) [![Coverage Status](https://coveralls.io/repos/github/ruby-rdf/shacl/badge.svg?branch=develop)](https://coveralls.io/github/ruby-rdf/shacl?branch=develop) [![Gitter chat](https://badges.gitter.im/ruby-rdf/rdf.png)](https://gitter.im/ruby-rdf/rdf) ## Features * 100% pure Ruby with minimal dependencies and no bloat. * Fully compatible with [SHACL][SHACL Spec] specifications. * 100% free and unencumbered [public domain](https://unlicense.org/) software. [Implementation Report](https://ruby-rdf.github.io/shacl/etc/earl.html) Install with `gem install shacl` ## Description The SHACL gem implements a [SHACL][SHACL Spec] Shape Expression engine. ## Examples require 'linkeddata' require 'shacl' graph = RDF::Graph.load("etc/doap.ttl") shacl = SHACL.open("etc/doap.shacl") report = shacl.execute(graph) #=> ValidationReport(conform?, results*) ## Command Line TODO: When the `linkeddata` gem is installed, RDF.rb includes a `rdf` executable which acts as a wrapper to perform a number of different operations on RDF files, including SHACL. The commands specific to SHACL is *`shacl`: Validate repository given shape Using this command requires `shacl`, which references a URI or file path to the SHACL shapes graph. Other options are `shape` and `focus`. Example usage: rdf shacl https://ruby-rdf.github.io/shacl/etc/doap.ttl \ --shape https://ruby-rdf.github.io/shacl/etc/doap-shape.ttl The result will add the SHACL validation report to the output graph, optionally replacing the graph with the results, expressing the results as an s-expression, or adding the results as output messages. ## Documentation ## Implementation Notes Similar to the [ShEx gem][] and to the general strategy for querying graphs in the [SPARQL gem][], the strategy is to parse SHACL shapes into executable operators, which are called recursively to create result sets corresponding to matched nodes and properties. The shape graph is parsed into JSON-LD, and then converted into [S-Expressions][], which match the execution path. These [S-Expressions][] can be parsed to recreate the executable shape constraints. Evaluating the shapes against a graph results in a {SHACL::ValidationReport} indicating conformance, along with a set of individual {SHACL::ValidationResult} instances. The resulting validation report can be compared with other validation reports, used as native Ruby objects, serialized to s-expressions, or used as an RDF::Enumerable to retrieve the RDF representation of the report, as defined in [SHACL Spec][]. ### Matching Entailed Triples Many tests check for entailed triples, such as entailed super-classes of explicit `rdf:type` values. If this is required for a given application, the [RDF::Reasoner][] gem can be used to create such entailed triples. require 'shacl' require 'rdf/reasoner' RDF::Reasoner.apply(:rdfs) graph = RDF::Graph.load("etc/doap.ttl") graph.entail! shacl = SHACL.open("etc/doap.shacl") results = shacl.execute(graph) #=> [ValidationResult, ...] ### Future work This implementation is certainly not performant. Some things that can be be considered in future versions: * Support for SHACL-SPARQL * Index shapes on `targetNode` and `targetClass` and other targets to allow a more efficient query to find relevant resources in the data graph and not simply iterrate through each top-level shape. * Cache target nodes as JSON-LD to reduce the need to separately query for each constraint. * Reasoner should support limited RDFS/OWL entailment from the data graph, not just pre-defined vocabularies. ## Dependencies * [Ruby](https://ruby-lang.org/) (>= 2.6) * [RDF.rb](https://rubygems.org/gems/rdf) (~> 3.2) * [SPARQL](https://rubygems.org/gems/sparql) (~> 3.2) * [json-ld](https://rubygems.org/gems/json-ld) (~> 3.2) * [sxp](https://rubygems.org/gems/sxp) (~> 1.2) ## Installation The recommended installation method is via [RubyGems](https://rubygems.org/). To install the latest official release of RDF.rb, do: % [sudo] gem install shacl ## Download To get a local working copy of the development repository, do: % git clone git://github.com/ruby-rdf/shacl.git Alternatively, download the latest development version as a tarball as follows: % wget https://github.com/ruby-rdf/shacl/tarball/master ## Resources * * * ## Mailing List * ## Author * [Gregg Kellogg](https://github.com/gkellogg) - ## Contributing This repository uses [Git Flow](https://github.com/nvie/gitflow) to mange development and release activity. All submissions _must_ be on a feature branch based on the _develop_ branch to ease staging and integration. * Do your best to adhere to the existing coding conventions and idioms. * Don't use hard tabs, and don't leave trailing whitespace on any line. Before committing, run `git diff --check` to make sure of this. * Do document every method you add using [YARD][] annotations. Read the [tutorial][YARD-GS] or just look at the existing code for examples. * Don't touch the `.gemspec` or `VERSION` files. If you need to change them, do so on your private branch only. * Do feel free to add yourself to the `CREDITS` file and the corresponding list in the the `README`. Alphabetical order applies. * Don't touch the `AUTHORS` file. If your contributions are significant enough, be assured we will eventually add you in there. * Do note that in order for us to merge any non-trivial changes (as a rule of thumb, additions larger than about 15 lines of code), we need an explicit [public domain dedication][PDD] on record from you, which you will be asked to agree to on the first commit to a repo within the organization. Note that the agreement applies to all repos in the [Ruby RDF](https://github.com/ruby-rdf/) organization. ## License This is free and unencumbered public domain software. For more information, see or the accompanying {file:LICENSE} file. [RDF]: https://www.w3.org/RDF/ [YARD]: https://yardoc.org/ [YARD-GS]: https://rubydoc.info/docs/yard/file/docs/GettingStarted.md [PDD]: https://unlicense.org/#unlicensing-contributions [S-Expressions]: https://en.wikipedia.org/wiki/S-expression [RDF.rb]: https://ruby-rdf.github.io/rdf [RDF::Reasoner]: https://ruby-rdf.github.io/rdf-reasoner [SPARQL gem]: https://ruby-rdf.github.io/sparql [SXP gem]: https://ruby-rdf.github.io/sxp [SHACL Spec]: https://www.w3.org/TR/shacl/ [ShEx gem]: https://ruby-rdf.github.io/shex