SlideShare a Scribd company logo
1 of 44
SHACL by example
RDF Validation tutorial
Eric Prud'hommeaux
World Wide Web Consortium
MIT, Cambridge, MA, USA
Harold Solbrig
Mayo Clinic, USA
Jose Emilio Labra Gayo
WESO Research group
University of Oviedo, Spain
Iovka Boneva
LINKS, INRIA & CNRS
University of Lille, France
SHACL
W3c Data Shapes WG deliverable
https://www.w3.org/TR/shacl/
Inspired by SPIN, OSLC & bits of ShEx
SPARQL based extension mechanism
RDF vocabulary
Human friendly syntax inspired by ShEx proposed as a WG Note *
* https://w3c.github.io/data-shapes/shacl-compact-syntax/
Some definitions about SHACL
Shape: collection of targets and constraints components
Targets: specify which nodes in the data graph must conform to a shape
Constraint components: Determine how to validate a node
Shapes graph: an RDF graph that contains shapes
Data graph: an RDF graph that contains data to be validated
Example
Try it. RDFShape http://goo.gl/FqXQpD
prefix : <http://example.org/>
prefix sh: <http://www.w3.org/ns/shacl#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
prefix schema: <http://schema.org/>
:UserShape a sh:NodeShape ;
sh:targetNode :alice, :bob, :carol ;
sh:property [
sh:path schema:name ;
sh:minCount 1;
sh:maxCount 1;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:email ;
sh:minCount 1;
sh:maxCount 1;
sh:nodeKind sh:IRI ;
] .
:alice schema:name "Alice Cooper" ;
schema:email <mailto:alice@mail.org> .
:bob schema:firstName "Bob" ;
schema:email <mailto:bob@mail.org> .
:carol schema:name "Carol" ;
schema:email "carol@mail.org" .
Shapes graph
Data graph


Target declarations
Targets specify nodes that must be validated against the shape
Several types
Value Description
targetNode Directly point to a node
targetClass All nodes that have a given type
targetProperty All nodes that have a given property
target General mechanism based on SPARQL
Target node
Directly declare which nodes must validate the against the shape
:UserShape a sh:NodeShape ;
sh:targetNode :alice, :bob, :carol ;
sh:property [
sh:path schema:name ;
sh:minCount 1;
sh:maxCount 1;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:email ;
sh:minCount 1;
sh:maxCount 1;
sh:nodeKind sh:IRI ;
] .
:alice schema:name "Alice Cooper" ;
schema:email <mailto:alice@mail.org> .
:bob schema:givenName "Bob" ;
schema:email <mailto:bob@mail.org> .
:carol schema:name "Carol" ;
schema:email "carol@mail.org" .
Target class
Selects all nodes that have a given type
Looks for rdf:type declarations*
* Also looks for rdfs:subClassOf*/rdf:type declarations
:UserShape a sh:NodeShape ;
sh:targetClass :User ;
sh:property [
sh:path schema:name ;
sh:minCount 1;
sh:maxCount 1;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:email ;
sh:minCount 1;
sh:maxCount 1;
sh:nodeKind sh:IRI ;
] .
:alice a :User;
schema:name "Alice Cooper" ;
schema:email <mailto:alice@mail.org> .
:bob a :User;
schema:givenName "Bob" ;
schema:email <mailto:bob@mail.org> .
:carol a :User;
schema:name "Carol" ;
schema:email "carol@mail.org" .
Implicit target class
A shape with type sh:Shape and rdfs:Class is a scope class of itself
The targetClass declaration is implicit
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path schema:name ;
sh:minCount 1;
sh:maxCount 1;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:email ;
sh:minCount 1;
sh:maxCount 1;
sh:nodeKind sh:IRI ;
] .
:alice a :User;
schema:name "Alice Cooper" ;
schema:email <mailto:alice@mail.org> .
:bob a :User;
schema:givenName "Bob" ;
schema:email <mailto:bob@mail.org> .
:carol a :User;
schema:name "Carol" ;
schema:email "carol@mail.org" .
Types of shapes
Type Description
Node shapes Constraints about a given focus node
Property shapes Constraints about a property and the values of a path
for a node
Shape
target declarations
NodeShape PropertyShape
constraint components
constraint components
sh:path: rdfs:Resource
:alice a :User .
<http://example.org/bob> a :User .
_:1 a :User .
Node Shapes
Constraints about a focus node

:User a sh:NodeShape ;
sh:nodeKind sh:IRI .
Property shapes
Constraints about a given property and its values for the focus node
sh:property associates a shape with a property constraint
sh:path identifies the path
:User a sh:NodeShape ;
sh:property [
sh:path schema:email ;
sh:nodeKind sh:IRI
] .
:alice a :User ;
schema:email <mailto:alice@mail.org> .
:bob a :User;
schema:email <mailto:bob@mail.org> .
:carol a :User;
schema:email "carol@mail.org" .


Paths in property shapes
Example with inverse path
inversePath, zeroOrMorePath, alternativePath,
oneOrMorePath, ...
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path [sh:inversePath schema:follows ];
sh:nodeKind sh:IRI ;
] .
:alice a :User;
schema:follows :bob .
:bob a :User .
:carol a :User;
schema:follows :alice .
_:1 schema:follows :bob .

Core constraint components
Type Constraints
Cardinality minCount, maxCount
Types of values class, datatype, nodeKind
Values node, in, hasValue
Range of values minInclusive, maxInclusive
minExclusive, maxExclusive
String based minLength, maxLength, pattern, stem, uniqueLang
Logical constraints not, and, or, xone
Closed shapes closed, ignoredProperties
Property pair constraints equals, disjoint, lessThan, lessThanOrEquals
Non-validating constraints name, value, defaultValue
Qualified shapes qualifiedValueShape, qualifiedMinCount, qualifiedMaxCount
Cardinality constraints
Constraint Description
minCount Restricts minimum number of triples involving the focus
node and a given predicate.
Default value: 0
maxCount Restricts maximum number of triples involving the focus
node and a given predicate.
If not defined = unbounded
Try it. http://goo.gl/9AwtFK
:User a sh:NodeShape ;
sh:property [
sh:path schema:follows ;
sh:minCount 2 ;
sh:maxCount 3 ;
] .
:alice schema:follows :bob,
:carol .
:bob schema:follows :alice .
:carol schema:follows :alice,
:bob,
:carol,
:dave .


Datatypes of values
Constraint Description
datatype Restrict the datatype of all value nodes to a given value
:User a sh:NodeShape ;
sh:property [
sh:path schema:birthDate ;
sh:datatype xsd:date ;
] .
Try it: http://goo.gl/eDwxsU
:alice schema:birthDate "1985-08-20"^^xsd:date .
:bob schema:birthDate "Unknown"^^xsd:date .
:carol schema:birthDate 1990 .


Class of values
Constraint Description
class Verify that each node in an instance of some class
It also allows instances of subclasses*
(*) The notion of SHACL instance is different from RDFS
It is defined as rdfs:subClassOf*/rdf:type
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path schema:follows ;
sh:class :User
] .
:Manager rdfs:subClassOf :User .
:alice a :User;
schema:follows :bob .
:bob a :Manager ;
schema:follows :alice .
:carol a :User;
schema:follows :alice, :dave .
:dave a :Employee .

Kind of values
Constraint Description
nodeKind Possible values:
BlankNode, IRI, Literal,
BlankNodeOrIRI, BlankNodeOrLiteral, IRIOrLiteral
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path schema:name ;
sh:nodeKind sh:Literal ;
];
sh:property [
sh:path schema:follows ;
sh:nodeKind sh:BlankNodeOrIRI
];
sh:nodeKind sh:IRI .
:alice a :User;
schema:name _:1 ;
schema:follows :bob .
:bob a :User;
schema:name "Robert";
schema:follows [ schema:name "Dave" ] .
:carol a :User;
schema:name "Carol" ;
schema:follows "Dave" .
_:1 a :User . 


Constraints on values
Constraint Description
hasValue Verifies that the focus node has a given value
in Enumerates the value nodes that a property may have
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path schema:affiliation ;
sh:hasValue :OurCompany ;
];
sh:property [
sh:path schema:gender ;
sh:in (schema:Male schema:Female)
] .
:alice a :User;
schema:affiliation :OurCompany ;
schema:gender schema:Female .
:bob a :User;
schema:affiliation :AnotherCompany ;
schema:gender schema:Male .
:carol a :User;
schema:affiliation :OurCompany ;
schema:gender schema:Unknown . 

Constraints on values with another shape
Constraint Description
node* All values of a given property must have a given shape
Recursion is not allowed in current SHACL
:User a sh:NodeShape, rdfs:Class ;
sh:property [
sh:path schema:worksFor ;
sh:node :Company ;
] .
:Company a sh:Shape ;
sh:property [
sh:path schema:name ;
sh:datatype xsd:string ;
] .
:alice a :User;
schema:worksFor :OurCompany .
:bob a :User;
schema:worksFor :Another .
:OurCompany
schema:name "OurCompany" .
:Another
schema:name 23 .

*recently renamed as sh:shape
Value shapes and recursion
Could we define cyclic data models as the following?
:User a sh:NodeShape ;
sh:property [
sh:path schema:worksFor ;
sh:node :Company ;
] .
:Company a sh:Shape ;
sh:property [
sh:path schema:name ;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:employee ;
sh:node :User ;
] .
:User :Company
schema:name xsd:string
schema:worksFor
schema:employee
No, current SHACL specification doesn't allow this
:alice schema:worksFor :OneCompany .
:bob schema:worksFor :OneCompany .
:carol schema:worksFor :OneCompany .
:OneCompany schema:name "One" ;
schema:employee :alice, :bob, :carol .
Don't try it 
SHACL approach to avoid recursion
Add rdf:type arcs for every resource and use sh:class
:User a sh:NodeShape ;
sh:property [
sh:path schema:worksFor ;
sh:class :Company ;
] .
:Company a sh:Shape ;
sh:property [
sh:path schema:name ;
sh:datatype xsd:string ;
] ;
sh:property [
sh:path schema:employee ;
sh:class :User ;
] .
:User :Company
schema:name xsd:string
schema:worksFor
schema:employee
Try it: http://goo.gl/wlVZJR
:alice a :User ;
schema:worksFor :OneCompany .
:bob a :User ;
schema:worksFor :OneCompany .
:carol a :User ;
schema:worksFor :Something .
:OneCompany a :Company ;
schema:name "One" ;
schema:employee :alice, :bob, :carol .

Logical Operators
Constraint Description
and Conjunction of a list of shapes
or Disjunction of a list of shapes
not Negation of a shape
xone Exactly one (similar XOR for 2 arguments)
and
Default behavior
:User a sh:NodeShape ;
sh:and (
[ sh:property [
sh:path schema:name;
sh:minCount 1;
]
]
[ sh:property [
sh:path schema:affiliation;
sh:minCount 1;
]
]
) .
:User a sh:Shape ;
[ sh:property [
sh:path schema:name;
sh:minCount 1;
]
]
[ sh:property [
sh:path schema:affiliation;
sh:minCount 1;
]
]
.
≡
or
:User a sh:NodeShape ;
sh:or (
[ sh:property [
sh:predicate foaf:name;
sh:minCount 1;
]
]
[ sh:property [
sh:predicate schema:name;
sh:minCount 1;
]
]
) .
:alice schema:name "Alice" .
:bob foaf:name "Robert" .
:carol rdfs:label "Carol" . 
not
:NotFoaf a sh:NodeShape ;
sh:not [ a sh:Shape ;
sh:property [
sh:predicate foaf:name ;
sh:minCount 1 ;
] ;
] .
:alice schema:name "Alice" .
:bob foaf:name "Robert" .
:carol rdfs:label "Carol" .

Exactly one
Pending example...
Value ranges
Constraint Description
minInclusive
maxInclusive
minExclusive
maxExclusive
Try it: http://goo.gl/qnd66j
:Rating a sh:NodeShape ;
sh:property [
sh:path schema:ratingValue ;
sh:minInclusive 1 ;
sh:maxInclusive 5 ;
sh:datatype xsd:integer
] .
:bad schema:ratingValue 1 .
:average schema:ratingValue 3 .
:veryGood schema:ratingValue 5 .
:zero schema:ratingValue 0 .
String based constraints
Constraint Description
minLength Restricts the minimum string length on value nodes
maxLength Restricts the maximum string length on value nodes
pattern Checks if the string value matches a regular expression
stem Checks if all value nodes are IRIs and the IRI starts with a given string value
uniqueLang Checks that no pair of nodes use the same language tag
minLength/maxLength
Try it: http://goo.gl/NrJl83
:User a sh:NodeShape ;
sh:property [
sh:path schema:name ;
sh:minLength 4 ;
sh:maxLength 10 ;
] .
:alice schema:name "Alice" .
:bob schema:name "Bob" .
:carol schema:name :Carol .
:strange schema:name _:strange .

Checks the string representation of the value
This cannot be applied to blank nodes
If minLength = 0, no restriction on string length

pattern
Checks if the values matches a regular expression
It can be combined with sh:flags
:Product a sh:NodeShape ;
sh:property [
sh:path schema:productID ;
sh:pattern "^Pd{3,4}" ;
sh:flags "i" ;
] .
:car schema:productID "P2345" .
:bus schema:productID "p567" .
:truck schema:productID "P12" .
:bike schema:productID "B123" . 

Try it: http://goo.gl/BsHpqu
uniqueLang
Checks that no pair of nodes use the same language tag
Try it: http://goo.gl/B1PNcO
:Country a sh:NodeShape ;
sh:property [
sh:path schema:name ;
sh:uniqueLang true
] .
:spain schema:name "Spain"@en,
"España"@es .
:france schema:name "France"@en,
"Francia"@es .
:usa schema:name "USA"@en,
"United States"@en. 
Property pair constraints
Constraint Description
equals The sets of values of both properties at a given focus node must be equal
disjoint The sets of values of both properties at a given focus node must be different
lessThan The values must be smaller than the values of another property
lessThanOrEquals The values must be smaller or equal than the values of another property
Try it: http://goo.gl/BFzMoz
:User a sh:NodeShape ;
sh:property [
sh:path schema:givenName ;
sh:equals foaf:firstName
];
sh:property [
sh:path schema:givenName ;
sh:disjoint schema:lastName
] .
:alice schema:givenName "Alice";
schema:lastName "Cooper";
foaf:firstName "Alice" .
:bob schema:givenName "Bob";
schema:lastName "Smith" ;
foaf:firstName "Robert" .
:carol schema:givenName "Carol";
schema:lastName "Carol" ;
foaf:firstName "Carol" .


Closed shapes
Constraint Description
closed Valid resources must only have values for properties that appear in sh:property
ignoredProperties Optional list of properties that are also permitted
:User a sh:NodeShape ;
sh:closed true ;
sh:ignoredProperties ( rdf:type ) ;
sh:property [
sh:path schema:givenName ;
];
sh:property [
sh:path schema:lastName ;
] .
:alice schema:givenName "Alice";
schema:lastName "Cooper" .
:bob a :Employee ;
schema:givenName "Bob";
schema:lastName "Smith" .
:carol schema:givenName "Carol";
schema:lastName "King" ;
rdfs:label "Carol" .

Try it: http://goo.gl/wcW16o
Non-validating constraints
Can be useful to annotate shapes or design UI forms
Constraint Description
name Provide human-readable labels for a property
description Provide a description of a property
order Relative order of the property
group Group several constraints together
:User a sh:NodeShape ;
sh:property [
sh:path schema:url ;
sh:name "URL";
sh:description "User URL";
sh:order 1
];
sh:property [
sh:path schema:name ;
sh:name "Name";
sh:description "User name";
sh:order 2
] .
Non-validating constraints
:User a sh:NodeShape ;
sh:property [ sh:path schema:url ;
sh:name "URL";
sh:group :userDetails
];
sh:property [ sh:path schema:name ;
sh:name "Name"; sh:group :userDetails
];
sh:property [ sh:path schema:address ;
sh:name "Address"; sh:group :location
];
sh:property [ sh:path schema:country ;
sh:name "Country"; sh:group :location
] .
:userDetails a sh:PropertyGroup ;
sh:order 0 ;
rdfs:label "User details" .
:location a sh:PropertyGroup ;
sh:order 1 ;
rdfs:label "Location" .
User details
URL: _____________________
Name: ___________________
Location
Address: __________________
Country: __________________
An agent could generate a form like:
Partitions and qualified values
Problem with repeated properties
Example: Books have two IDs (an isbn and an internal code)
:Book a sh:Shape ;
sh:property [
sh:predicate schema:productID ;
sh:minCount 1;
sh:datatype xsd:string ;
sh:pattern "^isbn"
];
sh:property [
sh:predicate schema:productID ;
sh:minCount 1;
sh:datatype xsd:string ;
sh:pattern "^code"
] .
:b1 schema:productID "isbn:123-456-789" ;
schema:productID "code234" .
It fails!!
Try it: http://goo.gl/x7oHpi
Partitions and qualified value shapes
Qualified value shapes verify that certain number of values of a given
property have a given shape
:Book a sh:Shape ;
sh:property [
sh:predicate schema:productID ;
sh:minCount 2; sh:maxCount 2; ];
sh:property [
sh:predicate schema:productID ;
sh:qualifiedMinCount 1 ;
sh:qualifiedValueShape [
sh:constraint [sh:pattern "^isbn" ]]];
sh:property [
sh:predicate schema:productID ;
sh:qualifiedMinCount 1 ;
sh:qualifiedValueShape [
sh:constraint [ sh:pattern "^code" ; ]]];
.
Try it: http://goo.gl/v6Zffe
Partitions and qualified value shapes
partition declares a partition on the set of values
:Book a sh:Shape ;
sh:property [
sh:predicate schema:productID ;
sh:partition (
[sh:minCount 1; sh:maxCount 1; sh:pattern "^isbn"]
[sh:minCount 1; sh:maxCount 1; sh:pattern "^code"]
)
] .
Don't try it
Not yet implemented
NOTE:
This feature is under development
The specification defines a Greedy algorithm and the violation errors depend on the order of the elements on the list
This can be tricky when some values overlap several elements in the partition
Filters
Filters limit the nodes that are in scope to those that satisfy the filter
Similar to: "if <filter> then ..."
Try it: http://goo.gl/vadFMk
:User a sh:Shape ;
sh:scopeClass schema:Person ;
sh:filterShape [
a sh:Shape ; # Optional triple
sh:property [
sh:predicate schema:worksFor ;
sh:hasValue :OurCompany ;
]
] ;
sh:property [
sh:predicate schema:url ;
sh:stem "http://ourcompany.org/" ;
] .
:alice a schema:Person ;
schema:worksFor :OurCompany ;
schema:url <http://ourcompany.org/alice> .
:bob a schema:Person ;
schema:worksFor :OurCompany ;
schema:url <http://othercompany.org/bob> .
:carol a schema:Person ;
schema:worksFor :OtherCompany ;
schema:url <http://othercompany.org/carol> .

SPARQL constraints
Constraints based on SPARQL code.
The query returns validation errors
Constraint Description
SPARQLConstraint Type of constraints that will be considered as SPARQL constraints
message Message in case of error
sparql SPARQL code to be executed
prefix Declare reusable prefix
SPARQL constraints
Special variables are used to bind values between SHACL and
SPARQL processors
Constraint Description
$this Focus Node
$shapesGraph Can be used to query the shapes graph
$currentShape Current validated shape
SPARQL constraints
Mappings between result rows and error validation information
Constraint Description
sh:focusNode Value of $this variable
sh:subject Value of ?subject variable
sh:predicate Value of ?predicate variable
sh:object Value of ?object variable
sh:message Value of ?message variable
sh:sourceConstraint The constraint that was validated against
sh:sourceShape The shape that was validated against
sh:severity sh:ViolationError by default or the value of sh:severity
Extension mechanism
SHACL offers an extension mechanism based on SPARQL
In principle, it should be possible to add other mechanisms
<http://www.w3.org/2000/01/rdf-schema#> sh:prefix "rdfs" .
:SpanishLabelsShape a sh:Shape ;
sh:constraint [
a sh:SPARQLConstraint ;
sh:message "Values must be literals with Spanish language tag." ;
sh:sparql """SELECT $this ($this AS ?subject)
(rdfs:label AS ?predicate)
(?value AS ?object)
WHERE { $this rdfs:label ?value .
FILTER (!isLiteral(?value) || !langMatches(lang(?value), "es"))""" ;
] .
Try it: http://goo.gl/Wf1Lxn
Other features
Several features are currently under discussion
SPARQL scopes and SPARQL functions
Extension mechanism for other languages
Recursion
User-friendly syntax

More Related Content

What's hot

One Ontology, One Data Set, Multiple Shapes with SHACL
One Ontology, One Data Set, Multiple Shapes with SHACLOne Ontology, One Data Set, Multiple Shapes with SHACL
One Ontology, One Data Set, Multiple Shapes with SHACL
Connected Data World
 
Jena – A Semantic Web Framework for Java
Jena – A Semantic Web Framework for JavaJena – A Semantic Web Framework for Java
Jena – A Semantic Web Framework for Java
Aleksander Pohl
 
An overview of Neo4j Internals
An overview of Neo4j InternalsAn overview of Neo4j Internals
An overview of Neo4j Internals
Tobias Lindaaker
 

What's hot (20)

Eclipse RDF4J - Working with RDF in Java
Eclipse RDF4J - Working with RDF in JavaEclipse RDF4J - Working with RDF in Java
Eclipse RDF4J - Working with RDF in Java
 
LinkML Intro July 2022.pptx PLEASE VIEW THIS ON ZENODO
LinkML Intro July 2022.pptx PLEASE VIEW THIS ON ZENODOLinkML Intro July 2022.pptx PLEASE VIEW THIS ON ZENODO
LinkML Intro July 2022.pptx PLEASE VIEW THIS ON ZENODO
 
SPARQL 사용법
SPARQL 사용법SPARQL 사용법
SPARQL 사용법
 
RDFS In A Nutshell V1
RDFS In A Nutshell V1RDFS In A Nutshell V1
RDFS In A Nutshell V1
 
RDF, SPARQL and Semantic Repositories
RDF, SPARQL and Semantic RepositoriesRDF, SPARQL and Semantic Repositories
RDF, SPARQL and Semantic Repositories
 
ShEx by Example
ShEx by ExampleShEx by Example
ShEx by Example
 
Introduction To RDF and RDFS
Introduction To RDF and RDFSIntroduction To RDF and RDFS
Introduction To RDF and RDFS
 
LinkML presentation to Yosemite Group
LinkML presentation to Yosemite GroupLinkML presentation to Yosemite Group
LinkML presentation to Yosemite Group
 
SPARQL in a nutshell
SPARQL in a nutshellSPARQL in a nutshell
SPARQL in a nutshell
 
One Ontology, One Data Set, Multiple Shapes with SHACL
One Ontology, One Data Set, Multiple Shapes with SHACLOne Ontology, One Data Set, Multiple Shapes with SHACL
One Ontology, One Data Set, Multiple Shapes with SHACL
 
Introduction to RDF
Introduction to RDFIntroduction to RDF
Introduction to RDF
 
The Semantic Web #9 - Web Ontology Language (OWL)
The Semantic Web #9 - Web Ontology Language (OWL)The Semantic Web #9 - Web Ontology Language (OWL)
The Semantic Web #9 - Web Ontology Language (OWL)
 
An Introduction to SPARQL
An Introduction to SPARQLAn Introduction to SPARQL
An Introduction to SPARQL
 
Jena – A Semantic Web Framework for Java
Jena – A Semantic Web Framework for JavaJena – A Semantic Web Framework for Java
Jena – A Semantic Web Framework for Java
 
RDF and OWL
RDF and OWLRDF and OWL
RDF and OWL
 
Introduction to Apache Spark
Introduction to Apache SparkIntroduction to Apache Spark
Introduction to Apache Spark
 
An overview of Neo4j Internals
An overview of Neo4j InternalsAn overview of Neo4j Internals
An overview of Neo4j Internals
 
SPARQL-DL - Theory & Practice
SPARQL-DL - Theory & PracticeSPARQL-DL - Theory & Practice
SPARQL-DL - Theory & Practice
 
Programming the Semantic Web
Programming the Semantic WebProgramming the Semantic Web
Programming the Semantic Web
 
ESWC 2017 Tutorial Knowledge Graphs
ESWC 2017 Tutorial Knowledge GraphsESWC 2017 Tutorial Knowledge Graphs
ESWC 2017 Tutorial Knowledge Graphs
 

Similar to SHACL by example

Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
Péter Király
 
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
Alasdair Gray
 

Similar to SHACL by example (20)

Part04_SHACL By Example presentation.pptx
Part04_SHACL By Example presentation.pptxPart04_SHACL By Example presentation.pptx
Part04_SHACL By Example presentation.pptx
 
SHACL Specification Draft
SHACL Specification DraftSHACL Specification Draft
SHACL Specification Draft
 
RDF data validation 2017 SHACL
RDF data validation 2017 SHACLRDF data validation 2017 SHACL
RDF data validation 2017 SHACL
 
Challenges and applications of RDF shapes
Challenges and applications of RDF shapesChallenges and applications of RDF shapes
Challenges and applications of RDF shapes
 
SHACL shortly (ELAG 2018)
SHACL shortly (ELAG 2018)SHACL shortly (ELAG 2018)
SHACL shortly (ELAG 2018)
 
Optimizing SPARQL Queries with SHACL.pdf
Optimizing SPARQL Queries with SHACL.pdfOptimizing SPARQL Queries with SHACL.pdf
Optimizing SPARQL Queries with SHACL.pdf
 
Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
Validating JSON, XML and CSV data with SHACL-like constraints (DINI-KIM 2022)
 
RDF SHACL, Annotations, and Data Frames
RDF SHACL, Annotations, and Data FramesRDF SHACL, Annotations, and Data Frames
RDF SHACL, Annotations, and Data Frames
 
JSON-LD Update
JSON-LD UpdateJSON-LD Update
JSON-LD Update
 
Graph databases & data integration v2
Graph databases & data integration v2Graph databases & data integration v2
Graph databases & data integration v2
 
What’s in a structured value?
What’s in a structured value?What’s in a structured value?
What’s in a structured value?
 
Validating and Describing Linked Data Portals using RDF Shape Expressions
Validating and Describing Linked Data Portals using RDF Shape ExpressionsValidating and Describing Linked Data Portals using RDF Shape Expressions
Validating and Describing Linked Data Portals using RDF Shape Expressions
 
SPIN and Shapes
SPIN and ShapesSPIN and Shapes
SPIN and Shapes
 
20th Feb 2020 json-ld-rdf-im-proposal.pdf
20th Feb 2020 json-ld-rdf-im-proposal.pdf20th Feb 2020 json-ld-rdf-im-proposal.pdf
20th Feb 2020 json-ld-rdf-im-proposal.pdf
 
JSON-LD update DC 2017
JSON-LD update DC 2017JSON-LD update DC 2017
JSON-LD update DC 2017
 
HyperGraphQL
HyperGraphQLHyperGraphQL
HyperGraphQL
 
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
Tutorial: Describing Datasets with the Health Care and Life Sciences Communit...
 
Two graph data models : RDF and Property Graphs
Two graph data models : RDF and Property GraphsTwo graph data models : RDF and Property Graphs
Two graph data models : RDF and Property Graphs
 
Native XML processing in C++ (BoostCon'11)
Native XML processing in C++ (BoostCon'11)Native XML processing in C++ (BoostCon'11)
Native XML processing in C++ (BoostCon'11)
 
Rdf data-model-and-storage
Rdf data-model-and-storageRdf data-model-and-storage
Rdf data-model-and-storage
 

More from Jose Emilio Labra Gayo

More from Jose Emilio Labra Gayo (20)

Publicaciones de investigación
Publicaciones de investigaciónPublicaciones de investigación
Publicaciones de investigación
 
Introducción a la investigación/doctorado
Introducción a la investigación/doctoradoIntroducción a la investigación/doctorado
Introducción a la investigación/doctorado
 
Legislative data portals and linked data quality
Legislative data portals and linked data qualityLegislative data portals and linked data quality
Legislative data portals and linked data quality
 
Validating RDF data: Challenges and perspectives
Validating RDF data: Challenges and perspectivesValidating RDF data: Challenges and perspectives
Validating RDF data: Challenges and perspectives
 
Wikidata
WikidataWikidata
Wikidata
 
Legislative document content extraction based on Semantic Web technologies
Legislative document content extraction based on Semantic Web technologiesLegislative document content extraction based on Semantic Web technologies
Legislative document content extraction based on Semantic Web technologies
 
Introduction to SPARQL
Introduction to SPARQLIntroduction to SPARQL
Introduction to SPARQL
 
Introducción a la Web Semántica
Introducción a la Web SemánticaIntroducción a la Web Semántica
Introducción a la Web Semántica
 
RDF Data Model
RDF Data ModelRDF Data Model
RDF Data Model
 
2017 Tendencias en informática
2017 Tendencias en informática2017 Tendencias en informática
2017 Tendencias en informática
 
RDF, linked data and semantic web
RDF, linked data and semantic webRDF, linked data and semantic web
RDF, linked data and semantic web
 
Introduction to SPARQL
Introduction to SPARQLIntroduction to SPARQL
Introduction to SPARQL
 
19 javascript servidor
19 javascript servidor19 javascript servidor
19 javascript servidor
 
Como publicar datos: hacia los datos abiertos enlazados
Como publicar datos: hacia los datos abiertos enlazadosComo publicar datos: hacia los datos abiertos enlazados
Como publicar datos: hacia los datos abiertos enlazados
 
16 Alternativas XML
16 Alternativas XML16 Alternativas XML
16 Alternativas XML
 
XSLT
XSLTXSLT
XSLT
 
XPath
XPathXPath
XPath
 
Arquitectura de la Web y Computación en el Servidor
Arquitectura de la Web y Computación en el ServidorArquitectura de la Web y Computación en el Servidor
Arquitectura de la Web y Computación en el Servidor
 
RDF Validation Future work and applications
RDF Validation Future work and applicationsRDF Validation Future work and applications
RDF Validation Future work and applications
 
RDF data model
RDF data modelRDF data model
RDF data model
 

Recently uploaded

Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
drjose256
 

Recently uploaded (20)

Filters for Electromagnetic Compatibility Applications
Filters for Electromagnetic Compatibility ApplicationsFilters for Electromagnetic Compatibility Applications
Filters for Electromagnetic Compatibility Applications
 
Raashid final report on Embedded Systems
Raashid final report on Embedded SystemsRaashid final report on Embedded Systems
Raashid final report on Embedded Systems
 
Artificial Intelligence Bayesian Reasoning
Artificial Intelligence Bayesian ReasoningArtificial Intelligence Bayesian Reasoning
Artificial Intelligence Bayesian Reasoning
 
Research Methodolgy & Intellectual Property Rights Series 1
Research Methodolgy & Intellectual Property Rights Series 1Research Methodolgy & Intellectual Property Rights Series 1
Research Methodolgy & Intellectual Property Rights Series 1
 
Research Methodolgy & Intellectual Property Rights Series 2
Research Methodolgy & Intellectual Property Rights Series 2Research Methodolgy & Intellectual Property Rights Series 2
Research Methodolgy & Intellectual Property Rights Series 2
 
"United Nations Park" Site Visit Report.
"United Nations Park" Site  Visit Report."United Nations Park" Site  Visit Report.
"United Nations Park" Site Visit Report.
 
Operating System chapter 9 (Virtual Memory)
Operating System chapter 9 (Virtual Memory)Operating System chapter 9 (Virtual Memory)
Operating System chapter 9 (Virtual Memory)
 
Introduction to Heat Exchangers: Principle, Types and Applications
Introduction to Heat Exchangers: Principle, Types and ApplicationsIntroduction to Heat Exchangers: Principle, Types and Applications
Introduction to Heat Exchangers: Principle, Types and Applications
 
Introduction to Artificial Intelligence and History of AI
Introduction to Artificial Intelligence and History of AIIntroduction to Artificial Intelligence and History of AI
Introduction to Artificial Intelligence and History of AI
 
Multivibrator and its types defination and usges.pptx
Multivibrator and its types defination and usges.pptxMultivibrator and its types defination and usges.pptx
Multivibrator and its types defination and usges.pptx
 
Lesson no16 application of Induction Generator in Wind.ppsx
Lesson no16 application of Induction Generator in Wind.ppsxLesson no16 application of Induction Generator in Wind.ppsx
Lesson no16 application of Induction Generator in Wind.ppsx
 
Involute of a circle,Square, pentagon,HexagonInvolute_Engineering Drawing.pdf
Involute of a circle,Square, pentagon,HexagonInvolute_Engineering Drawing.pdfInvolute of a circle,Square, pentagon,HexagonInvolute_Engineering Drawing.pdf
Involute of a circle,Square, pentagon,HexagonInvolute_Engineering Drawing.pdf
 
Software Engineering - Modelling Concepts + Class Modelling + Building the An...
Software Engineering - Modelling Concepts + Class Modelling + Building the An...Software Engineering - Modelling Concepts + Class Modelling + Building the An...
Software Engineering - Modelling Concepts + Class Modelling + Building the An...
 
Interfacing Analog to Digital Data Converters ee3404.pdf
Interfacing Analog to Digital Data Converters ee3404.pdfInterfacing Analog to Digital Data Converters ee3404.pdf
Interfacing Analog to Digital Data Converters ee3404.pdf
 
Instruct Nirmaana 24-Smart and Lean Construction Through Technology.pdf
Instruct Nirmaana 24-Smart and Lean Construction Through Technology.pdfInstruct Nirmaana 24-Smart and Lean Construction Through Technology.pdf
Instruct Nirmaana 24-Smart and Lean Construction Through Technology.pdf
 
NEWLETTER FRANCE HELICES/ SDS SURFACE DRIVES - MAY 2024
NEWLETTER FRANCE HELICES/ SDS SURFACE DRIVES - MAY 2024NEWLETTER FRANCE HELICES/ SDS SURFACE DRIVES - MAY 2024
NEWLETTER FRANCE HELICES/ SDS SURFACE DRIVES - MAY 2024
 
How to Design and spec harmonic filter.pdf
How to Design and spec harmonic filter.pdfHow to Design and spec harmonic filter.pdf
How to Design and spec harmonic filter.pdf
 
Theory for How to calculation capacitor bank
Theory for How to calculation capacitor bankTheory for How to calculation capacitor bank
Theory for How to calculation capacitor bank
 
Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
Tembisa Central Terminating Pills +27838792658 PHOMOLONG Top Abortion Pills F...
 
AI in Healthcare Innovative use cases and applications.pdf
AI in Healthcare Innovative use cases and applications.pdfAI in Healthcare Innovative use cases and applications.pdf
AI in Healthcare Innovative use cases and applications.pdf
 

SHACL by example

  • 1. SHACL by example RDF Validation tutorial Eric Prud'hommeaux World Wide Web Consortium MIT, Cambridge, MA, USA Harold Solbrig Mayo Clinic, USA Jose Emilio Labra Gayo WESO Research group University of Oviedo, Spain Iovka Boneva LINKS, INRIA & CNRS University of Lille, France
  • 2. SHACL W3c Data Shapes WG deliverable https://www.w3.org/TR/shacl/ Inspired by SPIN, OSLC & bits of ShEx SPARQL based extension mechanism RDF vocabulary Human friendly syntax inspired by ShEx proposed as a WG Note * * https://w3c.github.io/data-shapes/shacl-compact-syntax/
  • 3. Some definitions about SHACL Shape: collection of targets and constraints components Targets: specify which nodes in the data graph must conform to a shape Constraint components: Determine how to validate a node Shapes graph: an RDF graph that contains shapes Data graph: an RDF graph that contains data to be validated
  • 4. Example Try it. RDFShape http://goo.gl/FqXQpD prefix : <http://example.org/> prefix sh: <http://www.w3.org/ns/shacl#> prefix xsd: <http://www.w3.org/2001/XMLSchema#> prefix schema: <http://schema.org/> :UserShape a sh:NodeShape ; sh:targetNode :alice, :bob, :carol ; sh:property [ sh:path schema:name ; sh:minCount 1; sh:maxCount 1; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:email ; sh:minCount 1; sh:maxCount 1; sh:nodeKind sh:IRI ; ] . :alice schema:name "Alice Cooper" ; schema:email <mailto:alice@mail.org> . :bob schema:firstName "Bob" ; schema:email <mailto:bob@mail.org> . :carol schema:name "Carol" ; schema:email "carol@mail.org" . Shapes graph Data graph  
  • 5. Target declarations Targets specify nodes that must be validated against the shape Several types Value Description targetNode Directly point to a node targetClass All nodes that have a given type targetProperty All nodes that have a given property target General mechanism based on SPARQL
  • 6. Target node Directly declare which nodes must validate the against the shape :UserShape a sh:NodeShape ; sh:targetNode :alice, :bob, :carol ; sh:property [ sh:path schema:name ; sh:minCount 1; sh:maxCount 1; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:email ; sh:minCount 1; sh:maxCount 1; sh:nodeKind sh:IRI ; ] . :alice schema:name "Alice Cooper" ; schema:email <mailto:alice@mail.org> . :bob schema:givenName "Bob" ; schema:email <mailto:bob@mail.org> . :carol schema:name "Carol" ; schema:email "carol@mail.org" .
  • 7. Target class Selects all nodes that have a given type Looks for rdf:type declarations* * Also looks for rdfs:subClassOf*/rdf:type declarations :UserShape a sh:NodeShape ; sh:targetClass :User ; sh:property [ sh:path schema:name ; sh:minCount 1; sh:maxCount 1; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:email ; sh:minCount 1; sh:maxCount 1; sh:nodeKind sh:IRI ; ] . :alice a :User; schema:name "Alice Cooper" ; schema:email <mailto:alice@mail.org> . :bob a :User; schema:givenName "Bob" ; schema:email <mailto:bob@mail.org> . :carol a :User; schema:name "Carol" ; schema:email "carol@mail.org" .
  • 8. Implicit target class A shape with type sh:Shape and rdfs:Class is a scope class of itself The targetClass declaration is implicit :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path schema:name ; sh:minCount 1; sh:maxCount 1; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:email ; sh:minCount 1; sh:maxCount 1; sh:nodeKind sh:IRI ; ] . :alice a :User; schema:name "Alice Cooper" ; schema:email <mailto:alice@mail.org> . :bob a :User; schema:givenName "Bob" ; schema:email <mailto:bob@mail.org> . :carol a :User; schema:name "Carol" ; schema:email "carol@mail.org" .
  • 9. Types of shapes Type Description Node shapes Constraints about a given focus node Property shapes Constraints about a property and the values of a path for a node Shape target declarations NodeShape PropertyShape constraint components constraint components sh:path: rdfs:Resource
  • 10. :alice a :User . <http://example.org/bob> a :User . _:1 a :User . Node Shapes Constraints about a focus node  :User a sh:NodeShape ; sh:nodeKind sh:IRI .
  • 11. Property shapes Constraints about a given property and its values for the focus node sh:property associates a shape with a property constraint sh:path identifies the path :User a sh:NodeShape ; sh:property [ sh:path schema:email ; sh:nodeKind sh:IRI ] . :alice a :User ; schema:email <mailto:alice@mail.org> . :bob a :User; schema:email <mailto:bob@mail.org> . :carol a :User; schema:email "carol@mail.org" .  
  • 12. Paths in property shapes Example with inverse path inversePath, zeroOrMorePath, alternativePath, oneOrMorePath, ... :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path [sh:inversePath schema:follows ]; sh:nodeKind sh:IRI ; ] . :alice a :User; schema:follows :bob . :bob a :User . :carol a :User; schema:follows :alice . _:1 schema:follows :bob . 
  • 13. Core constraint components Type Constraints Cardinality minCount, maxCount Types of values class, datatype, nodeKind Values node, in, hasValue Range of values minInclusive, maxInclusive minExclusive, maxExclusive String based minLength, maxLength, pattern, stem, uniqueLang Logical constraints not, and, or, xone Closed shapes closed, ignoredProperties Property pair constraints equals, disjoint, lessThan, lessThanOrEquals Non-validating constraints name, value, defaultValue Qualified shapes qualifiedValueShape, qualifiedMinCount, qualifiedMaxCount
  • 14. Cardinality constraints Constraint Description minCount Restricts minimum number of triples involving the focus node and a given predicate. Default value: 0 maxCount Restricts maximum number of triples involving the focus node and a given predicate. If not defined = unbounded Try it. http://goo.gl/9AwtFK :User a sh:NodeShape ; sh:property [ sh:path schema:follows ; sh:minCount 2 ; sh:maxCount 3 ; ] . :alice schema:follows :bob, :carol . :bob schema:follows :alice . :carol schema:follows :alice, :bob, :carol, :dave .  
  • 15. Datatypes of values Constraint Description datatype Restrict the datatype of all value nodes to a given value :User a sh:NodeShape ; sh:property [ sh:path schema:birthDate ; sh:datatype xsd:date ; ] . Try it: http://goo.gl/eDwxsU :alice schema:birthDate "1985-08-20"^^xsd:date . :bob schema:birthDate "Unknown"^^xsd:date . :carol schema:birthDate 1990 .  
  • 16. Class of values Constraint Description class Verify that each node in an instance of some class It also allows instances of subclasses* (*) The notion of SHACL instance is different from RDFS It is defined as rdfs:subClassOf*/rdf:type :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path schema:follows ; sh:class :User ] . :Manager rdfs:subClassOf :User . :alice a :User; schema:follows :bob . :bob a :Manager ; schema:follows :alice . :carol a :User; schema:follows :alice, :dave . :dave a :Employee . 
  • 17. Kind of values Constraint Description nodeKind Possible values: BlankNode, IRI, Literal, BlankNodeOrIRI, BlankNodeOrLiteral, IRIOrLiteral :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path schema:name ; sh:nodeKind sh:Literal ; ]; sh:property [ sh:path schema:follows ; sh:nodeKind sh:BlankNodeOrIRI ]; sh:nodeKind sh:IRI . :alice a :User; schema:name _:1 ; schema:follows :bob . :bob a :User; schema:name "Robert"; schema:follows [ schema:name "Dave" ] . :carol a :User; schema:name "Carol" ; schema:follows "Dave" . _:1 a :User .   
  • 18. Constraints on values Constraint Description hasValue Verifies that the focus node has a given value in Enumerates the value nodes that a property may have :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path schema:affiliation ; sh:hasValue :OurCompany ; ]; sh:property [ sh:path schema:gender ; sh:in (schema:Male schema:Female) ] . :alice a :User; schema:affiliation :OurCompany ; schema:gender schema:Female . :bob a :User; schema:affiliation :AnotherCompany ; schema:gender schema:Male . :carol a :User; schema:affiliation :OurCompany ; schema:gender schema:Unknown .  
  • 19. Constraints on values with another shape Constraint Description node* All values of a given property must have a given shape Recursion is not allowed in current SHACL :User a sh:NodeShape, rdfs:Class ; sh:property [ sh:path schema:worksFor ; sh:node :Company ; ] . :Company a sh:Shape ; sh:property [ sh:path schema:name ; sh:datatype xsd:string ; ] . :alice a :User; schema:worksFor :OurCompany . :bob a :User; schema:worksFor :Another . :OurCompany schema:name "OurCompany" . :Another schema:name 23 .  *recently renamed as sh:shape
  • 20. Value shapes and recursion Could we define cyclic data models as the following? :User a sh:NodeShape ; sh:property [ sh:path schema:worksFor ; sh:node :Company ; ] . :Company a sh:Shape ; sh:property [ sh:path schema:name ; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:employee ; sh:node :User ; ] . :User :Company schema:name xsd:string schema:worksFor schema:employee No, current SHACL specification doesn't allow this :alice schema:worksFor :OneCompany . :bob schema:worksFor :OneCompany . :carol schema:worksFor :OneCompany . :OneCompany schema:name "One" ; schema:employee :alice, :bob, :carol . Don't try it 
  • 21. SHACL approach to avoid recursion Add rdf:type arcs for every resource and use sh:class :User a sh:NodeShape ; sh:property [ sh:path schema:worksFor ; sh:class :Company ; ] . :Company a sh:Shape ; sh:property [ sh:path schema:name ; sh:datatype xsd:string ; ] ; sh:property [ sh:path schema:employee ; sh:class :User ; ] . :User :Company schema:name xsd:string schema:worksFor schema:employee Try it: http://goo.gl/wlVZJR :alice a :User ; schema:worksFor :OneCompany . :bob a :User ; schema:worksFor :OneCompany . :carol a :User ; schema:worksFor :Something . :OneCompany a :Company ; schema:name "One" ; schema:employee :alice, :bob, :carol . 
  • 22. Logical Operators Constraint Description and Conjunction of a list of shapes or Disjunction of a list of shapes not Negation of a shape xone Exactly one (similar XOR for 2 arguments)
  • 23. and Default behavior :User a sh:NodeShape ; sh:and ( [ sh:property [ sh:path schema:name; sh:minCount 1; ] ] [ sh:property [ sh:path schema:affiliation; sh:minCount 1; ] ] ) . :User a sh:Shape ; [ sh:property [ sh:path schema:name; sh:minCount 1; ] ] [ sh:property [ sh:path schema:affiliation; sh:minCount 1; ] ] . ≡
  • 24. or :User a sh:NodeShape ; sh:or ( [ sh:property [ sh:predicate foaf:name; sh:minCount 1; ] ] [ sh:property [ sh:predicate schema:name; sh:minCount 1; ] ] ) . :alice schema:name "Alice" . :bob foaf:name "Robert" . :carol rdfs:label "Carol" . 
  • 25. not :NotFoaf a sh:NodeShape ; sh:not [ a sh:Shape ; sh:property [ sh:predicate foaf:name ; sh:minCount 1 ; ] ; ] . :alice schema:name "Alice" . :bob foaf:name "Robert" . :carol rdfs:label "Carol" . 
  • 27. Value ranges Constraint Description minInclusive maxInclusive minExclusive maxExclusive Try it: http://goo.gl/qnd66j :Rating a sh:NodeShape ; sh:property [ sh:path schema:ratingValue ; sh:minInclusive 1 ; sh:maxInclusive 5 ; sh:datatype xsd:integer ] . :bad schema:ratingValue 1 . :average schema:ratingValue 3 . :veryGood schema:ratingValue 5 . :zero schema:ratingValue 0 .
  • 28. String based constraints Constraint Description minLength Restricts the minimum string length on value nodes maxLength Restricts the maximum string length on value nodes pattern Checks if the string value matches a regular expression stem Checks if all value nodes are IRIs and the IRI starts with a given string value uniqueLang Checks that no pair of nodes use the same language tag
  • 29. minLength/maxLength Try it: http://goo.gl/NrJl83 :User a sh:NodeShape ; sh:property [ sh:path schema:name ; sh:minLength 4 ; sh:maxLength 10 ; ] . :alice schema:name "Alice" . :bob schema:name "Bob" . :carol schema:name :Carol . :strange schema:name _:strange .  Checks the string representation of the value This cannot be applied to blank nodes If minLength = 0, no restriction on string length 
  • 30. pattern Checks if the values matches a regular expression It can be combined with sh:flags :Product a sh:NodeShape ; sh:property [ sh:path schema:productID ; sh:pattern "^Pd{3,4}" ; sh:flags "i" ; ] . :car schema:productID "P2345" . :bus schema:productID "p567" . :truck schema:productID "P12" . :bike schema:productID "B123" .   Try it: http://goo.gl/BsHpqu
  • 31. uniqueLang Checks that no pair of nodes use the same language tag Try it: http://goo.gl/B1PNcO :Country a sh:NodeShape ; sh:property [ sh:path schema:name ; sh:uniqueLang true ] . :spain schema:name "Spain"@en, "España"@es . :france schema:name "France"@en, "Francia"@es . :usa schema:name "USA"@en, "United States"@en. 
  • 32. Property pair constraints Constraint Description equals The sets of values of both properties at a given focus node must be equal disjoint The sets of values of both properties at a given focus node must be different lessThan The values must be smaller than the values of another property lessThanOrEquals The values must be smaller or equal than the values of another property Try it: http://goo.gl/BFzMoz :User a sh:NodeShape ; sh:property [ sh:path schema:givenName ; sh:equals foaf:firstName ]; sh:property [ sh:path schema:givenName ; sh:disjoint schema:lastName ] . :alice schema:givenName "Alice"; schema:lastName "Cooper"; foaf:firstName "Alice" . :bob schema:givenName "Bob"; schema:lastName "Smith" ; foaf:firstName "Robert" . :carol schema:givenName "Carol"; schema:lastName "Carol" ; foaf:firstName "Carol" .  
  • 33. Closed shapes Constraint Description closed Valid resources must only have values for properties that appear in sh:property ignoredProperties Optional list of properties that are also permitted :User a sh:NodeShape ; sh:closed true ; sh:ignoredProperties ( rdf:type ) ; sh:property [ sh:path schema:givenName ; ]; sh:property [ sh:path schema:lastName ; ] . :alice schema:givenName "Alice"; schema:lastName "Cooper" . :bob a :Employee ; schema:givenName "Bob"; schema:lastName "Smith" . :carol schema:givenName "Carol"; schema:lastName "King" ; rdfs:label "Carol" .  Try it: http://goo.gl/wcW16o
  • 34. Non-validating constraints Can be useful to annotate shapes or design UI forms Constraint Description name Provide human-readable labels for a property description Provide a description of a property order Relative order of the property group Group several constraints together :User a sh:NodeShape ; sh:property [ sh:path schema:url ; sh:name "URL"; sh:description "User URL"; sh:order 1 ]; sh:property [ sh:path schema:name ; sh:name "Name"; sh:description "User name"; sh:order 2 ] .
  • 35. Non-validating constraints :User a sh:NodeShape ; sh:property [ sh:path schema:url ; sh:name "URL"; sh:group :userDetails ]; sh:property [ sh:path schema:name ; sh:name "Name"; sh:group :userDetails ]; sh:property [ sh:path schema:address ; sh:name "Address"; sh:group :location ]; sh:property [ sh:path schema:country ; sh:name "Country"; sh:group :location ] . :userDetails a sh:PropertyGroup ; sh:order 0 ; rdfs:label "User details" . :location a sh:PropertyGroup ; sh:order 1 ; rdfs:label "Location" . User details URL: _____________________ Name: ___________________ Location Address: __________________ Country: __________________ An agent could generate a form like:
  • 36. Partitions and qualified values Problem with repeated properties Example: Books have two IDs (an isbn and an internal code) :Book a sh:Shape ; sh:property [ sh:predicate schema:productID ; sh:minCount 1; sh:datatype xsd:string ; sh:pattern "^isbn" ]; sh:property [ sh:predicate schema:productID ; sh:minCount 1; sh:datatype xsd:string ; sh:pattern "^code" ] . :b1 schema:productID "isbn:123-456-789" ; schema:productID "code234" . It fails!! Try it: http://goo.gl/x7oHpi
  • 37. Partitions and qualified value shapes Qualified value shapes verify that certain number of values of a given property have a given shape :Book a sh:Shape ; sh:property [ sh:predicate schema:productID ; sh:minCount 2; sh:maxCount 2; ]; sh:property [ sh:predicate schema:productID ; sh:qualifiedMinCount 1 ; sh:qualifiedValueShape [ sh:constraint [sh:pattern "^isbn" ]]]; sh:property [ sh:predicate schema:productID ; sh:qualifiedMinCount 1 ; sh:qualifiedValueShape [ sh:constraint [ sh:pattern "^code" ; ]]]; . Try it: http://goo.gl/v6Zffe
  • 38. Partitions and qualified value shapes partition declares a partition on the set of values :Book a sh:Shape ; sh:property [ sh:predicate schema:productID ; sh:partition ( [sh:minCount 1; sh:maxCount 1; sh:pattern "^isbn"] [sh:minCount 1; sh:maxCount 1; sh:pattern "^code"] ) ] . Don't try it Not yet implemented NOTE: This feature is under development The specification defines a Greedy algorithm and the violation errors depend on the order of the elements on the list This can be tricky when some values overlap several elements in the partition
  • 39. Filters Filters limit the nodes that are in scope to those that satisfy the filter Similar to: "if <filter> then ..." Try it: http://goo.gl/vadFMk :User a sh:Shape ; sh:scopeClass schema:Person ; sh:filterShape [ a sh:Shape ; # Optional triple sh:property [ sh:predicate schema:worksFor ; sh:hasValue :OurCompany ; ] ] ; sh:property [ sh:predicate schema:url ; sh:stem "http://ourcompany.org/" ; ] . :alice a schema:Person ; schema:worksFor :OurCompany ; schema:url <http://ourcompany.org/alice> . :bob a schema:Person ; schema:worksFor :OurCompany ; schema:url <http://othercompany.org/bob> . :carol a schema:Person ; schema:worksFor :OtherCompany ; schema:url <http://othercompany.org/carol> . 
  • 40. SPARQL constraints Constraints based on SPARQL code. The query returns validation errors Constraint Description SPARQLConstraint Type of constraints that will be considered as SPARQL constraints message Message in case of error sparql SPARQL code to be executed prefix Declare reusable prefix
  • 41. SPARQL constraints Special variables are used to bind values between SHACL and SPARQL processors Constraint Description $this Focus Node $shapesGraph Can be used to query the shapes graph $currentShape Current validated shape
  • 42. SPARQL constraints Mappings between result rows and error validation information Constraint Description sh:focusNode Value of $this variable sh:subject Value of ?subject variable sh:predicate Value of ?predicate variable sh:object Value of ?object variable sh:message Value of ?message variable sh:sourceConstraint The constraint that was validated against sh:sourceShape The shape that was validated against sh:severity sh:ViolationError by default or the value of sh:severity
  • 43. Extension mechanism SHACL offers an extension mechanism based on SPARQL In principle, it should be possible to add other mechanisms <http://www.w3.org/2000/01/rdf-schema#> sh:prefix "rdfs" . :SpanishLabelsShape a sh:Shape ; sh:constraint [ a sh:SPARQLConstraint ; sh:message "Values must be literals with Spanish language tag." ; sh:sparql """SELECT $this ($this AS ?subject) (rdfs:label AS ?predicate) (?value AS ?object) WHERE { $this rdfs:label ?value . FILTER (!isLiteral(?value) || !langMatches(lang(?value), "es"))""" ; ] . Try it: http://goo.gl/Wf1Lxn
  • 44. Other features Several features are currently under discussion SPARQL scopes and SPARQL functions Extension mechanism for other languages Recursion User-friendly syntax