Defining custom SHACL shapes (validation)

SHACL (Shapes Constraint Language) files are stored in your configured shapes/ directory. They validate that your page frontmatter is structurally correct.

To create a custom constraint for a class (e.g., a Project class):

1. Create a file named shapes/project-shape.ttl.
2. Define a sh:NodeShape that targets your class and specifies property constraints:

@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix schema: <https://schema.org/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix wiki: <https://wazootech.github.io/wiki/wiki/> .

schema:ProjectShape a sh:NodeShape ;
  sh:targetClass schema:Project ;
  
  # Required properties
  sh:property [
    sh:path schema:name ;
    sh:minCount 1 ;
    sh:maxCount 1 ;
    sh:datatype xsd:string ;
    sh:message "Project must have exactly one name string." ;
  ] ;
  
  sh:property [
    sh:path schema:startDate ;
    sh:minCount 1 ;
    sh:maxCount 1 ;
    sh:datatype xsd:date ;
    sh:message "Project must have a startDate in YYYY-MM-DD format." ;
  ] .

When you run wiki check, any page with type: Project is automatically validated against these constraints!