CreatePHP defines interfaces for the definition of RDF types, properties and collections. Then it defines extended interfaces for types bound to actual values. Think of: type = class, entity = object.
Additionally, type definitions may implement the NodeInterface to expose functionality to render themselves in a DOM-like logic.
The normal workflow is to create the Type, PropertyDefinition and CollectionDefinition instances, configure eventual settings (including Node settings if they implement NodeInterface) and then bind the type to a domain model object with createWithObject. createWithObject returns the Entity for this type bound to the value.
A collection is a list of children entities of an entity. A collection may contain children of different types, but the metadata must specify the allowed child types. In the RDFa model, collections have a couple of attributes:
aboutthe containing subject (can be inherited from containing HTML)relidentifies the HTML element as a container of a collection. The value of therelattribute is irrelevant for create.js and VIE.revif present, defines the attribute to be used on newly created entities in that collection that links back to the containing entity as specified inabout. Createphp uses this to determine the parent entity when persisting a new entity.
To avoid building the type tree with verbose code, there is the Metadata\RdfTypeFactory. It provides TypeInterface instances for given class names. There are several drivers available:
- RdfDriverArray: You pass in an array of configuration when bootstrapping the driver (i.e. through ArrayLoader)
- RdfDriverXml: Reads XML files with configuration, following a naming scheme
- RdfDriverFeelingLucky: Uses introspection to guess at properties. Good for a quick hack, but does not produce meaningful RDF.
Look at the driver phpdoc for the exact syntax to use for configuration.