AL : PropertyDefinition

Property Definitions(속성정의) :
A node type contains a set of definitions specifying the properties that nodes of this node type are allowed (or required) to have and the characteristics of those properties.  A property definition has all the attributes of a generic item definition as well as the following property-specific attributes:

PropertyType

A property definition must specify a property type. Type[String, Binary, Long, Double, Boolean, Date, Name, Text, Reference, Path, ViertualText, Undefined] : defines integer constants for the available property types as well as for their standardized type names (used in serialization) and two methods for converting back and forth between name and integer value:

[Example Code]
 GlobalStore globalStore = session.getGlobalStore() ;
 PropertyDefinition explain = globalStore.createPropertyDefinition(IDString.propId("explain"), Property.Type.STRING) ;
 assertEquals(explain.requiredType(), Property.Type.STRING) ;

 NodeType newType = globalStore.createNodeType(objectType, "temporaryType", new PropertyDefinition[]{explain}) ;
  MappedDefinition md = newType.getMappedDefinition(IDString.propId("explain")) ;
  assertEquals(md.requiredType(), Property.Type.STRING) ;
  assertEquals(1, newType.getMappedDefinitions().size()) ;
  assertEquals("explain", md.getId().getString()) ;




<Inteface PropertyDefinition extends Serializable>
public IDString getId();
public boolean isSameProperty(IDString propId);
public Property.Type requiredType();



PropertyDefinition은 Id와 PropertyType으로 구성되어 있다.


DB의 컬럼과 비슷하기는 하지만 컬럼과 달리 constraint와 defaultValue를 가지지 않는다. 이러한 것들은 NodeType과 Mapping되는 과정에서 추가되고 PropertyDefinition은 단지 해당 아이디를 가진 PropertyDefinition은 특정 Property.Type을 가진다고 정의할 뿐이다.