AL : NodeType

An important feature of many repositories is the ability to distinguish the entities stored in the repository by type.
Node types are used to enforce structural restrictions on the nodes and properties in a workspace by defining for each node, its required and permitted child nodes and properties.

Every node has one declared node type. node types are typically used to defined the core characteristics of
a node. In a writable repository a node's primary type is first assigned upon node creation.

Repository implementations may vary as to how flexible they are in allowing changes to the node types assigned to a node. Each repository has a single, system-wide registry of node types. Typically, a repository will come with some implementation-determined set of built-in node types.

Some of these types may be vendor-specific while others may be standard predefined node types defined. Some repositories may further allow users to register new node types programmatically


A node type definition consists of the following attributes:


NodeTypeId

Every registered node type has a name, unique within the repository. NodeTypeId consists of prefix of AnotherLore URI and short local name in a workspace




Supertypes

A node type has zero or one supertype. Supertypes are specified by name. The supertype relation is transitive: If T1 is a supertype of T2 and T2 is a supertype of T3 then T1 is a supertype of T3.



Property Definitions

A node type may contain a list of property definitions, which specify the properties that nodes of that type are permitted or required to have and the characteristics of those properties. The list of property definitions may be empty.


Orderable Member NodeType

A node type may declare its member type orderable, meaning that for all nodes of that type, the order that the member nodes are iterated over can be programmatically controlled by the user. A node type may contain a list of member node definitions, which specify the permitted or required child nodes and their characteristics. member type definitions may be empty. if not setted, in principle have objectType(objectType have no propertyDefinition and is supertype of all nodetype)


Mapping Property Definition

The default values attribute of a property definition defines the values assigned to property if it is auto-created. If the property is single-valued this attribute will hold a single value.

A property definition may impose constraints on the value that the property may hold. These value constraints are defined by an array of strings, whose format differs depending on the type of the property.


[example Code]

NodeType commentType = globalStore.createNodeType(objectType, "comment", new PropertyDefinition[] { comment, regUserId, regDate });
  commentType.setConstraint(COMMENT, new RangeByteLengthConstraint(10, 4000));
  commentType.setConstraint(REGUSERID, new RequireConstraint());
  commentType.setConstraint(REGDATE, new RequireConstraint());      // set constraint
  commentType.setDefaultValue(REGDATE, new CurrentDateValue()) ;  // set default



<Inteface NodeType extends Serializable, Publishable>

 public NodeType setConstraint(IDString propId, IValueConstraint constraint)  throws RepositoryException ;
 public NodeType setDefaultValue(IDString propId, IDefaultValue defaultValue)  throws RepositoryException ;
 public NodeTypeId getId() ;
 public NodeType getSuperType()  throws RepositoryException ;
 public void setMemberType(NodeType memberType)  throws RepositoryException ; 
 public NodeType getMemberType()  throws RepositoryException ;
 public boolean isAllowedMemberType(NodeType memberType)  throws RepositoryException ;
 public GenericIterator<MappedDefinition> getMappedDefinitions() throws RepositoryException;
 public MappedDefinition getMappedDefinition(IDString propId) throws RepositoryException ;
 public boolean containsPropId(IDString propId)  throws RepositoryException ;
 public boolean isNodeType(NodeType thatType)  throws RepositoryException ;
 public boolean isNodeType(String thatTypeId)  throws RepositoryException ;
 public GenericIterator<ValidMessage> getViolateConstraintMessage(Node node) throws RepositoryException;