JjOM API Reference

The JjOM API provides programmatic access to all elements in the Jjodel Object Model. You can use the API from the Console, within JjEL expressions, in viewpoint templates, and in event handlers.

DClass API

Property	Type	Description
`name`	`String`	Class name
`isAbstract`	`Boolean`	Whether the class is abstract
`isInterface`	`Boolean`	Whether the class is an interface
`isRootable`	`Boolean`	Whether instances can be model roots
`isSingleton`	`Boolean`	Whether only one instance is allowed
`isFinal`	`Boolean`	Whether the class can be extended
`isPrimitive`	`Boolean`	Whether this is a primitive type
`isMetamodel`	`Boolean`	Whether this belongs to the metamodel level
`extends`	`Array<DClass>`	Direct parent classes
`extendedBy`	`Array<DClass>`	Direct subclasses
`attributes`	`Array<DAttribute>`	Owned attributes
`references`	`Array<DReference>`	Owned references
`operations`	`Array<DOperation>`	Owned operations
`features`	`Array<Feature>`	All structural features (attributes + references)
`instances`	`Array<DObject>`	Direct instances of this class
`allInstances`	`Array<DObject>`	All instances, including subclass instances
`packages`	`Array<DPackage>`	Containing packages
`parent`	`*`	Parent element in the containment hierarchy

DObject API

Property	Type	Description
`id`	`Pointer`	Unique identifier
`className`	`String`	Name of the instantiated class
`instanceOf`	`DClass`	The metaclass
`parent`	`*`	Containing element

DAttribute API

Property	Type	Description
`name`	`String`	Attribute name
`type`	`String`	Data type

DReference API

Property	Type	Description
`name`	`String`	Reference name
`target`	`DClass`	Target class
`containment`	`Boolean`	Whether this is a containment reference

DPackage API

Property	Type	Description
`name`	`String`	Package name
`packages`	`Array<DPackage>`	Nested packages
`objects`	`Array<DObject>`	Contained elements

Usage Examples

Querying instances

// All instances of Person (including subclasses)
Person.allInstances

// Filter by attribute value
Person.allInstances.filter(p => p.name === "Alice")

// Count elements
Class.allInstances.length

Navigating the model graph

// From instance to metaclass
myObject.instanceOf.name

// From class to its features
Person.attributes.map(a => a.name)  // → ["name", "age"]

// From class to its subclasses
Entity.extendedBy.map(c => c.name)  // → ["Person", "Organization"]

Checking properties

// Is this class abstract?
myClass.isAbstract  // → true/false

// Can this class be used as a model root?
myClass.isRootable  // → true/false