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Organizes links

A folder or a list often points at nodes that live elsewhere: a ListToRestrict folder that gathers the settings an operator may change, a Shortcuts folder on a panel. In OPC UA each of those is an Organizes reference from the folder to the node. A references: entry says it, but it takes a referenceType, a source and a target per link, each a path.

Under organizes:, a string item is such a link: an Organizes reference from the entry that holds the list to the node the string names. An object item keeps its meaning: it declares a child (see A folder a type organizes). Both may be mixed in one list.

In a type: $Name​

A folder that organizes two members of its type
objectTypes:
  - browseName: ControllerType
    components:
      - browseName: Settings
        typeDefinition: ua:BaseObjectType
        components:
          - browseName: Speed
            dataType: ua:Double
          - browseName: MaxAcceleration
            dataType: ua:Double
      - browseName: ListToRestrict
        typeDefinition: ua:FolderType
        organizes: [$Speed, $MaxAcceleration]

Inside a type, $Name is the member of that type whose BrowseName is Name, at any depth: here Settings/Speed, without spelling the path. The compiler looks at the members the type declares first; only when none has the name does it look at the members the type inherits from its supertypes and the interfaces they implement (an Optional interface member, which the type does not copy, included).

It is the same NodeSet as the long form:

The same links as references: entries
objectTypes:
  - browseName: ControllerType
    components:
      - browseName: Settings
        typeDefinition: ua:BaseObjectType
        components:
          - browseName: Speed
            dataType: ua:Double
          - browseName: MaxAcceleration
            dataType: ua:Double
      - browseName: ListToRestrict
        typeDefinition: ua:FolderType
    references:
      - referenceType: ua:Organizes
        source: /ListToRestrict
        target: /Settings/Speed
      - referenceType: ua:Organizes
        source: /ListToRestrict
        target: /Settings/MaxAcceleration

The links belong to the type, so every instance of it gets them between its own copies of the members.

An inherited member​

Organizing a member the type inherits
objectTypes:
  - browseName: AxisType
    components:
      - browseName: Speed
        dataType: ua:Double
  - browseName: LinearAxisType
    subtypeOf: AxisType
    components:
      - browseName: Limits
        typeDefinition: ua:FolderType
        organizes: [$Speed]

LinearAxisType declares no Speed, so $Speed is the one it inherits from AxisType.

When the name is not enough​

Two members of the same type may share a BrowseName: each axis of a robot has a Speed. $Speed is then an error, DSL-E-LINK-001, that lists the candidates with their paths. Say which one you mean with its path from the type, or give it a name with $anchor:

A path, or an anchor, when the BrowseName is ambiguous
objectTypes:
  - browseName: RobotType
    components:
      - browseName: Axis1
        typeDefinition: ua:BaseObjectType
        components:
          - browseName: Speed
            dataType: ua:Double
      - browseName: Axis2
        typeDefinition: ua:BaseObjectType
        components:
          - browseName: Speed
            $anchor: Axis2Speed
            dataType: ua:Double
      - browseName: Limits
        typeDefinition: ua:FolderType
        organizes:
          - /Axis1/Speed
          - $Axis2Speed

In a type, a path that starts with / starts at the type, wherever the entry that holds the link sits. A name that matches no member is DSL-E-LINK-002.

Outside types​

On an instance, a string item is a browse path as anywhere else: $Name is an instance (its $anchor, or its BrowseName), and / is the entry that holds the list. The instance may be declared further down.

A folder of shortcuts to other instances
instances:
  - browseName: Shortcuts
    typeDefinition: ua:FolderType
    organizedBy: /ua:Objects
    organizes: [$Machine]
  - browseName: Machine
    typeDefinition: ua:BaseObjectType
    organizedBy: /ua:Objects

Other reference types​

Only Organizes has this short form. Any other reference type is written as a references: entry.

Reversing a NodeSet​

opcua-modeler reverse writes an Organizes reference between two members of a type as a link on the entry of its source: $Name when it names that node unambiguously, its path from the type otherwise. A reference whose source the model does not declare (a member inherited unchanged) stays a references: entry.