Meta information

Page contents

• metaInfo property
• MetaInfo composition
• Built-in MetaInfo subclasses

metaInfo property

The library declares metaInfo property for IState and Transition types. MetaInfo is a marker interface allowing to attach some static information to library primitives. This mechanism is extendable and users may add their own MetaInfo sub interfaces/classes if necessary.

MetaInfo considered to be immutable data by design

MetaInfo composition

If you need to specify more than one MetaInfo instance for IState or Transition you have two options:

1. Use CompositeMetaInfo which is constructed by buildCompositeMetaInfo builder function. This composite type allows to specify a set of MetaInfo objects.

   Limitations:

   • CompositeMetaInfo cannot nest into each other. Only one layer is supported.
   • Don’t try to specify MetaInfo of same type multiple times. This is wrong by design. Certain MetaInfo subtype should be applied only once. Exception will be thrown otherwise.

2. Manually implement all required MetaInfo interfaces in a single object.

Both options are supported, choose any one you like more.

Built-in MetaInfo subclasses

• One of standard implementations is UmlMetaInfo which is useful for export feature. See controlling export output. You can build it using buildUmlMetaInfo() function.
• IgnoreUnsafeCallConditionalLambdasMetaInfo and ExportMetaInfo are also used by export feature. See controlling export output.