Storing versions of objects in object stores

You use the methods described in this section to share objects between every edition of an application.

Each application and subapplication in a library has a common object store in which you can deposit named versions of objects. Because these objects have edition time stamps, you can retrieve a specific edition at any time. In order to use these features, load the configuration map LibraryObjectStorage into your image.

Unlike user fields, every new edition of a specific named object is accessible to every edition of an application. References to inherited user fields are copied when new editions are created; thus, any change to a field from a previous edition of a component is not visible to any other edition of the component.

The methods (implemented in SubApplication) you use include the following:

allObjectNames

Answers all the names of objects in the receiver's object store.

atObjectNamed: aName put: anObject

Stores anObject in the receiver's object store using the key aName. Answers the timeStamp for the new edition.

latestObjectNamed: aName

Answers the latest edition of the object with the given name.

objectNamed: aName at: aTimeStamp

Answers the edition of the object named aName whose timestamp is aTimeStamp. Answers nil if it is missing.

objectNamed: aName at: aTimeStamp ifAbsent: aBlock

Answers the edition of the object named aName whose timestamp is aTimeStamp. If the object was not found, answers the result of evaluating aBlock.