Object operations

These are performed on each object instance as a whole. Object operations:

• do not operate on individual attributes. All attributes on the command line must be handled atomically to the calling of the operation.

• must be written to change the object instance successfully without error or, if that is not possible, to make no changes.

• must be written to process one object instance at a time.

create

Create the object; assign any attributes to the object instance.

delete

Remove the object instance.

action

Perform this action with arguments specified. The Server API will not check the arguments or any returned information for validity.

list

Evaluates the given object instance and returns a list of all the object instances that are contained by the specified object instance. This is used in containment and scoping. Every class that has object instances contained by another should have a list function.

Those procedures that are invoked per object will be called only once per object instance listed in a client's request.

In the passed data structure, only these parameters are important to per-object operations:

class name

The class to which the specified object instance belongs. This accommodates sharing procedures between classes.

object name

The object instance being worked on. The OSA should check the existence or validity of the object instance.

template object name

The name of a template object instance used by the create operation to create the specified object instance. When used, the template is created by duplicating an existing object instance. If a template is not used, the field is blank.

operation name

The operation being worked on. This accommodates procedures being shared by operations by providing a way for the procedure to identify which operation is calling it.

attribute token

The token for the attribute being worked on. Simple operations can act on each attribute in one procedure, but more complex operations can simply identify which attribute is being worked on and forward the relevant information to an appropriate subroutine.

attribute list

The attributes (and corresponding values) specified when the operation was called.