NotificationWrapper is a "wide" read only interface
providing "unstructured" access to agent internals and paylod carried by
notifications.
The alternatives were:
1. Precompile assumptions regarding the notification stucture and its
payload in the trap factory
2. Use introspection but with a potential large execution overhead.
The use of delegated wrappers stands somewhere in the middle. Trap
factory can be extended with the definition and use of new wpappers
that will be able to cope with any kind of notfications. Run time overhead
is minimal as wrappers can be instantiated only once.
Tags used to locate attributes in the notification fixed (i.e. excluding
user defined fields) payload are defined. Implementations should not use
these tags in any of the notification payload. To avoid conflicts the
following convention is proposed: standard notification payload is qualified
by the "n:" prefix. Agent properties are qualified by the "a:" prefix. User
defined payload can be qualified with e.g. the "u:" prefix
version: $Revision: 23902 $ author: Spyros Pollatos author: Dimitris Andreadis
Defines the communication protocol between the caller and the data
source (notification). Implementations are expected to map the provided
attribute name to some aspect of the notification payload. The later is
defined by method prime.
Parameters: attrTag - the tag of the attribute the value of which is required the content attrTag maps to throws: MappingFailedException - if for any reason the requested attributecan not be found