The initial implementation of the new ChangeApplier (for the
FLUID-5115 model relay system) currently ignores any "priority" field attached to a listener. It wasn't initially clear what the semantic of this field should be given the lack of one-to-one correspondence in the new system between changes and firings, but work on the metadata component revealed at least one clear use case - model listeners added as instrumentation by the IoC testing framework, for example, should definitely be notified after all listeners forming the implementation, otherwise they will see an incompletely updated condition of the model and view state.
This was raised in IRC on 5/5/14 -
The code at this link https://github.com/cindyli/metadata/blob/FLOE-171/tests/js/resourceInputPanelTestUtils.js#L94 reads
despite the attempt to push the listener to the last place, it ends up being notified before the "updateModel" listener in the implementation.