Expressions in DCWorkflow are TALES expressions. See TALES Overview for general TALES information. They are used as access guards and for the setting variable values.
[Note: I haven't figured out what all these contexts actually are and what you can use them for. Explanations are is welcome!]
Some of the contexts have slightly different meanings from what is provided for expressions in page templates:
container -- The content object's container
Several other contexts are also provided:
transition -- The transition object being executed
status -- The former status
workflow -- The workflow definition object
scripts -- The scripts in the workflow definition object
state_change objects provide the following attributes, some of which
are duplicates of the above information:
status is a mapping containing the workflow status. This
includes all the variables defined in the variable tab with "store
in state" checked.
object is the object being modified by workflow.
(Same as the
here variable above.)
workflow is the workflow definition object. (Same as the
workflow variable above.)
transition is the transition object being executed. (Same
transition variable above.)
old_state is the former state object. The name of the former state,
for example "published", is available as
that DCWorkflow defines
status as different entities;
the name of the current
state is stored in the
status. The word
clash is unfortunate; patches welcome.)
new_state is the destination state object. Use
to access the new state name.
kwargs is the keyword arguments passed to the doActionFor() method.
getHistory(), a method that returns a copy of the object's workflow
getPortal(), which returns the root of the portal.
ObjectMoved, exceptions that can be raised by
scripts to indicate to the workflow that an object has been moved or
getDateTime is a method that returns the DateTime of the transition.