[Followup-To zodb-dev] Dennis Allison wrote:
I am having trouble understanding what they are and how one gets from a "state" to the ZODB value associated with thast state. Can someone assist?
The state is whatever __getstate__ and __getstate__ manipulate. It has to be picklable. For persistent classes, an instance dict is the common case. persistent.Persistent.__getstate__ has this docstring: """ Get the object serialization state If the object has no assigned slots and has no instance dictionary, then None is returned. If the object has no assigned slots and has an instance dictionary, then the a copy of the instance dictionary is returned. The copy has any items with names starting with '_v_' or '_p_' ommitted. If the object has assigned slots, then a two-element tuple is returned. The first element is either None or a copy of the instance dictionary, as described above. The second element is a dictionary with items for each of the assigned slots. """ Other classes can specialise the methods, see for instance BTrees.Length. Florent -- Florent Guillaume, Nuxeo (Paris, France) Director of R&D +33 1 40 33 71 59 http://nuxeo.com fg@nuxeo.com