gramps/gramps/gen/lib/refbase.py
2013-12-24 09:28:37 -05:00

108 lines
3.3 KiB
Python

#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2006 Donald N. Allingham
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# $Id$
"""
Base Reference class for Gramps.
"""
from .handle import Handle
#-------------------------------------------------------------------------
#
# RefBase class
#
#-------------------------------------------------------------------------
class RefBase(object):
"""
Base reference class to manage references to other objects.
Any *Ref* classes should derive from this class.
"""
def __init__(self, source=None):
if source:
self.ref = source.ref
else:
self.ref = None
def serialize(self):
"""
Convert the object to a serialized tuple of data.
"""
return self.ref
def to_struct(self):
"""
Convert the data held in this object to a structure (eg,
struct) that represents all the data elements.
This method is used to recursively convert the object into a
self-documenting form that can easily be used for various
purposes, including diffs and queries.
These structures may be primitive Python types (string,
integer, boolean, etc.) or complex Python types (lists,
tuples, or dicts). If the return type is a dict, then the keys
of the dict match the fieldname of the object. If the return
struct (or value of a dict key) is a list, then it is a list
of structs. Otherwise, the struct is just the value of the
attribute.
:returns: Returns a struct containing the data of the object.
:rtype: str
"""
## Return name of referenced item (remove "Ref" from name)
return Handle(self.__class__.__name__[:-3], self.ref)
@classmethod
def from_struct(cls, struct):
"""
Given a struct data representation, return a serialized object.
:returns: Returns a serialized object
"""
return struct
def unserialize(self, data):
"""
Convert a serialized tuple of data to an object.
"""
self.ref = str(data)
return self
def get_referenced_handles(self):
"""
Returns the list of (classname, handle) tuples for all directly
referenced primary objects.
:returns: Returns the list of (classname, handle) tuples for referenced
objects.
:rtype: list
"""
assert False, "Must be overridden in the derived class"
def set_reference_handle(self, val):
self.ref = val
def get_reference_handle(self):
return self.ref