Source code for fedmsg.encoding.sqla

# This file is part of fedmsg.
# Copyright (C) 2012 Red Hat, Inc.
# fedmsg is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# fedmsg is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public
# License along with fedmsg; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
# Authors:  Ralph Bean <>
""" :mod:`fedmsg.encoding.sqla` houses utility functions for JSONifying
sqlalchemy models that do not define their own ``.__json__()`` methods.

Use at your own risk.  :func:`fedmsg.encoding.sqla.to_json` will expose all
attributes and relations of your sqlalchemy object and may expose information
you not want it to.  See :ref:`api-crypto` for considerations.

    from sqlalchemy.orm import class_mapper
    from import RelationshipProperty
except ImportError:

[docs]def to_json(obj, seen=None): """ Returns a dict representation of the object. Recursively evaluates to_json(...) on its relationships. """ if not seen: seen = [] properties = list(class_mapper(type(obj)).iterate_properties) relationships = [ p.key for p in properties if type(p) is RelationshipProperty ] attrs = [ p.key for p in properties if p.key not in relationships ] d = dict([(attr, getattr(obj, attr)) for attr in attrs]) for attr in relationships: d[attr] = expand(obj, getattr(obj, attr), seen) return d
[docs]def expand(obj, relation, seen): """ Return the to_json or id of a sqlalchemy relationship. """ if hasattr(relation, 'all'): relation = relation.all() if hasattr(relation, '__iter__'): return [expand(obj, item, seen) for item in relation] if type(relation) not in seen: return to_json(relation, seen + [type(obj)]) else: return