Files
deb-python-pecan/pecan/jsonify.py
2012-03-11 14:51:44 -07:00

96 lines
2.4 KiB
Python

try:
from simplejson import JSONEncoder
except ImportError: # pragma: no cover
from json import JSONEncoder # noqa
from datetime import datetime, date
from decimal import Decimal
# depending on the version WebOb might have 2 types of dicts
try:
# WebOb <= 1.1.1
from webob.multidict import MultiDict, UnicodeMultiDict
webob_dicts = (MultiDict, UnicodeMultiDict) # pragma: no cover
except ImportError: # pragma no cover
# WebOb >= 1.2
from webob.multidict import MultiDict
webob_dicts = (MultiDict,)
from simplegeneric import generic
try:
from sqlalchemy.engine.base import ResultProxy, RowProxy
except ImportError: # pragma no cover
# dummy classes since we don't have SQLAlchemy installed
class ResultProxy:
pass
class RowProxy:
pass
#
# exceptions
#
class JsonEncodeError(Exception):
pass
#
# encoders
#
def is_saobject(obj):
return hasattr(obj, '_sa_class_manager')
class GenericJSON(JSONEncoder):
def default(self, obj):
if hasattr(obj, '__json__') and callable(obj.__json__):
return obj.__json__()
elif isinstance(obj, (date, datetime)):
return str(obj)
elif isinstance(obj, Decimal):
# XXX What to do about JSONEncoder crappy handling of Decimals?
# SimpleJSON has better Decimal encoding than the std lib
# but only in recent versions
return float(obj)
elif is_saobject(obj):
props = {}
for key in obj.__dict__:
if not key.startswith('_sa_'):
props[key] = getattr(obj, key)
return props
elif isinstance(obj, ResultProxy):
props = dict(rows=list(obj), count=obj.rowcount)
if props['count'] < 0:
props['count'] = len(props['rows'])
return props
elif isinstance(obj, RowProxy):
return dict(obj)
elif isinstance(obj, webob_dicts):
return obj.mixed()
else:
return JSONEncoder.default(self, obj)
_default = GenericJSON()
@generic
def jsonify(obj):
return _default.default(obj)
class GenericFunctionJSON(GenericJSON):
def default(self, obj):
return jsonify(obj)
_instance = GenericFunctionJSON()
def encode(obj):
return _instance.encode(obj)