def resolve_model(cls, name):
if inspect.isclass(name) and issubclass(name, cls.BaseClass):
return name
subclasses = {
ModelClass.__name__: ModelClass
for ModelClass in cls.all_models()
}
permutations = [name, camel(name), camel(name, upper_segments=0)]
for name in permutations:
if name in subclasses:
return subclasses[name]
if name.lower().endswith('s'):
singular = name.rstrip('sS')
if singular in subclasses:
return subclasses[singular]
if name.lower().endswith('ies'):
singular = name[:-3] + 'y'
if singular in subclasses:
return subclasses[singular]
for name in permutations:
if name in cls.BaseClass.metadata.tables:
return cls.BaseClass.metadata.tables[name]
raise ValueError('Unrecognized model: {}'.format(name))
def JSONColumnMixin(column_name, fields, admin_only=False):
"""
Creates a new mixin class with a JSON column named column_name.
The newly created mixin class will have a SQLAlchemy JSON Column, named
`column_name`, along with two other attributes column_name_fields and
column_name_qualified_fields which describe the fields that the JSON
Column is expected to hold.
For example::
>>> SocialMediaMixin = JSONColumnMixin('social_media', ['Twitter', 'LinkedIn'])
>>> SocialMediaMixin.social_media # doctest: +ELLIPSIS
Column('social_media', JSON(), ... server_default=DefaultClause('{}', for_update=False))
>>> SocialMediaMixin._social_media_fields
OrderedDict([('twitter', 'Twitter'), ('linked_in', 'LinkedIn')])
>>> SocialMediaMixin._social_media_qualified_fields
OrderedDict([('social_media__twitter', 'twitter'), ('social_media__linked_in', 'linked_in')])
Instances of the newly created mixin class have convenience accessors for
the attributes defined by `fields`, both directly and using their fully
qualified forms::
>>> sm = SocialMediaMixin()
>>> sm.twitter = 'https://twitter.com/MAGFest' # Get and set "twitter" directly
>>> sm.twitter
'https://twitter.com/MAGFest'
>>> sm.social_media__twitter # Get and set qualified "social_media__twitter"
'https://twitter.com/MAGFest'
>>> sm.social_media__twitter = '@MAGFest'
>>> sm.social_media__twitter
'@MAGFest'
>>> sm.social_media # Actual column updated appropriately
{'linked_in': '', 'twitter': '@MAGFest'}
Args:
column_name (str): The name of the column.
fields (list): A list of field names you expect the column to hold.
This can be:
- A single string, if you're only expecting the column to hold a
single field.
- A list of strings, which will be treated as the column labels,
and converted from CamelCase to under_score for the fields.
- A map of {string: string}, which will be treated as a mapping
of field names to field labels.
Returns:
type: A new mixin class with a JSON column named column_name.
"""
fields_name = '_{}_fields'.format(column_name)
qualified_fields_name = '_{}_qualified_fields'.format(column_name)
if isinstance(fields, Mapping):
fields = OrderedDict([(fieldify(k), v) for k, v in fields.items()])
else:
fields = OrderedDict([(fieldify(s), s) for s in listify(fields)])
qualified_fields = OrderedDict([(column_name + '__' + s, s)
for s in fields.keys()])
column = Column(column_name, JSON, default={}, server_default='{}')
attrs = {
column_name: column,
fields_name: fields,
qualified_fields_name: qualified_fields
}
_Mixin = type(camel(column_name) + 'Mixin', (object, ), attrs)
def _Mixin__init__(self, *args, **kwargs):
setattr(self, column_name, {})
for attr in getattr(self.__class__, fields_name).keys():
setattr(self, attr, kwargs.pop(attr, ''))
super(_Mixin, self).__init__(*args, **kwargs)
_Mixin.__init__ = _Mixin__init__
def _Mixin__declare_last__(cls):
setattr(getattr(cls, column_name), 'admin_only', admin_only)
column = cls.__table__.columns.get(column_name)
setattr(column, 'admin_only', admin_only)
_Mixin.__declare_last__ = classmethod(_Mixin__declare_last__)
def _Mixin__unqualify(cls, name):
if name in getattr(cls, qualified_fields_name):
return getattr(cls, qualified_fields_name)[name]
else:
return name
_Mixin.unqualify = classmethod(_Mixin__unqualify)
def _Mixin__getattr__(self, name):
name = self.unqualify(name)
if name in getattr(self.__class__, fields_name):
return getattr(self, column_name).get(name, '')
else:
return super(_Mixin, self).__getattr__(name)
_Mixin.__getattr__ = _Mixin__getattr__
def _Mixin__setattr__(self, name, value):
name = self.unqualify(name)
if name in getattr(self.__class__, fields_name):
fields = getattr(self, column_name)
if fields.get(name) != value:
fields[name] = value
super(_Mixin, self).__setattr__(column_name, dict(fields))
else:
super(_Mixin, self).__setattr__(name, value)
_Mixin.__setattr__ = _Mixin__setattr__
return _Mixin
def JSONColumnMixin(column_name, fields, admin_only=False):
"""
Creates a new mixin class with a JSON column named column_name.
The newly created mixin class will have a SQLAlchemy JSON Column, named
`column_name`, along with two other attributes column_name_fields and
column_name_qualified_fields which describe the fields that the JSON
Column is expected to hold.
For example::
>>> SocialMediaMixin = JSONColumnMixin('social_media', ['Twitter', 'LinkedIn'])
>>> SocialMediaMixin.social_media # doctest: +ELLIPSIS
Column('social_media', JSON(), ... server_default=DefaultClause('{}', for_update=False))
>>> SocialMediaMixin._social_media_fields
OrderedDict([('twitter', 'Twitter'), ('linked_in', 'LinkedIn')])
>>> SocialMediaMixin._social_media_qualified_fields
OrderedDict([('social_media__twitter', 'twitter'), ('social_media__linked_in', 'linked_in')])
Instances of the newly created mixin class have convenience accessors for
the attributes defined by `fields`, both directly and using their fully
qualified forms::
>>> sm = SocialMediaMixin()
>>> sm.twitter = 'https://twitter.com/MAGFest' # Get and set "twitter" directly
>>> sm.twitter
'https://twitter.com/MAGFest'
>>> sm.social_media__twitter # Get and set qualified "social_media__twitter"
'https://twitter.com/MAGFest'
>>> sm.social_media__twitter = '@MAGFest'
>>> sm.social_media__twitter
'@MAGFest'
>>> sm.social_media # Actual column updated appropriately
{'linked_in': '', 'twitter': '@MAGFest'}
Args:
column_name (str): The name of the column.
fields (list): A list of field names you expect the column to hold.
This can be:
- A single string, if you're only expecting the column to hold a
single field.
- A list of strings, which will be treated as the column labels,
and converted from CamelCase to under_score for the fields.
- A map of {string: string}, which will be treated as a mapping
of field names to field labels.
Returns:
type: A new mixin class with a JSON column named column_name.
"""
fields_name = '_{}_fields'.format(column_name)
qualified_fields_name = '_{}_qualified_fields'.format(column_name)
if isinstance(fields, Mapping):
fields = OrderedDict([(fieldify(k), v) for k, v in fields.items()])
else:
fields = OrderedDict([(fieldify(s), s) for s in listify(fields)])
qualified_fields = OrderedDict([(column_name + '__' + s, s) for s in fields.keys()])
column = Column(column_name, JSON, default={}, server_default='{}')
attrs = {
column_name: column,
fields_name: fields,
qualified_fields_name: qualified_fields
}
_Mixin = type(camel(column_name) + 'Mixin', (object,), attrs)
def _Mixin__init__(self, *args, **kwargs):
setattr(self, column_name, {})
for attr in getattr(self.__class__, fields_name).keys():
setattr(self, attr, kwargs.pop(attr, ''))
super(_Mixin, self).__init__(*args, **kwargs)
_Mixin.__init__ = _Mixin__init__
def _Mixin__declare_last__(cls):
setattr(getattr(cls, column_name), 'admin_only', admin_only)
column = cls.__table__.columns.get(column_name)
setattr(column, 'admin_only', admin_only)
_Mixin.__declare_last__ = classmethod(_Mixin__declare_last__)
def _Mixin__unqualify(cls, name):
if name in getattr(cls, qualified_fields_name):
return getattr(cls, qualified_fields_name)[name]
else:
return name
_Mixin.unqualify = classmethod(_Mixin__unqualify)
def _Mixin__getattr__(self, name):
name = self.unqualify(name)
if name in getattr(self.__class__, fields_name):
return getattr(self, column_name).get(name, '')
else:
return super(_Mixin, self).__getattr__(name)
_Mixin.__getattr__ = _Mixin__getattr__
def _Mixin__setattr__(self, name, value):
name = self.unqualify(name)
if name in getattr(self.__class__, fields_name):
fields = getattr(self, column_name)
if fields.get(name) != value:
fields[name] = value
super(_Mixin, self).__setattr__(column_name, dict(fields))
else:
super(_Mixin, self).__setattr__(name, value)
_Mixin.__setattr__ = _Mixin__setattr__
return _Mixin