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document.py
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document.py
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import copy
import operator
import numbers
from functools import partial
import pymongo
from bson import json_util
from bson.dbref import DBRef
from mongoengine import signals
from mongoengine.common import _import_class
from mongoengine.errors import (ValidationError, InvalidDocumentError,
LookUpError)
from mongoengine.python_support import (PY3, UNICODE_KWARGS, txt_type,
to_str_keys_recursive)
from mongoengine.base.common import get_document, ALLOW_INHERITANCE
from mongoengine.base.datastructures import BaseDict, BaseList
from mongoengine.base.fields import ComplexBaseField
__all__ = ('BaseDocument', 'NON_FIELD_ERRORS')
NON_FIELD_ERRORS = '__all__'
class BaseDocument(object):
_dynamic = False
_created = True
_dynamic_lock = True
_initialised = False
def __init__(self, *args, **values):
"""
Initialise a document or embedded document
:param __auto_convert: Try and will cast python objects to Object types
:param values: A dictionary of values for the document
"""
if args:
# Combine positional arguments with named arguments.
# We only want named arguments.
field = iter(self._fields_ordered)
for value in args:
name = next(field)
if name in values:
raise TypeError("Multiple values for keyword argument '" + name + "'")
values[name] = value
__auto_convert = values.pop("__auto_convert", True)
signals.pre_init.send(self.__class__, document=self, values=values)
self._data = {}
# Assign default values to instance
for key, field in self._fields.iteritems():
if self._db_field_map.get(key, key) in values:
continue
value = getattr(self, key, None)
setattr(self, key, value)
# Set passed values after initialisation
if self._dynamic:
self._dynamic_fields = {}
dynamic_data = {}
for key, value in values.iteritems():
if key in self._fields or key == '_id':
setattr(self, key, value)
elif self._dynamic:
dynamic_data[key] = value
else:
FileField = _import_class('FileField')
for key, value in values.iteritems():
if key == '__auto_convert':
continue
key = self._reverse_db_field_map.get(key, key)
if key in self._fields or key in ('id', 'pk', '_cls'):
if __auto_convert and value is not None:
field = self._fields.get(key)
if field and not isinstance(field, FileField):
value = field.to_python(value)
setattr(self, key, value)
else:
self._data[key] = value
# Set any get_fieldname_display methods
self.__set_field_display()
if self._dynamic:
self._dynamic_lock = False
for key, value in dynamic_data.iteritems():
setattr(self, key, value)
# Flag initialised
self._initialised = True
signals.post_init.send(self.__class__, document=self)
def __delattr__(self, *args, **kwargs):
"""Handle deletions of fields"""
field_name = args[0]
if field_name in self._fields:
default = self._fields[field_name].default
if callable(default):
default = default()
setattr(self, field_name, default)
else:
super(BaseDocument, self).__delattr__(*args, **kwargs)
def __setattr__(self, name, value):
# Handle dynamic data only if an initialised dynamic document
if self._dynamic and not self._dynamic_lock:
field = None
if not hasattr(self, name) and not name.startswith('_'):
DynamicField = _import_class("DynamicField")
field = DynamicField(db_field=name)
field.name = name
self._dynamic_fields[name] = field
if not name.startswith('_'):
value = self.__expand_dynamic_values(name, value)
# Handle marking data as changed
if name in self._dynamic_fields:
self._data[name] = value
if hasattr(self, '_changed_fields'):
self._mark_as_changed(name)
if (self._is_document and not self._created and
name in self._meta.get('shard_key', tuple()) and
self._data.get(name) != value):
OperationError = _import_class('OperationError')
msg = "Shard Keys are immutable. Tried to update %s" % name
raise OperationError(msg)
# Check if the user has created a new instance of a class
if (self._is_document and self._initialised
and self._created and name == self._meta['id_field']):
super(BaseDocument, self).__setattr__('_created', False)
super(BaseDocument, self).__setattr__(name, value)
def __getstate__(self):
removals = ("get_%s_display" % k
for k, v in self._fields.items() if v.choices)
for k in removals:
if hasattr(self, k):
delattr(self, k)
return self.__dict__
def __setstate__(self, __dict__):
self.__dict__ = __dict__
self.__set_field_display()
def __iter__(self):
if 'id' in self._fields and 'id' not in self._fields_ordered:
return iter(('id', ) + self._fields_ordered)
return iter(self._fields_ordered)
def __getitem__(self, name):
"""Dictionary-style field access, return a field's value if present.
"""
try:
if name in self._fields:
return getattr(self, name)
except AttributeError:
pass
raise KeyError(name)
def __setitem__(self, name, value):
"""Dictionary-style field access, set a field's value.
"""
# Ensure that the field exists before settings its value
if name not in self._fields:
raise KeyError(name)
return setattr(self, name, value)
def __contains__(self, name):
try:
val = getattr(self, name)
return val is not None
except AttributeError:
return False
def __len__(self):
return len(self._data)
def __repr__(self):
try:
u = self.__str__()
except (UnicodeEncodeError, UnicodeDecodeError):
u = '[Bad Unicode data]'
repr_type = type(u)
return repr_type('<%s: %s>' % (self.__class__.__name__, u))
def __str__(self):
if hasattr(self, '__unicode__'):
if PY3:
return self.__unicode__()
else:
return unicode(self).encode('utf-8')
return txt_type('%s object' % self.__class__.__name__)
def __eq__(self, other):
if isinstance(other, self.__class__) and hasattr(other, 'id'):
if self.id == other.id:
return True
return False
def __ne__(self, other):
return not self.__eq__(other)
def __hash__(self):
if self.pk is None:
# For new object
return super(BaseDocument, self).__hash__()
else:
return hash(self.pk)
def clean(self):
"""
Hook for doing document level data cleaning before validation is run.
Any ValidationError raised by this method will not be associated with
a particular field; it will have a special-case association with the
field defined by NON_FIELD_ERRORS.
"""
pass
def to_mongo(self):
"""Return data dictionary ready for use with MongoDB.
"""
data = {}
for field_name, field in self._fields.iteritems():
value = self._data.get(field_name, None)
if value is not None:
value = field.to_mongo(value)
# Handle self generating fields
if value is None and field._auto_gen:
value = field.generate()
self._data[field_name] = value
if value is not None:
data[field.db_field] = value
# Only add _cls if allow_inheritance is True
if (hasattr(self, '_meta') and
self._meta.get('allow_inheritance', ALLOW_INHERITANCE) == True):
data['_cls'] = self._class_name
if '_id' in data and data['_id'] is None:
del data['_id']
if not self._dynamic:
return data
for name, field in self._dynamic_fields.items():
data[name] = field.to_mongo(self._data.get(name, None))
return data
def validate(self, clean=True):
"""Ensure that all fields' values are valid and that required fields
are present.
"""
# Ensure that each field is matched to a valid value
errors = {}
if clean:
try:
self.clean()
except ValidationError, error:
errors[NON_FIELD_ERRORS] = error
# Get a list of tuples of field names and their current values
fields = [(field, self._data.get(name))
for name, field in self._fields.items()]
if self._dynamic:
fields += [(field, self._data.get(name))
for name, field in self._dynamic_fields.items()]
EmbeddedDocumentField = _import_class("EmbeddedDocumentField")
GenericEmbeddedDocumentField = _import_class("GenericEmbeddedDocumentField")
for field, value in fields:
if value is not None:
try:
if isinstance(field, (EmbeddedDocumentField,
GenericEmbeddedDocumentField)):
field._validate(value, clean=clean)
else:
field._validate(value)
except ValidationError, error:
errors[field.name] = error.errors or error
except (ValueError, AttributeError, AssertionError), error:
errors[field.name] = error
elif field.required and not getattr(field, '_auto_gen', False):
errors[field.name] = ValidationError('Field is required',
field_name=field.name)
if errors:
pk = "None"
if hasattr(self, 'pk'):
pk = self.pk
elif self._instance:
pk = self._instance.pk
message = "ValidationError (%s:%s) " % (self._class_name, pk)
raise ValidationError(message, errors=errors)
def to_json(self):
"""Converts a document to JSON"""
return json_util.dumps(self.to_mongo())
@classmethod
def from_json(cls, json_data):
"""Converts json data to an unsaved document instance"""
return cls._from_son(json_util.loads(json_data))
def __expand_dynamic_values(self, name, value):
"""expand any dynamic values to their correct types / values"""
if not isinstance(value, (dict, list, tuple)):
return value
is_list = False
if not hasattr(value, 'items'):
is_list = True
value = dict([(k, v) for k, v in enumerate(value)])
if not is_list and '_cls' in value:
cls = get_document(value['_cls'])
return cls(**value)
data = {}
for k, v in value.items():
key = name if is_list else k
data[k] = self.__expand_dynamic_values(key, v)
if is_list: # Convert back to a list
data_items = sorted(data.items(), key=operator.itemgetter(0))
value = [v for k, v in data_items]
else:
value = data
# Convert lists / values so we can watch for any changes on them
if (isinstance(value, (list, tuple)) and
not isinstance(value, BaseList)):
value = BaseList(value, self, name)
elif isinstance(value, dict) and not isinstance(value, BaseDict):
value = BaseDict(value, self, name)
return value
def _mark_as_changed(self, key):
"""Marks a key as explicitly changed by the user
"""
if not key:
return
key = self._db_field_map.get(key, key)
if (hasattr(self, '_changed_fields') and
key not in self._changed_fields):
self._changed_fields.append(key)
def _clear_changed_fields(self):
self._changed_fields = []
EmbeddedDocumentField = _import_class("EmbeddedDocumentField")
for field_name, field in self._fields.iteritems():
if (isinstance(field, ComplexBaseField) and
isinstance(field.field, EmbeddedDocumentField)):
field_value = getattr(self, field_name, None)
if field_value:
for idx in (field_value if isinstance(field_value, dict)
else xrange(len(field_value))):
field_value[idx]._clear_changed_fields()
elif isinstance(field, EmbeddedDocumentField):
field_value = getattr(self, field_name, None)
if field_value:
field_value._clear_changed_fields()
def _get_changed_fields(self, key='', inspected=None):
"""Returns a list of all fields that have explicitly been changed.
"""
EmbeddedDocument = _import_class("EmbeddedDocument")
DynamicEmbeddedDocument = _import_class("DynamicEmbeddedDocument")
_changed_fields = []
_changed_fields += getattr(self, '_changed_fields', [])
inspected = inspected or set()
if hasattr(self, 'id'):
if self.id in inspected:
return _changed_fields
inspected.add(self.id)
field_list = self._fields.copy()
if self._dynamic:
field_list.update(self._dynamic_fields)
for field_name in field_list:
db_field_name = self._db_field_map.get(field_name, field_name)
key = '%s.' % db_field_name
field = self._data.get(field_name, None)
if hasattr(field, 'id'):
if field.id in inspected:
continue
inspected.add(field.id)
if (isinstance(field, (EmbeddedDocument, DynamicEmbeddedDocument))
and db_field_name not in _changed_fields):
# Find all embedded fields that have been changed
changed = field._get_changed_fields(key, inspected)
_changed_fields += ["%s%s" % (key, k) for k in changed if k]
elif (isinstance(field, (list, tuple, dict)) and
db_field_name not in _changed_fields):
# Loop list / dict fields as they contain documents
# Determine the iterator to use
if not hasattr(field, 'items'):
iterator = enumerate(field)
else:
iterator = field.iteritems()
for index, value in iterator:
if not hasattr(value, '_get_changed_fields'):
continue
list_key = "%s%s." % (key, index)
changed = value._get_changed_fields(list_key, inspected)
_changed_fields += ["%s%s" % (list_key, k)
for k in changed if k]
return _changed_fields
def _delta(self):
"""Returns the delta (set, unset) of the changes for a document.
Gets any values that have been explicitly changed.
"""
# Handles cases where not loaded from_son but has _id
doc = self.to_mongo()
set_fields = self._get_changed_fields()
set_data = {}
unset_data = {}
parts = []
if hasattr(self, '_changed_fields'):
set_data = {}
# Fetch each set item from its path
for path in set_fields:
parts = path.split('.')
d = doc
new_path = []
for p in parts:
if isinstance(d, DBRef):
break
elif isinstance(d, list) and p.isdigit():
d = d[int(p)]
elif hasattr(d, 'get'):
d = d.get(p)
new_path.append(p)
path = '.'.join(new_path)
set_data[path] = d
else:
set_data = doc
if '_id' in set_data:
del(set_data['_id'])
# Determine if any changed items were actually unset.
for path, value in set_data.items():
if value or isinstance(value, (numbers.Number, bool)):
continue
# If we've set a value that ain't the default value dont unset it.
default = None
if (self._dynamic and len(parts) and parts[0] in
self._dynamic_fields):
del(set_data[path])
unset_data[path] = 1
continue
elif path in self._fields:
default = self._fields[path].default
else: # Perform a full lookup for lists / embedded lookups
d = self
parts = path.split('.')
db_field_name = parts.pop()
for p in parts:
if isinstance(d, list) and p.isdigit():
d = d[int(p)]
elif (hasattr(d, '__getattribute__') and
not isinstance(d, dict)):
real_path = d._reverse_db_field_map.get(p, p)
d = getattr(d, real_path)
else:
d = d.get(p)
if hasattr(d, '_fields'):
field_name = d._reverse_db_field_map.get(db_field_name,
db_field_name)
if field_name in d._fields:
default = d._fields.get(field_name).default
else:
default = None
if default is not None:
if callable(default):
default = default()
if default != value:
continue
del(set_data[path])
unset_data[path] = 1
return set_data, unset_data
@classmethod
def _get_collection_name(cls):
"""Returns the collection name for this class.
"""
return cls._meta.get('collection', None)
@classmethod
def _from_son(cls, son, _auto_dereference=True):
"""Create an instance of a Document (subclass) from a PyMongo SON.
"""
# get the class name from the document, falling back to the given
# class if unavailable
class_name = son.get('_cls', cls._class_name)
data = dict(("%s" % key, value) for key, value in son.iteritems())
if not UNICODE_KWARGS:
# python 2.6.4 and lower cannot handle unicode keys
# passed to class constructor example: cls(**data)
to_str_keys_recursive(data)
# Return correct subclass for document type
if class_name != cls._class_name:
cls = get_document(class_name)
changed_fields = []
errors_dict = {}
fields = cls._fields
if not _auto_dereference:
fields = copy.copy(fields)
for field_name, field in fields.iteritems():
field._auto_dereference = _auto_dereference
if field.db_field in data:
value = data[field.db_field]
try:
data[field_name] = (value if value is None
else field.to_python(value))
if field_name != field.db_field:
del data[field.db_field]
except (AttributeError, ValueError), e:
errors_dict[field_name] = e
elif field.default:
default = field.default
if callable(default):
default = default()
if isinstance(default, BaseDocument):
changed_fields.append(field_name)
if errors_dict:
errors = "\n".join(["%s - %s" % (k, v)
for k, v in errors_dict.items()])
msg = ("Invalid data to create a `%s` instance.\n%s"
% (cls._class_name, errors))
raise InvalidDocumentError(msg)
obj = cls(__auto_convert=False, **data)
obj._changed_fields = changed_fields
obj._created = False
if not _auto_dereference:
obj._fields = fields
return obj
@classmethod
def _build_index_specs(cls, meta_indexes):
"""Generate and merge the full index specs
"""
geo_indices = cls._geo_indices()
unique_indices = cls._unique_with_indexes()
index_specs = [cls._build_index_spec(spec)
for spec in meta_indexes]
def merge_index_specs(index_specs, indices):
if not indices:
return index_specs
spec_fields = [v['fields']
for k, v in enumerate(index_specs)]
# Merge unqiue_indexes with existing specs
for k, v in enumerate(indices):
if v['fields'] in spec_fields:
index_specs[spec_fields.index(v['fields'])].update(v)
else:
index_specs.append(v)
return index_specs
index_specs = merge_index_specs(index_specs, geo_indices)
index_specs = merge_index_specs(index_specs, unique_indices)
return index_specs
@classmethod
def _build_index_spec(cls, spec):
"""Build a PyMongo index spec from a MongoEngine index spec.
"""
if isinstance(spec, basestring):
spec = {'fields': [spec]}
elif isinstance(spec, (list, tuple)):
spec = {'fields': list(spec)}
elif isinstance(spec, dict):
spec = dict(spec)
index_list = []
direction = None
# Check to see if we need to include _cls
allow_inheritance = cls._meta.get('allow_inheritance',
ALLOW_INHERITANCE)
include_cls = allow_inheritance and not spec.get('sparse', False)
for key in spec['fields']:
# If inherited spec continue
if isinstance(key, (list, tuple)):
continue
# ASCENDING from +,
# DESCENDING from -
# GEO2D from *
direction = pymongo.ASCENDING
if key.startswith("-"):
direction = pymongo.DESCENDING
elif key.startswith("*"):
direction = pymongo.GEO2D
if key.startswith(("+", "-", "*")):
key = key[1:]
# Use real field name, do it manually because we need field
# objects for the next part (list field checking)
parts = key.split('.')
if parts in (['pk'], ['id'], ['_id']):
key = '_id'
fields = []
else:
fields = cls._lookup_field(parts)
parts = [field if field == '_id' else field.db_field
for field in fields]
key = '.'.join(parts)
index_list.append((key, direction))
# Don't add cls to a geo index
if include_cls and direction is not pymongo.GEO2D:
index_list.insert(0, ('_cls', 1))
spec['fields'] = index_list
if spec.get('sparse', False) and len(spec['fields']) > 1:
raise ValueError(
'Sparse indexes can only have one field in them. '
'See https://jira.mongodb.org/browse/SERVER-2193')
return spec
@classmethod
def _unique_with_indexes(cls, namespace=""):
"""
Find and set unique indexes
"""
unique_indexes = []
for field_name, field in cls._fields.items():
sparse = False
# Generate a list of indexes needed by uniqueness constraints
if field.unique:
field.required = True
unique_fields = [field.db_field]
# Add any unique_with fields to the back of the index spec
if field.unique_with:
if isinstance(field.unique_with, basestring):
field.unique_with = [field.unique_with]
# Convert unique_with field names to real field names
unique_with = []
for other_name in field.unique_with:
parts = other_name.split('.')
# Lookup real name
parts = cls._lookup_field(parts)
name_parts = [part.db_field for part in parts]
unique_with.append('.'.join(name_parts))
# Unique field should be required
parts[-1].required = True
sparse = (not sparse and
parts[-1].name not in cls.__dict__)
unique_fields += unique_with
# Add the new index to the list
fields = [("%s%s" % (namespace, f), pymongo.ASCENDING)
for f in unique_fields]
index = {'fields': fields, 'unique': True, 'sparse': sparse}
unique_indexes.append(index)
# Grab any embedded document field unique indexes
if (field.__class__.__name__ == "EmbeddedDocumentField" and
field.document_type != cls):
field_namespace = "%s." % field_name
doc_cls = field.document_type
unique_indexes += doc_cls._unique_with_indexes(field_namespace)
return unique_indexes
@classmethod
def _geo_indices(cls, inspected=None):
inspected = inspected or []
geo_indices = []
inspected.append(cls)
EmbeddedDocumentField = _import_class("EmbeddedDocumentField")
GeoPointField = _import_class("GeoPointField")
for field in cls._fields.values():
if not isinstance(field, (EmbeddedDocumentField, GeoPointField)):
continue
if hasattr(field, 'document_type'):
field_cls = field.document_type
if field_cls in inspected:
continue
if hasattr(field_cls, '_geo_indices'):
geo_indices += field_cls._geo_indices(inspected)
elif field._geo_index:
geo_indices.append({'fields':
[(field.db_field, pymongo.GEO2D)]})
return geo_indices
@classmethod
def _lookup_field(cls, parts):
"""Lookup a field based on its attribute and return a list containing
the field's parents and the field.
"""
if not isinstance(parts, (list, tuple)):
parts = [parts]
fields = []
field = None
for field_name in parts:
# Handle ListField indexing:
if field_name.isdigit():
new_field = field.field
fields.append(field_name)
continue
if field is None:
# Look up first field from the document
if field_name == 'pk':
# Deal with "primary key" alias
field_name = cls._meta['id_field']
if field_name in cls._fields:
field = cls._fields[field_name]
elif cls._dynamic:
DynamicField = _import_class('DynamicField')
field = DynamicField(db_field=field_name)
else:
raise LookUpError('Cannot resolve field "%s"'
% field_name)
else:
ReferenceField = _import_class('ReferenceField')
GenericReferenceField = _import_class('GenericReferenceField')
if isinstance(field, (ReferenceField, GenericReferenceField)):
raise LookUpError('Cannot perform join in mongoDB: %s' %
'__'.join(parts))
if hasattr(getattr(field, 'field', None), 'lookup_member'):
new_field = field.field.lookup_member(field_name)
else:
# Look up subfield on the previous field
new_field = field.lookup_member(field_name)
if not new_field and isinstance(field, ComplexBaseField):
fields.append(field_name)
continue
elif not new_field:
raise LookUpError('Cannot resolve field "%s"'
% field_name)
field = new_field # update field to the new field type
fields.append(field)
return fields
@classmethod
def _translate_field_name(cls, field, sep='.'):
"""Translate a field attribute name to a database field name.
"""
parts = field.split(sep)
parts = [f.db_field for f in cls._lookup_field(parts)]
return '.'.join(parts)
def __set_field_display(self):
"""Dynamically set the display value for a field with choices"""
for attr_name, field in self._fields.items():
if field.choices:
setattr(self,
'get_%s_display' % attr_name,
partial(self.__get_field_display, field=field))
def __get_field_display(self, field):
"""Returns the display value for a choice field"""
value = getattr(self, field.name)
if field.choices and isinstance(field.choices[0], (list, tuple)):
return dict(field.choices).get(value, value)
return value