2010-02-15 14:25:49 -08:00

340 lines
11 KiB
Python

from base import BaseField, ObjectIdField, ValidationError
from document import Document, EmbeddedDocument
from connection import _get_db
import re
import pymongo
import datetime
import decimal
__all__ = ['StringField', 'IntField', 'FloatField', 'BooleanField',
'DateTimeField', 'EmbeddedDocumentField', 'ListField', 'DictField',
'ObjectIdField', 'ReferenceField', 'ValidationError',
'DecimalField', 'URLField']
class StringField(BaseField):
"""A unicode string field.
"""
def __init__(self, regex=None, max_length=None, **kwargs):
self.regex = re.compile(regex) if regex else None
self.max_length = max_length
super(StringField, self).__init__(**kwargs)
def to_python(self, value):
return unicode(value)
def validate(self, value):
assert isinstance(value, (str, unicode))
if self.max_length is not None and len(value) > self.max_length:
raise ValidationError('String value is too long')
if self.regex is not None and self.regex.match(value) is None:
message = 'String value did not match validation regex'
raise ValidationError(message)
def lookup_member(self, member_name):
return None
class URLField(BaseField):
"""A field that validates input as a URL.
"""
def __init__(self, verify_exists=True, **kwargs):
self.verify_exists = verify_exists
super(URLField, self).__init__(**kwargs)
def validate(self, value):
import urllib2
if self.verify_exists:
try:
request = urllib2.Request(value)
response = urllib2.urlopen(request)
except Exception, e:
raise ValidationError('This URL appears to be invalid: %s' % e)
class IntField(BaseField):
"""An integer field.
"""
def __init__(self, min_value=None, max_value=None, **kwargs):
self.min_value, self.max_value = min_value, max_value
super(IntField, self).__init__(**kwargs)
def to_python(self, value):
return int(value)
def validate(self, value):
try:
value = int(value)
except:
raise ValidationError('%s could not be converted to int' % value)
if self.min_value is not None and value < self.min_value:
raise ValidationError('Integer value is too small')
if self.max_value is not None and value > self.max_value:
raise ValidationError('Integer value is too large')
class FloatField(BaseField):
"""An floating point number field.
"""
def __init__(self, min_value=None, max_value=None, **kwargs):
self.min_value, self.max_value = min_value, max_value
super(FloatField, self).__init__(**kwargs)
def to_python(self, value):
return float(value)
def validate(self, value):
if isinstance(value, int):
value = float(value)
assert isinstance(value, float)
if self.min_value is not None and value < self.min_value:
raise ValidationError('Float value is too small')
if self.max_value is not None and value > self.max_value:
raise ValidationError('Float value is too large')
class DecimalField(BaseField):
"""A fixed-point decimal number field.
"""
def __init__(self, min_value=None, max_value=None, **kwargs):
self.min_value, self.max_value = min_value, max_value
super(DecimalField, self).__init__(**kwargs)
def to_python(self, value):
if not isinstance(value, basestring):
value = unicode(value)
return decimal.Decimal(value)
def validate(self, value):
if not isinstance(value, decimal.Decimal):
if not isinstance(value, basestring):
value = str(value)
try:
value = decimal.Decimal(value)
except Exception, exc:
raise ValidationError('Could not convert to decimal: %s' % exc)
if self.min_value is not None and value < self.min_value:
raise ValidationError('Decimal value is too small')
if self.max_value is not None and vale > self.max_value:
raise ValidationError('Decimal value is too large')
class BooleanField(BaseField):
"""A boolean field type.
.. versionadded:: 0.1.2
"""
def to_python(self, value):
return bool(value)
def validate(self, value):
assert isinstance(value, bool)
class DateTimeField(BaseField):
"""A datetime field.
"""
def validate(self, value):
assert isinstance(value, datetime.datetime)
class EmbeddedDocumentField(BaseField):
"""An embedded document field. Only valid values are subclasses of
:class:`~mongoengine.EmbeddedDocument`.
"""
def __init__(self, document, **kwargs):
if not issubclass(document, EmbeddedDocument):
raise ValidationError('Invalid embedded document class provided '
'to an EmbeddedDocumentField')
self.document = document
super(EmbeddedDocumentField, self).__init__(**kwargs)
def to_python(self, value):
if not isinstance(value, self.document):
return self.document._from_son(value)
return value
def to_mongo(self, value):
return self.document.to_mongo(value)
def validate(self, value):
"""Make sure that the document instance is an instance of the
EmbeddedDocument subclass provided when the document was defined.
"""
# Using isinstance also works for subclasses of self.document
if not isinstance(value, self.document):
raise ValidationError('Invalid embedded document instance '
'provided to an EmbeddedDocumentField')
self.document.validate(value)
def lookup_member(self, member_name):
return self.document._fields.get(member_name)
def prepare_query_value(self, op, value):
return self.to_mongo(value)
class ListField(BaseField):
"""A list field that wraps a standard field, allowing multiple instances
of the field to be used as a list in the database.
"""
# ListFields cannot be indexed with _types - MongoDB doesn't support this
_index_with_types = False
def __init__(self, field, **kwargs):
if not isinstance(field, BaseField):
raise ValidationError('Argument to ListField constructor must be '
'a valid field')
self.field = field
super(ListField, self).__init__(**kwargs)
def __get__(self, instance, owner):
"""Descriptor to automatically dereference references.
"""
if instance is None:
# Document class being used rather than a document object
return self
if isinstance(self.field, ReferenceField):
referenced_type = self.field.document_type
# Get value from document instance if available
value_list = instance._data.get(self.name)
if value_list:
deref_list = []
for value in value_list:
# Dereference DBRefs
if isinstance(value, (pymongo.dbref.DBRef)):
value = _get_db().dereference(value)
deref_list.append(referenced_type._from_son(value))
else:
deref_list.append(value)
instance._data[self.name] = deref_list
return super(ListField, self).__get__(instance, owner)
def to_python(self, value):
return [self.field.to_python(item) for item in value]
def to_mongo(self, value):
return [self.field.to_mongo(item) for item in value]
def validate(self, value):
"""Make sure that a list of valid fields is being used.
"""
if not isinstance(value, (list, tuple)):
raise ValidationError('Only lists and tuples may be used in a '
'list field')
try:
[self.field.validate(item) for item in value]
except:
raise ValidationError('All items in a list field must be of the '
'specified type')
def prepare_query_value(self, op, value):
if op in ('set', 'unset'):
return [self.field.to_mongo(v) for v in value]
return self.field.to_mongo(value)
def lookup_member(self, member_name):
return self.field.lookup_member(member_name)
class DictField(BaseField):
"""A dictionary field that wraps a standard Python dictionary. This is
similar to an embedded document, but the structure is not defined.
.. versionadded:: 0.2.3
"""
def validate(self, value):
"""Make sure that a list of valid fields is being used.
"""
if not isinstance(value, dict):
raise ValidationError('Only dictionaries may be used in a '
'DictField')
if any(('.' in k or '$' in k) for k in value):
raise ValidationError('Invalid dictionary key name - keys may not '
'contain "." or "$" characters')
def lookup_member(self, member_name):
return BaseField(name=member_name)
class ReferenceField(BaseField):
"""A reference to a document that will be automatically dereferenced on
access (lazily).
"""
def __init__(self, document_type, **kwargs):
if not issubclass(document_type, Document):
raise ValidationError('Argument to ReferenceField constructor '
'must be a top level document class')
self.document_type = document_type
self.document_obj = None
super(ReferenceField, self).__init__(**kwargs)
def __get__(self, instance, owner):
"""Descriptor to allow lazy dereferencing.
"""
if instance is None:
# Document class being used rather than a document object
return self
# Get value from document instance if available
value = instance._data.get(self.name)
# Dereference DBRefs
if isinstance(value, (pymongo.dbref.DBRef)):
value = _get_db().dereference(value)
if value is not None:
instance._data[self.name] = self.document_type._from_son(value)
return super(ReferenceField, self).__get__(instance, owner)
def to_mongo(self, document):
id_field_name = self.document_type._meta['id_field']
id_field = self.document_type._fields[id_field_name]
if isinstance(document, Document):
# We need the id from the saved object to create the DBRef
id_ = document.id
if id_ is None:
raise ValidationError('You can only reference documents once '
'they have been saved to the database')
else:
id_ = document
id_ = id_field.to_mongo(id_)
collection = self.document_type._meta['collection']
return pymongo.dbref.DBRef(collection, id_)
def prepare_query_value(self, op, value):
return self.to_mongo(value)
def validate(self, value):
assert isinstance(value, (self.document_type, pymongo.dbref.DBRef))
def lookup_member(self, member_name):
return self.document_type._fields.get(member_name)