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Source code for bulbs.property

# -*- coding: utf-8 -*-
#
#James Thornton (http://jamesthornton.com)
# BSD License (see LICENSE for details)
#
"""
Interface for interacting with a graph database through Rexster.

"""
# Python 3
import six
import sys
if sys.version > '3':
    long = int
    unicode = str

import datetime
import dateutil.parser
from numbers import Number

from . import utils
from .utils import get_logger, to_datetime, to_date

log = get_logger(__name__)


[docs]class Property(object): """ Abstract base class for database property types used in Models. :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexeded: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ def __init__(self, fget=None, name=None, default=None, \ nullable=True, unique=False, indexed=False): self.fget = fget self.name = name self.default = default self.nullable = nullable # These aren't implemented yet. # TODO: unique creates an index self.indexed = indexed self.unique = unique #self.constraint = constraint
[docs] def validate(self, key, value): """ Validates the Property value before saving it to the database. :param key: Property key. :type key: str :param value: Property value. :type value: object :rtype: None """ # Do null checks first so you can ignore None values in check_datatype() self._check_null(key, value) self._check_datatype(key, value)
def _check_null(self,key,value): # TODO: should this be checking that the value is True to catch empties? if self.nullable is False and value is None: log.error("Null Property Error: '%s' cannot be set to '%s'", key, value) raise ValueError def _check_datatype(self, key, value): if value is not None and isinstance(value, self.python_type) is False: log.error("Type Error: '%s' is set to %s with type %s, but must be a %s.", key, value, type(value), self.python_type) raise TypeError
[docs] def convert_to_db(self, type_system, key, value): """ Converts a Property value from its Python type to its database representation. :param type_system: TypeSystem object. :type type_system: TypeSystem :param key: Property key. :type key: str :param value: Property value. :type value: object :rtype: object """ value = self.to_db(type_system,value) return value
[docs] def convert_to_python(self, type_system, key, value): """ Converts a Property value from its database representation to its Python type. :param type_system: TypeSystem object. :type type_system: TypeSystem :param key: Property key. :type key: str :param value: Property value. :type value: object :rtype: object """ try: value = self.to_python(type_system, value) except Exception as e: log.exception("Property Type Mismatch: '%s' with value '%s': %s", key, value, e) value = None return value
[docs] def coerce(self, key, value): """ Coerces a Property value to its Python type. :param key: Property key. :type key: str :param value: Property value. :type value: object :rtype: object """ initial_datatype = type(value) try: value = self._coerce(value) return value except ValueError: log.exception("'%s' is not a valid value for %s, must be %s.", value, key, self.python_type) raise except AttributeError: log.exception("Can't set attribute '%s' to value '%s with type %s'", key, value, initial_datatype) raise
def _coerce(self, value): # overload coerce for special types like DateTime return self.python_type(value)
[docs]class String(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = unicode def to_db(self,type_system,value): return type_system.database.to_string(value) def to_python(self,type_system,value): return type_system.python.to_string(value) def _coerce(self, value): return utils.u(value)
[docs]class Integer(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = int def to_db(self,type_system,value): return type_system.database.to_integer(value) def to_python(self,type_system,value): return type_system.python.to_integer(value)
[docs]class Long(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = long def to_db(self,type_system,value): return type_system.database.to_long(value) def to_python(self,type_system,value): return type_system.python.to_long(value)
[docs]class Float(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = float def to_db(self,type_system,value): return type_system.database.to_float(value) def to_python(self,type_system,value): return type_system.python.to_float(value)
class Bool(Property):
    """
    :param fget: Method name that returns a calculated value. Defaults to None.
    :type fget: str

    :param name: Database property name. Defaults to the Property key.
    :type name: str

    :param default: Default property value. Defaults to None.
    :type default: str, int, long, float, bool, list, dict, or Callable

    :param nullable: If True, the Property can be null. Defaults to True.
    :type nullable: bool

    :param indexed: If True, index the Property in the DB. Defaults to False.
    :type indexed: bool

    :ivar fget: Name of the method that gets the calculated Property value.
    :ivar name: Database property name. Defaults to the Property key.
    :ivar default: Default property value. Defaults to None.
    :ivar nullable: If True, the Property can be null. Defaults to True.
    :ivar indexed: If True, index the Property in the DB. Defaults to False.

    .. note:: If no Properties have index=True, all Properties are indexed.

    """
    #: Python type
    python_type = bool

    def to_db(self,type_system,value):
        return type_system.database.to_bool(value)

    def to_python(self,type_system,value):
        return type_system.python.to_bool(value)

[docs]class Null(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = None def to_db(self,type_system,value): return type_system.database.to_null(value) def to_python(self,type_system,value): return type_system.python.to_null(value)
[docs]class List(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = list def to_db(self,type_system,value): return type_system.database.to_list(value) def to_python(self,type_system,value): return type_system.python.to_list(value)
[docs]class Dictionary(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = dict def to_db(self,type_system,value): return type_system.database.to_dictionary(value) def to_python(self,type_system,value): return type_system.python.to_dictionary(value)
class Document(Property):
    """
    :param fget: Method name that returns a calculated value. Defaults to None.
    :type fget: str
 
    :param name: Database property name. Defaults to the Property key.
    :type name: str

    :param default: Default property value. Defaults to None.
    :type default: str, int, long, float, list, dict, or Callable

    :param nullable: If True, the Property can be null. Defaults to True.
    :type nullable: bool

    :param indexed: If True, index the Property in the DB. Defaults to False.
    :type indexed: bool

    :ivar fget: Name of the method that gets the calculated Property value.
    :ivar name: Database property name. Defaults to the Property key.
    :ivar default: Default property value. Defaults to None.
    :ivar nullable: If True, the Property can be null. Defaults to True.
    :ivar indexed: If True, index the Property in the DB. Defaults to False.

    .. note:: If no Properties have index=True, all Properties are indexed. 

    """
    #: Python type
    python_type = dict

    def to_db(self,type_system,value):
        return type_system.database.to_document(value)

    def to_python(self,type_system,value):
        return type_system.python.to_dictionary(value)


[docs]class DateTime(Property): """ :param fget: Method name that returns a calculated value. Defaults to None. :type fget: str :param name: Database property name. Defaults to the Property key. :type name: str :param default: Default property value. Defaults to None. :type default: str, int, long, float, list, dict, or Callable :param nullable: If True, the Property can be null. Defaults to True. :type nullable: bool :param indexed: If True, index the Property in the DB. Defaults to False. :type indexed: bool :ivar fget: Name of the method that gets the calculated Property value. :ivar name: Database property name. Defaults to the Property key. :ivar default: Default property value. Defaults to None. :ivar nullable: If True, the Property can be null. Defaults to True. :ivar indexed: If True, index the Property in the DB. Defaults to False. .. note:: If no Properties have index=True, all Properties are indexed. """ #: Python type python_type = datetime.datetime def to_db(self, type_system, value): return type_system.database.to_datetime(value) def to_python(self, type_system, value): return type_system.python.to_datetime(value) def is_valid(self, key, value): # how do you assert it's UTC? #Don't use assert except for sanity check during development # (it gets turned to a no-op when you run with python -o), and # don't raise the wrong kind of exception (such as, an AssertionError # when a TypeError is clearly what you mean here). #return type(value) is datetime.datetime return isinstance(value, datetime.datetime) def _coerce(self, value): # Coerce user input to the Python type # Overloaded from Property since this is a special case # http://labix.org/python-dateutil#head-a23e8ae0a661d77b89dfb3476f85b26f0b30349c # return dateutils.parse(value) # Not using parse -- let the client code do that. Expect a UTC dateime object here. # How you going to handle asserts? It's easy with ints. if isinstance(value, Number): # catches unix timestamps dt = to_datetime(value) elif isinstance(value, datetime.datetime): # value passed in was already in proper form dt = value else: # Python 3 unicode/str catchall dt = dateutil.parser.parse(value) #if dt.tzinfo is None: # tz = pytz.timezone('UTC') # dt.replace(tzinfo = tz) return dt
class Date(Property):
    """
    :param fget: Method name that returns a calculated value. Defaults to None.
    :type fget: str

    :param name: Database property name. Defaults to the Property key.
    :type name: str

    :param default: Default property value. Defaults to None.
    :type default: str, int, long, float, list, dict, or Callable

    :param nullable: If True, the Property can be null. Defaults to True.
    :type nullable: bool

    :param indexed: If True, index the Property in the DB. Defaults to False.
    :type indexed: bool

    :ivar fget: Name of the method that gets the calculated Property value.
    :ivar name: Database property name. Defaults to the Property key.
    :ivar default: Default property value. Defaults to None.
    :ivar nullable: If True, the Property can be null. Defaults to True.
    :ivar indexed: If True, index the Property in the DB. Defaults to False.

    .. note:: If no Properties have index=True, all Properties are indexed. 

    """
    #: Python type
    python_type = datetime.date

    def to_db(self, type_system, value):
        return type_system.database.to_date(value)

    def to_python(self, type_system, value):
        return type_system.python.to_date(value)

    def is_valid(self, key, value):
        # how do you assert it's UTC?
        #Don't use assert except for sanity check during development 
        # (it gets turned to a no-op when you run with python -o), and 
        # don't raise the wrong kind of exception (such as, an AssertionError 
        # when a TypeError is clearly what you mean here).
        return isinstance(value, datetime.date)

    def _coerce(self, value):
        # Coerce user input to the Python type
        # Overloaded from Property since this is a special case
        # http://labix.org/python-dateutil#head-a23e8ae0a661d77b89dfb3476f85b26f0b30349c
        # return dateutils.parse(value)
        # Not using parse -- let the client code do that. Expect a UTC dateime object here.
        # How you going to handle asserts? It's easy with ints.
        
        if isinstance(value, Number):
            # catches unix timestamps
            d = to_date(value)
        elif isinstance(value, datetime.date):
            # value passed in was already in proper form
            d = value
        else:
            # Python 3 unicode/str catchall
            d = dateutil.parser.parse(value).date()

        return d