Source code for spyne.model.table

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# Lesser General Public License for more details.
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"""This module is DEPRECATED. Create your own TableModel using
:func:`spyne.model.complex.TTableModel`

Here's an example way of using the :class:`spyne.model.table.TableModel`: ::

    class User(TableModel, DeclarativeBase):
        __namespace__ = 'spyne.examples.user_manager'
        __tablename__ = 'spyne_user'

        user_id = Column(sqlalchemy.Integer, primary_key=True)
        user_name = Column(sqlalchemy.String(256))
        first_name = Column(sqlalchemy.String(256))
        last_name = Column(sqlalchemy.String(256))

Defined this way, SQLAlchemy objects are regular Spyne objects that can be
used anywhere the regular Spyne types go. The definition for the `User` object
is quite similar to vanilla SQLAlchemy declarative syntax, save for two
elements:

#. The object also bases on :class:`spyne.model.table.TableModel`, which
   bridges SQLAlchemy and Spyne types.
#. It has a namespace declaration, which is just so the service looks good
   on wsdl.

The SQLAlchemy integration is far from perfect at the moment:

* SQL constraints are not reflected to the interface document.
* It's not possible to define additional constraints for the Spyne schema.
* Object attributes defined by mechanisms other than Column and limited
  uses of `relationship` (no string arguments) are not supported.

If you need any of the above features, you need to separate the Spyne and
SQLAlchemy object definitions.

Spyne makes it easy (to an extent) with the following syntax: ::

    class AlternativeUser(TableModel, DeclarativeBase):
        __namespace__ = 'spyne.examples.user_manager'
        __table__ = User.__table__

Here, The AlternativeUser object is automatically populated using columns from
the table definition.
"""


import logging
logger = logging.getLogger(__name__)

import sqlalchemy

from spyne.util.six import add_metaclass

from sqlalchemy import Column
from sqlalchemy.orm import RelationshipProperty
from sqlalchemy.ext.declarative import DeclarativeMeta
from sqlalchemy.dialects.postgresql import UUID

from spyne.model import primitive
from spyne.model import binary
from spyne.model import complex
from spyne.model.complex import Array
from spyne.model.complex import TypeInfo
from spyne.model.complex import ComplexModelBase
from spyne.model.complex import ComplexModelMeta


_type_map = {
    sqlalchemy.Text: primitive.String,
    sqlalchemy.String: primitive.String,
    sqlalchemy.Unicode: primitive.String,
    sqlalchemy.UnicodeText: primitive.String,

    sqlalchemy.Float: primitive.Float,
    sqlalchemy.Numeric: primitive.Decimal,
    sqlalchemy.BigInteger: primitive.Integer,
    sqlalchemy.Integer: primitive.Integer,
    sqlalchemy.SmallInteger: primitive.Integer,

    sqlalchemy.Binary: binary.ByteArray,
    sqlalchemy.LargeBinary: binary.ByteArray,
    sqlalchemy.Boolean: primitive.Boolean,
    sqlalchemy.DateTime: primitive.DateTime,
    sqlalchemy.Date: primitive.Date,
    sqlalchemy.Time: primitive.Time,

    sqlalchemy.orm.relation: complex.Array,

    UUID: primitive.String(pattern="%(x)s{8}-"
                                   "%(x)s{4}-"
                                   "%(x)s{4}-"
                                   "%(x)s{4}-"
                                   "%(x)s{12}" % {'x': '[a-fA-F0-9]'},
                           name='uuid')
}


def _process_item(v):
    """This function maps sqlalchemy types to spyne types."""

    rpc_type = None
    if isinstance(v, Column):
        if isinstance(v.type, sqlalchemy.Enum):
            if v.type.convert_unicode:
                rpc_type = primitive.Unicode(values=v.type.enums)
            else:
                rpc_type = primitive.String(values=v.type.enums)

        elif v.type in _type_map:
            rpc_type = _type_map[v.type]

        elif type(v.type) in _type_map:
            rpc_type = _type_map[type(v.type)]

        else:
            raise Exception("soap_type was not found. maybe _type_map needs a "
                            "new entry. %r" % v)

    elif isinstance(v, RelationshipProperty):
        v.enable_typechecks = False
        # FIXME: Distinguish between *ToMany and *ToOne relationship.
        # rpc_type = v.argument
        rpc_type = Array(v.argument)

    return rpc_type


def _is_interesting(k, v):
    if k.startswith('__'):
        return False

    if isinstance(v, Column):
        return True

    if isinstance(v, RelationshipProperty):
        if getattr(v.argument, '_type_info', None) is None:
            logger.warning("the argument to relationship should be a reference "
                           "to the real column, not a string.")
            return False

        else:
            return True


class TableModelMeta(DeclarativeMeta, ComplexModelMeta):
[docs]    """This class uses the information in class definition dictionary to build
    the _type_info dictionary that spyne relies on. It otherwise leaves
    SQLAlchemy and its information alone.
    """

    def __new__(cls, cls_name, cls_bases, cls_dict):
        if cls_dict.get("__type_name__", None) is None:
            cls_dict["__type_name__"] = cls_name

        if cls_dict.get("_type_info", None) is None:
            cls_dict["_type_info"] = _type_info = TypeInfo()

            def check_mixin_inheritance(bases):
                for b in bases:
                    check_mixin_inheritance(b.__bases__)

                    for k, v in vars(b).items():
                        if _is_interesting(k, v):
                            _type_info[k] = _process_item(v)

            check_mixin_inheritance(cls_bases)

            def check_same_table_inheritance(bases):
                for b in bases:
                    check_same_table_inheritance(b.__bases__)

                    table = getattr(b, '__table__', None)

                    if not (table is None):
                        for c in table.c:
                            _type_info[c.name] = _process_item(c)

            check_same_table_inheritance(cls_bases)

            # include from table
            table = cls_dict.get('__table__', None)
            if not (table is None):
                for c in table.c:
                    _type_info[c.name] = _process_item(c)

            # own attributes
            for k, v in cls_dict.items():
                if _is_interesting(k, v):
                    _type_info[k] = _process_item(v)

        return super(TableModelMeta, cls).__new__(cls, cls_name, cls_bases, cls_dict)


@add_metaclass(TableModelMeta)
class TableModel(ComplexModelBase):
[docs]    """The main base class for complex types shared by both SQLAlchemy and
    spyne. Classes that inherit from this class should also inherit from
    an sqlalchemy.declarative base class. See the :ref:`manual-sqlalchemy`
    section for more info.
    """

    _decl_class_registry = {}