Set up spyne to skip a field which is not present in SOAP request?

Question

I have a SQLALchemy model with such a column:

updated_at = Column(DateTime, nullable=False, server_default=func.now(),
                        onupdate=func.now())

Which generates WSDL:

<xs:element name="updated_at" type="xs:dateTime" minOccurs="0"/>

In the update request updated_at field is missing, and spyne maps its value to None causing this:

IntegrityError: (IntegrityError) null value in column "updated_at" violates not-null constraint
 'UPDATE subcsription SET updated_at=%(updated_at)s WHERE subcsription.id = %(subcsription_id)s' {'subcsription_id': 27, 'updated_at': None}

How can i set up spyne to skip the field at all when it is not passed in SOAP request?

Burak Arslan · Accepted Answer · 2013-07-20T11:09:18.260

Your interface and your database schema don't need to match 1-to-1. You can define a separate object that doesn't have the updated_at member and use it as the input type in your service definition. E.g.

class SomeObject(TableModel):
    __tablename__ = 'some_table'

    id = UnsignedInteger64(pk=True)
    updated_at = DateTime(server_default=func.now(), onupdate=func.now())
    some_data = Unicode

class SomeWriteObject(TableModel):
    __tablename__ = 'some_table'

    id = UnsignedInteger64(pk=True)
    some_data = Unicode

# or, you could do this:
class SomeWriteObject(TableModel):
    __tablename__ = 'some_table'
    _type_info = [ (k,v) for k,v in SomeObject._type_info.items()
                                                  if not k in ('updated_at',) ]
class SomeService(ServiceBase):
    @rpc(SomeWriteObject, _returns=UnsignedInteger64)
    def add_some_object(ctx, obj):
        ctx.udc.session.add(obj)
        ctx.udc.session.commit()
        return obj.id

This way updated_at will be left out in the insert query which will leave it to the database to fill that field according to your instructions.

This means manually specifying fields and excluding some of them? Because right now fields are automatically extracted from a SQLALchemy model. I ended up monkey-patching spyne to not set field values of an incoming object if they were not passed in a SOAP request. This also solves a problem, when a spyne field is optional, but it was not passed in SOAP request, causing it to be overwritten with `None`. — warvariuc, Jul 19 '13 at 04:09
This doesn't need to be done manually, see my edit. Also, could you share your monkey-patching code in some github gist? It could help others. — Burak Arslan, Jul 20 '13 at 11:12

Set up spyne to skip a field which is not present in SOAP request?

1 Answers1