Improve Validation & Formalisation of Hydra objects

[knoxsp]

the JSONObject currently returns 'None' when acessing an attribute that doesn't exist. If we change this to throw an AttributeError (correct) then we need a way to formalise what attributes are allowed on an incoming object. One solution could be:

#PARENT SCHEMA
class HydraSchema():

    def validate(self, k, v):
        pass

    def __init__(self, parent=None):
        super(Project, self).__init__()

        if parent is None:
            return

        for k, v in parent.items():
            #validate k versus v
            validate(k, v)
            setattr(self, k, v)

#HYDRA SCHEMA
class HydraProject(JSONObject):
    _properties = {
        ('id',          Integer(default=None)),
        ('name',        Unicode(default=None)),
        ('description', Unicode(default=None)),
        ('status',      Unicode(default='A', pattern="[AX]")),
        ('cr_date',     Unicode(default=None)),
        ('created_by',  Integer(default=None)),
        ('attributes',  SpyneArray(ResourceAttr)),
        ('attribute_data', SpyneArray(ResourceScenario)),

    }

SpyneProject = make_spyne_resource(HydraProject)

#SPYNE SCHEMA
class SpyneProject(Resource):
    """
   - **id**          Integer(default=None)
   - **name**        Unicode(default=None)
   - **description** Unicode(default=None)
   - **status**      Unicode(default='A')
   - **cr_date**     Unicode(default=None)
   - **created_by**  Integer(default=None)
   - **attributes**  SpyneArray(ResourceAttr)
   - **attribute_data** SpyneArray(ResourceScenario)
    """
    _type_info = [
        ('id',          Integer(default=None)),
        ('name',        Unicode(default=None)),
        ('description', Unicode(default=None)),
        ('status',      Unicode(default='A', pattern="[AX]")),
        ('cr_date',     Unicode(default=None)),
        ('created_by',  Integer(default=None)),
        ('attributes',  SpyneArray(ResourceAttr)),
        ('attribute_data', SpyneArray(ResourceScenario)),
    ]

[jetuk]

We discussed using marshmallow for the schema declaration. This needs a proof of concept first before accepting as an idea.