def validate_base(cls, model):
    opts = model._meta

    # raw_id_fields
    if hasattr(cls, 'raw_id_fields'):
        check_isseq(cls, 'raw_id_fields', cls.raw_id_fields)
        for idx, field in enumerate(cls.raw_id_fields):
            f = get_field(cls, model, opts, 'raw_id_fields', field)
            if not isinstance(f, (models.ForeignKey, models.ManyToManyField)):
                raise ImproperlyConfigured("'%s.raw_id_fields[%d]', '%s' must "
                        "be either a ForeignKey or ManyToManyField."
                        % (cls.__name__, idx, field))

    # fields
    if cls.fields: # default value is None
        check_isseq(cls, 'fields', cls.fields)
        for field in cls.fields:
            if field in cls.readonly_fields:
                # Stuff can be put in fields that isn't actually a model field
                # if it's in readonly_fields, readonly_fields will handle the
                # validation of such things.
                continue
            check_formfield(cls, model, opts, 'fields', field)
            try:
                f = opts.get_field(field)
            except models.FieldDoesNotExist:
                # If we can't find a field on the model that matches,
                # it could be an extra field on the form.
                continue
            if isinstance(f, models.ManyToManyField) and not f.rel.through._meta.auto_created:
                raise ImproperlyConfigured("'%s.fields' can't include the ManyToManyField "
                    "field '%s' because '%s' manually specifies "
                    "a 'through' model." % (cls.__name__, field, field))
        if cls.fieldsets:
            raise ImproperlyConfigured('Both fieldsets and fields are specified in %s.' % cls.__name__)
        if len(cls.fields) > len(set(cls.fields)):
            raise ImproperlyConfigured('There are duplicate field(s) in %s.fields' % cls.__name__)

    # fieldsets
    if cls.fieldsets: # default value is None
        check_isseq(cls, 'fieldsets', cls.fieldsets)
        for idx, fieldset in enumerate(cls.fieldsets):
            check_isseq(cls, 'fieldsets[%d]' % idx, fieldset)
            if len(fieldset) != 2:
                raise ImproperlyConfigured("'%s.fieldsets[%d]' does not "
                        "have exactly two elements." % (cls.__name__, idx))
            check_isdict(cls, 'fieldsets[%d][1]' % idx, fieldset[1])
            if 'fields' not in fieldset[1]:
                raise ImproperlyConfigured("'fields' key is required in "
                        "%s.fieldsets[%d][1] field options dict."
                        % (cls.__name__, idx))
            for fields in fieldset[1]['fields']:
                # The entry in fields might be a tuple. If it is a standalone
                # field, make it into a tuple to make processing easier.
                if type(fields) != tuple:
                    fields = (fields,)
                for field in fields:
                    if field in cls.readonly_fields:
                        # Stuff can be put in fields that isn't actually a
                        # model field if it's in readonly_fields,
                        # readonly_fields will handle the validation of such
                        # things.
                        continue
                    check_formfield(cls, model, opts, "fieldsets[%d][1]['fields']" % idx, field)
                    try:
                        f = opts.get_field(field)
                        if isinstance(f, models.ManyToManyField) and not f.rel.through._meta.auto_created:
                            raise ImproperlyConfigured("'%s.fieldsets[%d][1]['fields']' "
                                "can't include the ManyToManyField field '%s' because "
                                "'%s' manually specifies a 'through' model." % (
                                    cls.__name__, idx, field, field))
                    except models.FieldDoesNotExist:
                        # If we can't find a field on the model that matches,
                        # it could be an extra field on the form.
                        pass
        flattened_fieldsets = flatten_fieldsets(cls.fieldsets)
        if len(flattened_fieldsets) > len(set(flattened_fieldsets)):
            raise ImproperlyConfigured('There are duplicate field(s) in %s.fieldsets' % cls.__name__)

    # exclude
    if cls.exclude: # default value is None
        check_isseq(cls, 'exclude', cls.exclude)
        for field in cls.exclude:
            check_formfield(cls, model, opts, 'exclude', field)
            try:
                f = opts.get_field(field)
            except models.FieldDoesNotExist:
                # If we can't find a field on the model that matches,
                # it could be an extra field on the form.
                continue
        if len(cls.exclude) > len(set(cls.exclude)):
            raise ImproperlyConfigured('There are duplicate field(s) in %s.exclude' % cls.__name__)

    # form
    if hasattr(cls, 'form') and not issubclass(cls.form, BaseModelForm):
        raise ImproperlyConfigured("%s.form does not inherit from "
                "BaseModelForm." % cls.__name__)

    # filter_vertical
    if hasattr(cls, 'filter_vertical'):
        check_isseq(cls, 'filter_vertical', cls.filter_vertical)
        for idx, field in enumerate(cls.filter_vertical):
            f = get_field(cls, model, opts, 'filter_vertical', field)
            if not isinstance(f, models.ManyToManyField):
                raise ImproperlyConfigured("'%s.filter_vertical[%d]' must be "
                    "a ManyToManyField." % (cls.__name__, idx))

    # filter_horizontal
    if hasattr(cls, 'filter_horizontal'):
        check_isseq(cls, 'filter_horizontal', cls.filter_horizontal)
        for idx, field in enumerate(cls.filter_horizontal):
            f = get_field(cls, model, opts, 'filter_horizontal', field)
            if not isinstance(f, models.ManyToManyField):
                raise ImproperlyConfigured("'%s.filter_horizontal[%d]' must be "
                    "a ManyToManyField." % (cls.__name__, idx))

    # radio_fields
    if hasattr(cls, 'radio_fields'):
        check_isdict(cls, 'radio_fields', cls.radio_fields)
        for field, val in cls.radio_fields.items():
            f = get_field(cls, model, opts, 'radio_fields', field)
            if not (isinstance(f, models.ForeignKey) or f.choices):
                raise ImproperlyConfigured("'%s.radio_fields['%s']' "
                        "is neither an instance of ForeignKey nor does "
                        "have choices set." % (cls.__name__, field))
            if not val in (HORIZONTAL, VERTICAL):
                raise ImproperlyConfigured("'%s.radio_fields['%s']' "
                        "is neither admin.HORIZONTAL nor admin.VERTICAL."
                        % (cls.__name__, field))

    # prepopulated_fields
    if hasattr(cls, 'prepopulated_fields'):
        check_isdict(cls, 'prepopulated_fields', cls.prepopulated_fields)
        for field, val in cls.prepopulated_fields.items():
            f = get_field(cls, model, opts, 'prepopulated_fields', field)
            if isinstance(f, (models.DateTimeField, models.ForeignKey,
                models.ManyToManyField)):
                raise ImproperlyConfigured("'%s.prepopulated_fields['%s']' "
                        "is either a DateTimeField, ForeignKey or "
                        "ManyToManyField. This isn't allowed."
                        % (cls.__name__, field))
            check_isseq(cls, "prepopulated_fields['%s']" % field, val)
            for idx, f in enumerate(val):
                get_field(cls, model, opts, "prepopulated_fields['%s'][%d]" % (field, idx), f)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/contrib/admin/validation.py/validate_base/original