Python django.core.serializers.base.DeserializationError() Examples

def Deserializer(stream_or_string, **options):
    """
    Deserialize a stream or string of JSON data.
    """
    if not isinstance(stream_or_string, (bytes, six.string_types)):
        stream_or_string = stream_or_string.read()
    if isinstance(stream_or_string, bytes):
        stream_or_string = stream_or_string.decode('utf-8')
    try:
        objects = json.loads(stream_or_string)
        for obj in PythonDeserializer(objects, **options):
            yield obj
    except GeneratorExit:
        raise
    except Exception as e:
        # Map to deserializer error
        six.reraise(DeserializationError, DeserializationError(e), sys.exc_info()[2]) 

def from_json_file(file_path):
        with open(file_path) as f:
            out = serializers.deserialize("json", f.read())  # , ignorenonexistent=True)
            # print(len(out))

            try:
                for o in out:
                    return o.object
            except DeserializationError:
                pass

            raise ProcessingError('Cannot deserialize: %s' % file_path)

        # MySQL utf8mb4 bugfix
        # if instance.raw is not None:
        #     instance.raw = ''.join([char if ord(char) < 128 else '' for char in instance.raw])
        #
        # if instance.text is not None:
        #     instance.text = ''.join([char if ord(char) < 128 else '' for char in instance.text])
        #
        # return instance 

def test_helpful_error_message_invalid_field(self):
        """
        If there is an invalid field value, the error message should contain
        the model associated with it.
        """
        test_string = """[{
            "pk": "1",
            "model": "serializers.player",
            "fields": {
                "name": "Bob",
                "rank": "invalidint",
                "team": "Team"
            }
        }]"""
        expected = "(serializers.player:pk=1) field_value was 'invalidint'"
        with self.assertRaisesMessage(DeserializationError, expected):
            list(serializers.deserialize('json', test_string)) 

def test_helpful_error_message_invalid_pk(self):
        """
        If there is an invalid primary key, the error message should contain
        the model associated with it.
        """
        test_string = """[{
            "pk": "badpk",
            "model": "serializers.player",
            "fields": {
                "name": "Bob",
                "rank": 1,
                "team": "Team"
            }
        }]"""
        with self.assertRaisesMessage(DeserializationError, "(serializers.player:pk=badpk)"):
            list(serializers.deserialize('json', test_string)) 

def test_deserialize_wrong_collection_set(self):
        # This is testing that deserialization is not permitted when collection is placed
        # in incorrect collection set directory.
        serializer = serialize.RecordSerializer(data_dir=self.data_dir)
        serializer.serialize_collection_set(self.collection_set)

        # Partially clean the database in preparation for deserializing
        self.collection1.delete()
        self.collection_set.delete()

        self.assertTrue(os.path.exists(self.collection1_records_path))
        new_collection_set_path = "{}x".format(self.collection_set_path)
        shutil.move(self.collection_set_path, new_collection_set_path)
        self.assertFalse(os.path.exists(self.collection1_records_path))

        deserializer = serialize.RecordDeserializer(data_dir=self.data_dir)
        caught_error = False
        try:
            deserializer.deserialize_collection_set(new_collection_set_path)
        except DeserializationError:
            caught_error = True
        self.assertTrue(caught_error) 

def _get_model_from_node(self, node, attr):
        """
        Helper to look up a model from a <object model=...> or a <field
        rel=... to=...> node.
        """
        model_identifier = node.getAttribute(attr)
        if not model_identifier:
            raise base.DeserializationError(
                "<%s> node is missing the required '%s' attribute" \
                    % (node.nodeName, attr))
        try:
            Model = models.get_model(*model_identifier.split("."))
        except TypeError:
            Model = None
        if Model is None:
            raise base.DeserializationError(
                "<%s> node has invalid model identifier: '%s'" % \
                    (node.nodeName, model_identifier))
        return Model 

def Deserializer(stream_or_string, **options):
    """
    Deserialize a stream or string of JSON data.
    """
    if not isinstance(stream_or_string, (bytes, six.string_types)):
        stream_or_string = stream_or_string.read()
    if isinstance(stream_or_string, bytes):
        stream_or_string = stream_or_string.decode('utf-8')
    try:
        objects = json.loads(stream_or_string)
        for obj in PythonDeserializer(objects, **options):
            yield obj
    except GeneratorExit:
        raise
    except Exception as e:
        # Map to deserializer error
        raise DeserializationError(e) 

def Deserializer(stream_or_string, **options):
    """
    Deserialize a stream or string of YAML data.
    """
    if isinstance(stream_or_string, bytes):
        stream_or_string = stream_or_string.decode('utf-8')
    if isinstance(stream_or_string, six.string_types):
        stream = StringIO(stream_or_string)
    else:
        stream = stream_or_string
    try:
        for obj in PythonDeserializer(yaml.safe_load(stream), **options):
            yield obj
    except GeneratorExit:
        raise
    except Exception as e:
        # Map to deserializer error
        raise DeserializationError(e) 

def load_fixture(apps, schema_editor):
    # Save the old _get_model() function
    old_get_model = python._get_model

    # Define new _get_model() function here, which utilizes the apps argument to
    # get the historical version of a model. This piece of code is directly stolen
    # from django.core.serializers.python._get_model, unchanged.
    def _get_model(model_identifier):
        try:
            return apps.get_model(model_identifier)
        except (LookupError, TypeError):
            raise base.DeserializationError(
                "Invalid model identifier: '%s'" % model_identifier)

    # Replace the _get_model() function on the module, so loaddata can utilize it.
    python._get_model = _get_model

    try:
        # Call loaddata command
        call_command('loaddata', 'estoque_initial_data.json')
    finally:
        # Restore old _get_model() function
        python._get_model = old_get_model 

def _get_model_from_node(self, node, attr):
        """
        Helper to look up a model from a <object model=...> or a <field
        rel=... to=...> node.
        """
        model_identifier = node.getAttribute(attr)
        if not model_identifier:
            raise base.DeserializationError(
                "<%s> node is missing the required '%s' attribute"
                % (node.nodeName, attr))
        try:
            return apps.get_model(model_identifier)
        except (LookupError, TypeError):
            raise base.DeserializationError(
                "<%s> node has invalid model identifier: '%s'"
                % (node.nodeName, model_identifier)) 

def Deserializer(stream_or_string, **options):
    """
    Deserialize a stream or string of YAML data.
    """
    if isinstance(stream_or_string, bytes):
        stream_or_string = stream_or_string.decode('utf-8')
    if isinstance(stream_or_string, six.string_types):
        stream = StringIO(stream_or_string)
    else:
        stream = stream_or_string
    try:
        for obj in PythonDeserializer(yaml.load(stream, Loader=SafeLoader), **options):
            yield obj
    except GeneratorExit:
        raise
    except Exception as e:
        # Map to deserializer error
        six.reraise(DeserializationError, DeserializationError(e), sys.exc_info()[2]) 

def load_fixtures(self, fixtures, apps):
        # Via https://stackoverflow.com/questions/25960850/loading-initial-data-with-django-1-7-and-data-migrations/39743581#39743581
        #  we need to monkeypatch a Django internal in order to provide it with
        #  the correct (old) view of the model
        from django.core.serializers import base, python

        # Define new _get_model() function here, which utilizes the apps argument to
        # get the historical version of a model. This piece of code is directly stolen
        # from django.core.serializers.python._get_model, unchanged.
        def _get_model(model_identifier):
            try:
                return apps.get_model(model_identifier)
            except (LookupError, TypeError):
                raise base.DeserializationError(
                    "Invalid model identifier: '%s'" % model_identifier
                )

        # Save the old _get_model() function
        old_get_model = python._get_model

        # Replace the _get_model() function on the module, so loaddata can utilize it.
        python._get_model = _get_model

        try:
            # From django/test/testcases.py
            for db_name in self._databases_names(include_mirrors=False):
                try:
                    call_command(
                        "loaddata",
                        *fixtures,
                        **{"verbosity": 0, "commit": False, "database": db_name}
                    )
                except Exception:
                    self._rollback_atomics(self.cls_atomics)
                    raise

        finally:
            # Restore old _get_model() function
            python._get_model = old_get_model 

def _get_model(model_identifier):
    """
    Helper to look up a model from an "app_label.module_name" string.
    """
    try:
        Model = models.get_model(*model_identifier.split("."))
    except TypeError:
        Model = None
    if Model is None:
        raise base.DeserializationError("Invalid model identifier: '%s'" % model_identifier)
    return Model 

def _get_model(model_identifier):
    """
    Helper to look up a model from an "app_label.model_name" string.
    """
    try:
        return apps.get_model(model_identifier)
    except (LookupError, TypeError):
        raise base.DeserializationError("Invalid model identifier: '%s'" % model_identifier) 

def test_loaddata_not_found_fields_not_ignore(self):
        """
        Test for ticket #9279 -- Error is raised for entries in
        the serialized data for fields that have been removed
        from the database when not ignored.
        """
        with self.assertRaises(DeserializationError):
            management.call_command(
                'loaddata',
                'sequence_extra',
                verbosity=0,
            ) 

def test_yaml_deserializer_exception(self):
        with self.assertRaises(DeserializationError):
            for obj in serializers.deserialize("yaml", "{"):
                pass 

def test_json_deserializer_exception(self):
        with self.assertRaises(DeserializationError):
            for obj in serializers.deserialize("json", """[{"pk":1}"""):
                pass 

def test_helpful_error_message_for_many2many_non_natural(self):
        """
        Invalid many-to-many keys should throw a helpful error message.
        """
        test_string = """[{
            "pk": 1,
            "model": "serializers.article",
            "fields": {
                "author": 1,
                "headline": "Unknown many to many",
                "pub_date": "2014-09-15T10:35:00",
                "categories": [1, "doesnotexist"]
            }
        }, {
            "pk": 1,
            "model": "serializers.author",
            "fields": {
                "name": "Agnes"
            }
        }, {
            "pk": 1,
            "model": "serializers.category",
            "fields": {
                "name": "Reference"
            }
        }]"""
        expected = "(serializers.article:pk=1) field_value was 'doesnotexist'"
        with self.assertRaisesMessage(DeserializationError, expected):
            list(serializers.deserialize('json', test_string)) 

def test_helpful_error_message_for_many2many_natural1(self):
        """
        Invalid many-to-many keys should throw a helpful error message.
        This tests the code path where one of a list of natural keys is invalid.
        """
        test_string = """[{
            "pk": 1,
            "model": "serializers.categorymetadata",
            "fields": {
                "kind": "author",
                "name": "meta1",
                "value": "Agnes"
            }
        }, {
            "pk": 1,
            "model": "serializers.article",
            "fields": {
                "author": 1,
                "headline": "Unknown many to many",
                "pub_date": "2014-09-15T10:35:00",
                "meta_data": [
                    ["author", "meta1"],
                    ["doesnotexist", "meta1"],
                    ["author", "meta1"]
                ]
            }
        }, {
            "pk": 1,
            "model": "serializers.author",
            "fields": {
                "name": "Agnes"
            }
        }]"""
        key = ["doesnotexist", "meta1"]
        expected = "(serializers.article:pk=1) field_value was '%r'" % key
        with self.assertRaisesMessage(DeserializationError, expected):
            for obj in serializers.deserialize('json', test_string):
                obj.save() 

def test_helpful_error_message_for_many2many_natural2(self):
        """
        Invalid many-to-many keys should throw a helpful error message. This
        tests the code path where a natural many-to-many key has only a single
        value.
        """
        test_string = """[{
            "pk": 1,
            "model": "serializers.article",
            "fields": {
                "author": 1,
                "headline": "Unknown many to many",
                "pub_date": "2014-09-15T10:35:00",
                "meta_data": [1, "doesnotexist"]
            }
        }, {
            "pk": 1,
            "model": "serializers.categorymetadata",
            "fields": {
                "kind": "author",
                "name": "meta1",
                "value": "Agnes"
            }
        }, {
            "pk": 1,
            "model": "serializers.author",
            "fields": {
                "name": "Agnes"
            }
        }]"""
        expected = "(serializers.article:pk=1) field_value was 'doesnotexist'"
        with self.assertRaisesMessage(DeserializationError, expected):
            for obj in serializers.deserialize('json', test_string, ignore=False):
                obj.save() 

def test_loaddata_not_found_fields_not_ignore(self):
        """
        Test for ticket #9279 -- Error is raised for entries in
        the serialized data for fields that have been removed
        from the database when not ignored.
        """
        with self.assertRaises(DeserializationError):
            management.call_command(
                'loaddata',
                'sequence_extra',
                verbosity=0,
            ) 

def _handle_object(self, node):
        """
        Convert an <object> node to a DeserializedObject.
        """
        # Look up the model using the model loading mechanism. If this fails,
        # bail.
        Model = self._get_model_from_node(node, "model")

        # Start building a data dictionary from the object.
        # If the node is missing the pk set it to None
        if node.hasAttribute("pk"):
            pk = node.getAttribute("pk")
        else:
            pk = None

        data = {Model._meta.pk.attname : Model._meta.pk.to_python(pk)}

        # Also start building a dict of m2m data (this is saved as
        # {m2m_accessor_attribute : [list_of_related_objects]})
        m2m_data = {}

        # Deseralize each field.
        for field_node in node.getElementsByTagName("field"):
            # If the field is missing the name attribute, bail (are you
            # sensing a pattern here?)
            field_name = field_node.getAttribute("name")
            if not field_name:
                raise base.DeserializationError("<field> node is missing the 'name' attribute")

            # Get the field from the Model. This will raise a
            # FieldDoesNotExist if, well, the field doesn't exist, which will
            # be propagated correctly.
            field = Model._meta.get_field(field_name)

            # As is usually the case, relation fields get the special treatment.
            if field.rel and isinstance(field.rel, models.ManyToManyRel):
                m2m_data[field.name] = self._handle_m2m_field_node(field_node, field)
            elif field.rel and isinstance(field.rel, models.ManyToOneRel):
                data[field.attname] = self._handle_fk_field_node(field_node, field)
            else:
                if field_node.getElementsByTagName('None'):
                    value = None
                else:
                    value = field.to_python(getInnerText(field_node).strip())
                data[field.name] = value

        # Return a DeserializedObject so that the m2m data has a place to live.
        return base.DeserializedObject(Model(**data), m2m_data) 

def _handle_object(self, node):
        """
        Convert an <object> node to a DeserializedObject.
        """
        # Look up the model using the model loading mechanism. If this fails,
        # bail.
        Model = self._get_model_from_node(node, "model")

        # Start building a data dictionary from the object.
        data = {}
        if node.hasAttribute('pk'):
            data[Model._meta.pk.attname] = Model._meta.pk.to_python(
                node.getAttribute('pk'))

        # Also start building a dict of m2m data (this is saved as
        # {m2m_accessor_attribute : [list_of_related_objects]})
        m2m_data = {}

        field_names = {f.name for f in Model._meta.get_fields()}
        # Deserialize each field.
        for field_node in node.getElementsByTagName("field"):
            # If the field is missing the name attribute, bail (are you
            # sensing a pattern here?)
            field_name = field_node.getAttribute("name")
            if not field_name:
                raise base.DeserializationError("<field> node is missing the 'name' attribute")

            # Get the field from the Model. This will raise a
            # FieldDoesNotExist if, well, the field doesn't exist, which will
            # be propagated correctly unless ignorenonexistent=True is used.
            if self.ignore and field_name not in field_names:
                continue
            field = Model._meta.get_field(field_name)

            # As is usually the case, relation fields get the special treatment.
            if field.rel and isinstance(field.rel, models.ManyToManyRel):
                m2m_data[field.name] = self._handle_m2m_field_node(field_node, field)
            elif field.rel and isinstance(field.rel, models.ManyToOneRel):
                data[field.attname] = self._handle_fk_field_node(field_node, field)
            else:
                if field_node.getElementsByTagName('None'):
                    value = None
                else:
                    value = field.to_python(getInnerText(field_node).strip())
                data[field.name] = value

        obj = base.build_instance(Model, data, self.db)

        # Return a DeserializedObject so that the m2m data has a place to live.
        return base.DeserializedObject(obj, m2m_data)