How to use the dispatch.theme.exceptions.InvalidField function in dispatch

def validate(self, data):
        if not data and self.required:
            raise InvalidField('Widget must be selected')

        if not data['id']:
            raise InvalidField("Must specify a widget id")

        try:
            if data['id'] and data['data'] is not None:
                errors = {}
                widget = None

                try:
                    widget = self.get_widget(data['id'])
                except WidgetNotFound:
                    errors['self'] = 'Invalid Widget'

                if widget:
                    for field in widget.fields:
                        if field.name in data['data'] and data['data'][field.name]:
                            try:
                                field.validate(data['data'][field.name])

def validate(self, data):
        if type(data) is not bool:
            raise InvalidField('%s must be boolean' % self.label)

def __init__(self, label, options=[], required=False):
        self.options = options
        self.valid_options = set(option[0] for option in self.options)

        if required and not self.options:
            raise InvalidField('Empty select fields cannot be required fields')

        super(SelectField, self).__init__(label=label, many=False, required=required)

def __init__(self, label, many=False, required=False):
        self.label = label
        self.many = many
        self.required = required

        if self.many:
            self.default = []
        else:
            self.default = None

        self._creation_counter = Field._creation_counter
        Field._creation_counter += 1

        if not isinstance(self.label, str):
            raise InvalidField('Label must be a string')

def validate(self, data):
        if not data and self.required:
            raise InvalidField('Widget must be selected')

        if not data['id']:
            raise InvalidField("Must specify a widget id")

        try:
            if data['id'] and data['data'] is not None:
                errors = {}
                widget = None

                try:
                    widget = self.get_widget(data['id'])
                except WidgetNotFound:
                    errors['self'] = 'Invalid Widget'

                if widget:
                    for field in widget.fields:

def validate(self, data):
        if not data or (isinstance(data, str) and not len(data)):
            if self.required:
                raise InvalidField('%s is required')
            else:
                return

        try:
            if isinstance(data, int):
                value = data
            else:
                value = int(data, base=10)
        except ValueError:
            raise InvalidField('%s must be integer' % self.label)

        if self.min_value is not None and value < self.min_value:
            raise InvalidField('%s must be greater than %d' % (self.label, self.min_value))

        if self.max_value is not None and value > self.max_value:
            raise InvalidField('%s must be less than than %d' % (self.label, self.max_value))

def validate(self, data):
        if self.many:
            if not isinstance(data, list) or not all([is_valid_id(id) for id in data]):
                raise InvalidField('Data must be list of integers or UUIDs')
        else:
            if not is_valid_id(data):
                raise InvalidField('Data must be an integer or UUID')

if widget:
                    for field in widget.fields:
                        if field.name in data['data'] and data['data'][field.name]:
                            try:
                                field.validate(data['data'][field.name])
                            except InvalidField as e:
                                errors[field.name] = str(e)
                        else:
                            if field.required:
                                errors[field.name] = 'This field is required'

                if len(errors):
                    raise InvalidField(json.dumps(errors))
            else:
                raise InvalidField('Invalid Widget Data')
        except InvalidField as e:
            raise e
        except Exception as e:
            raise InvalidField('Problem with widget data %s' % str(e))

if data.get('widget') is not None:

            try:
                widget = ThemeManager.Widgets.get(data['widget'])
            except WidgetNotFound as e:
                errors['widget'] = str(e)
            else:
                for field in widget.fields:

                    field_data = data['data'].get(field.name)

                    if field_data is not None:
                        try:
                            field.validate(field_data)
                        except InvalidField as e:
                            errors[field.name] = str(e)
                    elif field.required:
                        errors[field.name] = '%s is required' % field.label

        if errors:
            raise ValidationError(errors)

        return data

def __init__(self, label, many=False, min_value=None, max_value=None, required=False):
        self.min_value = min_value
        self.max_value = max_value

        if min_value is not None and max_value is not None:
            if min_value > max_value:
                raise InvalidField('IntegerField: min_value must be less than max_value')

        super(IntegerField, self).__init__(label=label, many=many, required=required)