```
def validate_schema(schema_class):
assert issubclass(schema_class, Schema) # Marshmallow

def decorator(view_func):
@functools.wraps(view_func)
def inner(*args, **kwargs):

if request.method == "GET":
form_data = request.args
else:
form_data = request.json
try:
data = schema_class().load(form_data)
_request_ctx_stack.top.schema_data = data
except ValidationError as e:
return error_json(
ResponseCode.ERROR, parse_err_messages(e), data=e.messages
)
return view_func(*args, **kwargs)

return inner

return decorator

@validate_schema(val.PostTestSchema)
def api_test():
device_id = current_schema_data.get('device_id')
```