bfabric_flask.py errors when order has no associated samples

[wolski]

I am using bfrabic_flask.py to query b-fabric

When running the R code from bfabricShiny

fromJSON("http://localhost:5000/sample/22342")
Error in open.connection(con, "rb") : HTTP error 500.

The flask server (bfabric_shiny.py) produces this error.
This order has no samples. It might be easier to handle the problem if we get an empty list as a result, instead of an error. Not sure.

Traceback (most recent call last):
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 2464, in __call__
    return self.wsgi_app(environ, start_response)
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 2450, in wsgi_app
    response = self.handle_exception(e)
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 1867, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\_compat.py", line 39, in reraise
    raise value
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Users\wewol\AppData\Roaming\Python\Python38\site-packages\flask\app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\wewol\prog\bfabricPy\bfabric\scripts\bfabric_flask.py", line 291, in get_all_sample
    for sample in samples:
TypeError: 'NoneType' object is not iterable