Class discoverability

[Ubaldo Huerta]

Say I want to define a message that includes another message (in case you'd like to have a list, for example, but it's irrelevant)

class MyMessage(messages.Message):

    rewards = messages.MessageField(MyOtherMessage, 1, repeated=True)

Well, this works fine only if MyOtherMessage is not a nested class in a module. 

# This works fine

class MyOtherMessage(messages.Message):

   ......

class Foo:

   # This doesn't work

   class MyOtherMessage(messages.Message):

   ......

   

Not that using a string form for MyMessage won't help you either

class MyMessage(messages.Message):

     # This doesn't work either

    rewards = messages.MessageField("Foo.MyOtherMessage", 1, repeated=True)

[Rafe Kaplan]

It should work if MyOtherMessage is nested within another message.
For example, if Foo is a message.

The reason that it cannot work otherwise is that the name you are
passing in is meant to be a protorpc fully qualified name. It needs
to be the same name (relative to MyMessage or absolute) that the
client will use. That means protorpc explicitly rejects Foo as a
container for the class in this case.