Finding enum type in a protobuffer

Question

Good evening all,

Writing an application in IronPython that will act as a message spoofer for a system that has not been developed far enough to test for our system. Part of the application is a set of tables that show values for messages and commands. In the case of commands there are some fields of our commands that have enum values. The command table is to have a drop-down box with those enum options in it.

My approach is to create a DataSet for each of our messages. The DataSet has a DataTable that had the message fields in it and the message values. It also has a table for each enum type in the message. So, the following code is what I use to figure out if the field is a normal field or an enum field.

 msg = mpas.M120()
 msg_fields = msg.DESCRIPTOR.fields
 for field in msg_fields:
        fieldEnumType = msg.DESCRIPTOR.fields_by_name[field.name].enum_type
        print("{} --> EnumType: {}".format(field.name, fieldEnumType.name if fieldEnumType != None else 'None'))

I have also found that this works for me as well:

 msg = mpas.M120()
 msg_fields = msg.DESCRIPTOR.fields
 for k,v in msg.DESCRIPTOR.fields_by_name.items():
        print ("{} --> {}".format(k, ((v.enum_type).name if v.enum_type != None else 'None')))

What I will get from this is the name of the enum for each of the enum fields. I now want to be able to get a list of all of the values for each of the enum fields found. Here is the trick, enums that are used by a certain message and only that message are defined at the message level (i.e. mpas.M120().. Enums that are used by other messages are defined at the top level (i.e. mpas..

So, how would I go about finding the values for these enums so I can populate my drop-down boxes? I have been working on this for the better part of a day now and I cannot figure it out.

Thanks in advance...

Answer 1

You've already found v.enum_type, which is the EnumDescriptor corresponding to the field's enum type. You are getting name from here, but this object also contains a list of values. See the documentation here:

https://developers.google.com/protocol-buffers/docs/reference/python/google.protobuf.descriptor.EnumDescriptor-class