Custom protoc plugin parsing not working for custom options - protocol-buffers

Question

I am trying to write a protoc plugin that requires me to use custom options. I defined my custom option as shown in the example (https://developers.google.com/protocol-buffers/docs/proto#customoptions):
import "google/protobuf/descriptor.proto";
extend google.protobuf.MessageOptions {
string my_option = 51234;
}
I use it as follows:
message Hello {
bool greeting = 1;
string name = 2;
int32 number = 3;
option (my_option) = "telephone";
}
However, when I read the parsed request, the options field is empty for the "Hello" message.
I am doing the following to read
data = sys.stdin.read()
request = plugin.CodeGeneratorRequest()
request.ParseFromString(data)
When I print "request," it just gives me this
message_type {
name: "Hello"
field {
name: "greeting"
number: 1
label: LABEL_REQUIRED
type: TYPE_BOOL
json_name: "greeting"
}
field {
name: "name"
number: 2
label: LABEL_REQUIRED
type: TYPE_STRING
json_name: "name"
}
field {
name: "number"
number: 3
label: LABEL_OPTIONAL
type: TYPE_INT32
json_name: "number"
}
options {
}
}
As seen, the options field is empty even though I defined options in my .proto file. Is my syntax incorrect for defining custom options? Or could it be a problem with my version of protoc?

Answer 1

I'm making my protobuf python plugin.
I also got the problem like yours and i have found a solution for that.
Put your custom options to a file my_custom.proto
Use protoc to gen a python file from my_custom.proto => my_custom_pb2.py
In your python plugin code, import my_custom_pb2.py import my_custom_pb2

Answer 2

Turns out you need to have the _pb2.py file imported for the .proto file in which the custom option is defined. For example, it you are parsing a file (using ParseFromString) called example.proto which uses a custom option defined in option.proto, you must import option_pb2.py in the Python file that calls ParseFromString.