findCustomScalarOption but for repeated options?

[Jayatubi]

It is valid to define a repeated options for a message such as:

extend google.protobuf.MessageOptions {
    repeated string bar = 10001;
}

message FooMessage {
   option(bar) = "hello";
   option(bar) = "world;
   ...
}

However, the function findCustomScalarOption could be used only to retrieve the first option since it was implemented as:

function createBinaryReader(desc, extensionNumber) {
    const opt = desc.proto.options;
    let reader = undefined;
    if (opt !== undefined) {
        const unknownFields = protobuf_1.proto3.bin.listUnknownFields(opt);
        /* 
           This `unknownFields` contains all the repeated options attached to a message, with a same number.
           But only the first matched one will be returned
        */
        const field = unknownFields.find((f) => f.no === extensionNumber);
        if (field) {
            reader = new protobuf_1.BinaryReader(field.data);
        }
    }
    return reader;
}

How about to provide a new function, maybe named findCustomRepeatedOptions, to retrieve all the matched options?

For example:

function createRepeatedBinaryReaders(desc, extensionNumber) {
  const opt = desc.proto.options;
  let readers = undefined;
  if (opt !== undefined) {
    const unknownFields = protobuf_1.proto3.bin.listUnknownFields(opt);
    readers = unknownFields
      .filter((f) => f.no === extensionNumber)
      .map(f => new protobuf_1.BinaryReader(field.data))
  }
  return readers;
}

[smaye81]

Hi @Jayatubi. You can retrieve repeated options using a message wrapper and the findCustomMessageOption function. For example:

// custom_options.proto
extend google.protobuf.MethodOptions {
  optional FooOptions foo_method_option = 50007;
}

message FooOptions {
  repeated string many = 1;
}

// foo_service.proto
import "custom_options.proto";

service FooService {
  rpc Get(GetRequest) returns (GetResponse) {
    option (foo_method_option) = { 
        many: ["a", "b", "c"],
    };
  }
}

You can retrieve the options using a generated type by first generating the file which defines the custom option type. Then, import and pass this type to the findCustomMessageOption function.

import { FooOptions } from "./gen/proto/custom_options_pb.js";

const option = findCustomMessageOption(method, 50007, FooOptions)

console.log(option);
/*
 * {
 *     many: ["a", "b", "c"],
 * }
 */

For more info, check out our plugin docs

[Jayatubi]

Hi @Jayatubi. You can retrieve repeated options using a message wrapper and the findCustomMessageOption function. For example:

// custom_options.proto
extend google.protobuf.MethodOptions {
  optional FooOptions foo_method_option = 50007;
}

message FooOptions {
  repeated string many = 1;
}

// foo_service.proto
import "custom_options.proto";

service FooService {
  rpc Get(GetRequest) returns (GetResponse) {
    option (foo_method_option) = { 
        many: ["a", "b", "c"],
    };
  }
}

You can retrieve the options using a generated type by first generating the file which defines the custom option type. Then, import and pass this type to the findCustomMessageOption function.

import { FooOptions } from "./gen/proto/custom_options_pb.js";

const option = findCustomMessageOption(method, 50007, FooOptions)

console.log(option);
/*
 * {
 *     many: ["a", "b", "c"],
 * }
 */

For more info, check out our plugin docs

The wrapper message option looks like but I think a plain repeated options should also be useful.

No need to change any of current interfaces. Just add a new one would be better.

[smaye81]

Yeah, understood. We actually explicitly opted against this for now to keep the API simpler and feel that the message wrapper is a viable alternative. Going to close this for now, since I don't see us implementing this anytime soon, but we will definitely reopen if we decide to revisit.

[timostamm]

@Jayatubi, the next release will support extensions. They can be used to retrieve repeated custom options as well. See #666 and #669.