| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| part of protoc; |
| |
| /// Helper function implementing a generic option parser that reads |
| /// `request.parameters` and treats each token as either a flag ("name") or a |
| /// key-value pair ("name=value"). For each option "name", it looks up whether a |
| /// [SingleOptionParser] exists in [parsers] and delegates the actual parsing of |
| /// the option to it. Returns `true` if no errors were reported. |
| bool genericOptionsParser(CodeGeneratorRequest request, |
| CodeGeneratorResponse response, Map<String, SingleOptionParser> parsers) { |
| var parameter = request.parameter != null ? request.parameter : ''; |
| var options = parameter.trim().split(','); |
| var errors = []; |
| |
| for (var option in options) { |
| option = option.trim(); |
| if (option.isEmpty) continue; |
| void reportError(String details) { |
| errors.add('Error found trying to parse the option: $option.\n$details'); |
| } |
| |
| var nameValue = option.split('='); |
| if (nameValue.length != 1 && nameValue.length != 2) { |
| reportError('Options should be a single token, or a name=value pair'); |
| continue; |
| } |
| var name = nameValue[0].trim(); |
| var parser = parsers[name]; |
| if (parser == null) { |
| reportError('Unknown option ($name).'); |
| continue; |
| } |
| |
| var value = nameValue.length > 1 ? nameValue[1].trim() : null; |
| parser.parse(name, value, reportError); |
| } |
| |
| if (errors.length == 0) return true; |
| |
| response.error = errors.join('\n'); |
| return false; |
| } |
| |
| /// Options expected by the protoc code generation compiler. |
| class GenerationOptions { |
| final bool useGrpc; |
| |
| GenerationOptions({this.useGrpc = false}); |
| } |
| |
| /// A parser for a name-value pair option. Options parsed in |
| /// [genericOptionsParser] delegate to instances of this class to |
| /// parse the value of a specific option. |
| abstract class SingleOptionParser { |
| /// Parse the [name]=[value] value pair and report any errors to [onError]. If |
| /// the option is a flag, [value] will be null. Note, [name] is commonly |
| /// unused. It is provided because [SingleOptionParser] can be registered for |
| /// multiple option names in [genericOptionsParser]. |
| void parse(String name, String value, onError(String details)); |
| } |
| |
| class GrpcOptionParser implements SingleOptionParser { |
| bool grpcEnabled = false; |
| |
| @override |
| void parse(String name, String value, onError(String details)) { |
| if (value != null) { |
| onError('Invalid grpc option. No value expected.'); |
| return; |
| } |
| grpcEnabled = true; |
| } |
| } |
| |
| /// Parser used by the compiler, which supports the `rpc` option (see |
| /// [RpcOptionParser]) and any additional option added in [parsers]. If |
| /// [parsers] has a key for `rpc`, it will be ignored. |
| GenerationOptions parseGenerationOptions( |
| CodeGeneratorRequest request, CodeGeneratorResponse response, |
| [Map<String, SingleOptionParser> parsers]) { |
| final newParsers = <String, SingleOptionParser>{}; |
| if (parsers != null) newParsers.addAll(parsers); |
| |
| final grpcOptionParser = new GrpcOptionParser(); |
| newParsers['grpc'] = grpcOptionParser; |
| |
| if (genericOptionsParser(request, response, newParsers)) { |
| return new GenerationOptions(useGrpc: grpcOptionParser.grpcEnabled); |
| } |
| return null; |
| } |