commit | 18ab9c733b940f2c5bead7491821e9751da8972b | [log] [tgz] |
---|---|---|
author | Brian Slesinsky <skybrian@google.com> | Tue Jul 19 11:19:53 2016 -0700 |
committer | Brian Slesinsky <skybrian@google.com> | Tue Jul 19 11:19:53 2016 -0700 |
tree | 15cdacbd0e037e3c98f57ceecac9a3b52ae66841 | |
parent | a0475093622526658bef907b2c968a9b7221e3f5 [diff] |
Add dart options for override annotations. These make it possible to tag generated getters, setters, clearX() and hasX() methods with "@override". R=skybrian@google.com Review URL: https://chromiumcodereview.appspot.com//2150323002 .
This repository provides a plugin for the protoc compiler. It generates Dart files for working with data in protocol buffers format. At this time we only support proto2, but proto3 may work in simple cases due to backwards compatibility.
To compile a .proto file, you must use the ‘protoc’ command which is installed separately. Protobuf 2.6.1 or above is recommended. Many features may still work as far back as Protobuf 2.5.0 but we are no longer testing this.
The generated files are pure Dart code that run in either in the Dart VM or in a browser (using dart2js). They depend the protobuf Dart package. A Dart project that includes generated files should add “protobuf” to its pubspec.yaml file.
Note: currently the workflow is POSIX-oriented.
To build standalone protoc
plugin:
pub install
to install all dependeciesmake build-plugin
. That will create a file out/protoc-gen-dart
which is a pluginPATH
or passing directly with protoc
's --plugin
option.Please, remember that the plugin is pure Dart script and requires the presence of dart
executable in your PATH
.
When both the dart
executable and out/protoc-gen-dart
are in the PATH
the protocol buffer compiler can be invoked to generate like this:
$ protoc --dart_out=. test.proto
The protocol buffer compiler accepts options for each plugin. For the Dart plugin, these options are passed together with the --dart_out
option. The individial options are separated using comma, and the final output directive is separated from the options using colon. Pass options <option 1>
and <option 2>
like this:
--dart_out="<option 1>,<option 2>:."
The protocol buffer compiler produces several files for each .proto
file it compiles. In some cases this is not exactly what is needed, e.g one would like to create new libraries which exposes the objects in these libraries or create new librares combining object definitions from several .proto
libraries into one.
The best way to aproach this is to create the new libraries needed and re-export the relevant protocol buffer classes.
Say we have the file m1.proto
with the following content
message M1 { optional string a; }
and m2.proto
containing
message M2 { optional string b; }
Compiling these to Dart will produce two libraries in m1.pb.dart
and m2.pb.dart
. The following code shows a library M which combines these two protocol buffer libraries, exposes the classes M1
and M2
and adds som additional methods.
library M; import "m1.pb.dart"; import "m2.pb.dart"; export "m1.pb.dart" show M1; export "m2.pb.dart" show M2; M1 createM1() => new M1(); M2 createM2() => new M2();
Here are some ways to get protoc:
apt-get install protobuf-compiler
brew install protobuf
If the version installed this way doesn't work, an alternative is to compile protoc from source.
Remember to run the tests. That is as easy as make run-tests
.
The default way of running the Dart protoc plugin is through the generated out/protoc-gen-dart
script. However when run this way the Dart code is assembled into one large Dart file using dart2dart. To run with the actual source in the repository create an executable script called protoc-gen-dart
with the following content:
#! /bin/bash dart bin/protoc_plugin.dart
When running protoc just ensure that this script is first when PATH is searched. If the script is in the current directory run protoc
like this:
$ PATH=.:$PATH protoc --dart_out=. test.proto
It is also possible to call the script something else than protoc-gen-dart
and then refer directly to it using the --plugin
option. If the script is called dart-plugin
run protoc
like this:
$ protoc --plugin=protoc-gen-dart=./plugin --dart_out=. test.proto