Example of protobuf generation

[byrnedo]

Is it possible to generate php from proto files with Meta? Would be great to see an example workflow.

[jakubkulhan]

It is possible, e.g. everything in gen-src/ directory in this repository is generated from .proto files here.

Check out this repository, run composer install and add bin/ to your $PATH. Then use official protoc compiler, e.g.:

protoc -I./proto --php_out=gen-src proto/skrz/meta/fixtures/protobuf/interoperability.proto

protoc will parse .proto file and then pass it to protoc-gen-php, which will generate the source code for messages & enums (it does not generate any interfaces for services).

You can also add @spec comment above package in .proto file to use custom MetaSpec class - https://github.com/skrz/meta/blob/master/proto/skrz/meta/fixtures/protobuf/interoperability.proto#L3

[byrnedo]

Thanks, will give this all a try.

[byrnedo]

Finally got round to this. I can't seem to get it to work yet.
My setup is 1 proto file which has a field which is of a type defined in another proto file.
This other proto file lives in a vendor dir in my project

My message proto:

package mypkg;

import "github.com/byrnedo/apibase/natsio/protobuf/nats.proto";
import "github.com/gogo/protobuf/gogoproto/gogo.proto";


message Request {
    optional protobuf.NatsContext context = 1;
    ...
}

The command:

protoc --php_out=gen-src  --proto_path ../../vendor/ --proto_path ./ --proto_path ../../vendor/github.com/gogo/protobuf/protobuf request.proto

The error:

PHP Fatal error:  Uncaught exception 'ReflectionException' with message 'Class Protobuf\NatsContext does not exist' in /home/donal/dev/github/meta/src/Skrz/Meta/Reflection/MixedType.php:133
Stack trace:
#0 /home/donal/dev/github/meta/src/Skrz/Meta/Reflection/MixedType.php(133): ReflectionClass->__construct('Protobuf\\NatsCo...')
...

Must I compile the other proto file first? I did try that but I got

[byrnedo]

Ah ok, I think it's because I have multiple messages per file? Is there support for that?

Edit: I got round the issue by making one of the messages in my file to be embedded declaration.

[jakubkulhan]

It seems that message classes are not properly generated before skrz/meta tries to generate *Meta classes. Unfortunately, this isn't tested well, because I mostly used @ProtobufField annotations on existing PHP classes.