JS generator missing jspb.generate_from_object option

[hochhaus]

The comment for jspb.Message.GENERATE_FROM_OBJECT states:

 *     NOTE: By default no protos actually have a fromObject method. You need to
 *     add the jspb.generate_from_object options to the proto definition to
 *     activate the feature.

However, no such option is currently implemented in the open sourced version. I see the code which generates output for this option (GenerateClassFromObject) but it is invoked 0 times.

~/protobuf$ grep -r GenerateClassFromObject .
./src/google/protobuf/compiler/js/js_generator.cc:void Generator::GenerateClassFromObject(const GeneratorOptions& options,
./src/google/protobuf/compiler/js/js_generator.h:  void GenerateClassFromObject(const GeneratorOptions& options,

Can the jspb.generate_from_object option be open sourced?

[hochhaus]

Also, the jspb.generate_xid option appears to be missing as well.

/**
 * The xid of this proto type (The same for all instances of a proto). Provides
 * a way to identify a proto by stable obfuscated name.
 * @see {xid}.
 * Available if {@link jspb.generate_xid} is added as a Message option to
 * a protocol buffer.
 * @const {!xid.String|undefined} The xid or undefined if message is
 *     annotated to generate the xid.
 */
jspb.Message.prototype.messageXid;

[hochhaus]

@xfxyjwf Any chance this bug could be addressed prior to the beta 4 release? It is a large issue for certain use cases of the JS implementation.

[pcj]

+1

[hochhaus]

Adding @haberman as he was able to help with a few other JS issues.

Any chance this could be looked into?

[haberman]

Many of the options we have internally are legacy/deprecated, so we haven't open-sourced them. The ones that we want to keep we will likely want to integrate into descriptor.proto.

Could you say more about how you want to use toObject() and fromObject()? I ask because this format is not standardized, and it is similar to (but not the same as) proto3 JSON.

Also how do you want to use xids?

[hochhaus]

Thanks Joshua. All I need is proto3 JSON support (I was not aware of the different toObject() JSON format). Also I have no current need for xid, I was only trying to be complete.

Could the proto3 JSON support be open sourced?

[haberman]

We don't currently have proto3 JSON support implemented for JavaScript (even internally). Inside Google most JavaScript projects use a wire format called JSPB that is specific to JavaScript and encodes protobufs as arrays indexed by field number like [123, "abc", true]. This format has code-size benefits over binary or proto3 JSON formats (basically it can be parsed with JSON.parse() without the need for any generated parsing code). But the JSPB format isn't very standardized (even inside Google) and changes a lot so we haven't open-sourced it.

For JavaScript we've implemented binary support which works across proto2/proto3 and can interoperate with other implementations. proto3 JSON support would be possible to implement, but we haven't done it yet.

[hochhaus]

@haberman Thanks for the additional context.

For what it is worth, the JSPB format that you mentioned looks very similar to the goog.proto2 PBLite format from closure-library. I've been using this for some time as part of the protoclosure project.

Given that proto3 JSON isn't implemented would it be possible to include the toObject and fromObject JSPB support?

[haberman]

For what it is worth, the JSPB format that you mentioned looks very similar to the goog.proto2 PBLite format from closure-library.

Indeed -- that is an example of a format that is similar but not the same as JSPB. I didn't realize that had been open-sourced.

[pcj]

I was under the impression from https://groups.google.com/d/msg/closure-library-discuss/oRZIfaoFGRQ/0FZpl-RIAgAJ that someone is working on grpc support for javascript that may or may not be supported by closure library goog.net.rpc.*. Any insight on JSON support with those efforts?

[haberman]

@stanley-cheung do you have any insight on @pcj's question?

[stanley-cheung]

I am not sure about the full context here, but yes we are working on a javascript client library that will use JS protobuf and the Closure library to support making RPC calls from browsers to gRPC backend via a gRPC gateway. It is still early in that project so nothing concrete is released yet. The current estimate is late Q3 the earliest, probably Q4.

[pcj]

@stanley-cheung Nice. Keep me posted, I may be interested in helping with that.