protoc-gen-doc

This is a documentation generator plugin for the Google Protocol Buffers compiler (protoc). The plugin can generate HTML, JSON, DocBook and Markdown documentation from comments in your .proto files.

It supports proto2 and proto3, and can handle having both in the same context (see examples for proof).

NOTE: This is a fork of https://github.com/pseudomuto/protoc-gen-doc

Installation

Run: go get -u github.com/kaspanet/protoc-gen-doc/cmd/protoc-gen-doc

Invoking the Plugin

The plugin is invoked by passing the --doc_out, and --doc_opt options to the protoc compiler. The option has the following format:

--doc_opt=<FORMAT>|<TEMPLATE_FILENAME>,<OUT_FILENAME>

The format may be one of the built-in ones ( docbook, html, markdown or json) or the name of a file containing a custom Go template.

Simple Usage

For example, to generate HTML documentation for all .proto files in the proto directory into doc/index.html, type:

protoc --doc_out=./doc --doc_opt=html,index.html proto/*.proto

The plugin executable must be in PATH for this to work.

Using a precompiled binary

Alternatively, you can specify a pre-built/not in PATH binary using the --plugin option.

protoc \
  --plugin=protoc-gen-doc=./protoc-gen-doc \
  --doc_out=./doc \
  --doc_opt=html,index.html \
  proto/*.proto

With a Custom Template

If you'd like to use your own template, simply use the path to the template file rather than the type.

protoc --doc_out=./doc --doc_opt=/path/to/template.tmpl,index.txt proto/*.proto

For information about the available template arguments and functions, see Custom Templates. If you just want to customize the look of the HTML output, put your CSS in stylesheet.css next to the output file and it will be picked up.

Writing Documentation

Messages, Fields, Services (and their methods), Enums (and their values), Extensions, and Files can be documented. Generally speaking, comments come in 2 forms: leading and trailing.

Leading comments

Leading comments can be used everywhere.

/**
 * This is a leading comment for a message
*/
message SomeMessage {
  // this is another leading comment
  string value = 1;
}

NOTE: File level comments should be leading comments on the syntax directive.

Trailing comments

Fields, Service Methods, Enum Values and Extensions support trailing comments.

enum MyEnum {
  DEFAULT = 0; // the default value
  OTHER   = 1; // the other value
}

Excluding comments

If you want to have some comment in your proto files, but don't want them to be part of the docs, you can simply prefix the comment with @exclude.

Example: include only the comment for the id field

/**
 * @exclude
 * This comment won't be rendered
 */
message ExcludedMessage {
  string id   = 1; // the id of this message.
  string name = 2; // @exclude the name of this message

  /* @exclude the value of this message. */
  int32 value = 3;
}

Check out the example protos to see all the options.

Output Example

With the input .proto files

• Booking.proto
• Customer.proto
• Vehicle.proto

the plugin gives the output

• Markdown
• HTML
• DocBook
• JSON

Check out the examples task in the Makefile to see how these were generated.