@foxglove/rosmsg

ROS1 and ROS2 message definition parser

Introduction

The Robot Operating System (ROS) defines a simplified message description language for describing data types. This library parses those message definitions and can round trip them back into a canonical string format suitable for checksum generation. The parsed definitions are useful for serialization or deserialization when paired with other libraries.

This library supports both ROS1, ROS 2, and the ROS 2 IDL subsetmessage definitions.

Usage

import { parse, parseRos2idl, stringify } from "@foxglove/rosmsg";

const definitionStr = `# geometry_msgs/msg/Pose
geometry_msgs/msg/Point position
geometry_msgs/msg/Quaternion orientation

===
MSG: geometry_msgs/msg/Point
float64 x
float64 y
float64 z

===
MSG: geometry_msgs/msg/Quaternion
float64 x
float64 y
float64 z
float64 w`;

const messageDefinition = parse(definitionStr);
const messageDefinition = parse(definitionStr, {ros2: true}); // for ROS 2 definitions

// stringify(messageDefinition) will return a canonical string, similar to
// _definitionStr_

// ROS2IDL equivalent example
const ros2idlDefinitionStr = `
================================================================================
IDL: geometry_msgs/msg/Pose

module geometry_msgs {
  module msg {
    struct Pose {
      geometry_msgs::msg::Point position;
      geometry_msgs::msg::Quaternion orientation;
    };
  };
};

================================================================================
IDL: geometry_msgs/msg/Point

module geometry_msgs {
  module msg {
    struct Point {
      double x;
      double y;
      double z;
    };
  };
};

================================================================================
IDL: geometry_msgs/msg/Quaternion

module geometry_msgs {
  module msg {
    struct Quaternion {
      double x;
      double y;
      double z;
      double w;
    };
  };
};
`;

const messageDefinition = parseRos2idl(ros2idlDefinitionStr);

// print the parsed message definition structure
console.log(JSON.stringify(messageDefinition, null, 2));

Prints:

[
  {
    "definitions": [
      {
        "type": "geometry_msgs/msg/Point",
        "isArray": false,
        "name": "position",
        "isComplex": true
      },
      {
        "type": "geometry_msgs/msg/Quaternion",
        "isArray": false,
        "name": "orientation",
        "isComplex": true
      }
    ]
  },
  {
    "name": "geometry_msgs/msg/Point",
    "definitions": [
      {
        "type": "float64",
        "isArray": false,
        "name": "x",
        "isComplex": false
      },
      {
        "type": "float64",
        "isArray": false,
        "name": "y",
        "isComplex": false
      },
      {
        "type": "float64",
        "isArray": false,
        "name": "z",
        "isComplex": false
      }
    ]
  },
  {
    "name": "geometry_msgs/msg/Quaternion",
    "definitions": [
      {
        "type": "float64",
        "isArray": false,
        "name": "x",
        "isComplex": false
      },
      {
        "type": "float64",
        "isArray": false,
        "name": "y",
        "isComplex": false
      },
      {
        "type": "float64",
        "isArray": false,
        "name": "z",
        "isComplex": false
      },
      {
        "type": "float64",
        "isArray": false,
        "name": "w",
        "isComplex": false
      }
    ]
  }
]

License

@foxglove/rosmsg is licensed under the MIT License.

Releasing

1. Run yarn version --[major|minor|patch] to bump version
2. Run git push && git push --tags to push new tag
3. GitHub Actions will take care of the rest

Stay in touch

Join our Slack channel to ask questions, share feedback, and stay up to date on what our team is working on.