@lichtblick/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 and ROS 2 message definitions.

ROS 1 Definition Usage

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

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

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

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

const messageDefinition = parse(definitionStr);

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

Prints:

[
  {
    "definitions": [
      {
        "type": "geometry_msgs/Point",
        "isArray": false,
        "name": "position",
        "isComplex": true
      },
      {
        "type": "geometry_msgs/Quaternion",
        "isArray": false,
        "name": "orientation",
        "isComplex": true
      }
    ]
  },
  {
    "name": "geometry_msgs/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/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
      }
    ]
  }
]

ROS 2 Definition Usage

import { parse, stringify } from "@lichtblick/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, {ros2: true});

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

ROS 2 IDL Support

See (@lichtblick/ros2idl-parser)[https://github.com/lichtblick-suite/omgidl/packages/ros2idl-parser] for our implementation of ros2idl schema support.

License

@lichtblick/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