ros2_awesome

ROS 2 awesome

Schema Support for ROS 2 Launch Files

ros2_awesome provides schema definitions for ROS 2 launch files in both YAML and XML formats. These schemas enable:

• Validation
• Auto-completion
• Hover documentation
• Error checking

in editors such as VS Code.

📌 Available Schemas

YAML Schema

https://ok-tmhr.github.io/ros2_awesome/schema/launch.yaml

XML Schema

https://ok-tmhr.github.io/ros2_awesome/schema/launch_ros.xsd

1. Using the Schema in YAML Launch Files

You can explicitly specify the schema at the top of your .launch.yaml file:

# yaml-language-server: $schema=https://ok-tmhr.github.io/ros2_awesome/schema/launch.yaml

launch:
  - arg:
      name: example

This method is portable and works in any environment. See the sample/ directory for complete examples.

2. Using the Schema in XML Launch Files

Add the schema reference inside the <launch> tag:

<launch
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:noNamespaceSchemaLocation="https://ok-tmhr.github.io/ros2_awesome/schema/launch_ros.xsd">

  <arg name="example"/>
</launch>

3. VS Code: Associate the Schema Automatically

If you prefer not to write $schema in every YAML file, VS Code can automatically apply the schema based on file patterns.

Open Settings (JSON) and add:

{
  "yaml.schemas": {
    "https://ok-tmhr.github.io/ros2_awesome/schema/launch.yaml": [
      "*.launch.yaml",
      "*.launch.yml"
    ]
  }
}

Now all launch YAML files will automatically use the schema.

4. VS Code Snippets for Launch Substitutions

This repository includes a snippet extension:

launch_substitution.json

It provides auto-completion for ROS 2 substitution syntax:

$(var name)
$(env FOO)
$(not value)
$(eval ...)

Substitution in Parameter Files

ROS 2 substitutions are not limited to launch files. They also work inside parameter YAML files when loaded through a launch file.

Install as a local VS Code extension

1. Clone this repository
2. Open command pallet (ctrl + shift + p)
3. Run Developer: Install Extension from Location…
4. Choose repository’s directory

VS Code treats snippet JSON files as installable local extensions.

Features

• Typing $ triggers substitution snippets
• Typing not triggers $(not …)
• Works in both YAML and XML launch files
• Fully customizable

5. Sample Files

The sample/ directory contains:

• YAML launch examples using $schema
• XML launch examples using XSD

These samples are the quickest way to understand how the schema behaves.

6. Project Goals

• Provide a strict, complete, and editor-friendly schema for ROS 2 launch files
• Improve developer experience with auto-completion and error detection
• Offer snippets for common substitution patterns
• Maintain compatibility with VS Code and other YAML/XML tooling

7. Contributions

Issues and PRs are welcome. Schema improvements, missing elements, or substitution patterns can be added incrementally.

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