### Start rclnodejs Action Server Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/actions/README.md

Starts the basic action server for demonstrating action communication. Ensure ROS 2 is installed and sourced, and navigate to the example directory.

```bash
cd example/actions
node action_server/action-server-example.mjs
```

--------------------------------

### Run Lifecycle Node Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/lifecycle/README.md

Execute the lifecycle node example using Node.js. Ensure you have the necessary dependencies installed.

```bash
node lifecycle-node-example.mjs
```

--------------------------------

### Install and Run Manipulator Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/electron/manipulator/README.md

Installs dependencies and starts the Electron-based manipulator demo. Ensure ROS 2 is sourced before running these commands.

```bash
cd demo/electron/manipulator
source /opt/ros/<distro>/setup.bash   # required before install and launch
npm install
npm start
```

--------------------------------

### Start rclnodejs Action Client Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/actions/README.md

Starts the basic action client to communicate with an action server. This client sends a goal, receives feedback, and processes the final result.

```bash
cd example/actions
node action_client/action-client-example.mjs
```

--------------------------------

### Run ParameterClient Basic Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

This example shows basic usage of the ParameterClient to get and set parameter values. It requires the turtlesim node to be running in a separate terminal.

```bash
ros2 run turtlesim turtlesim_node
```

```bash
cd example/parameter
node parameter-client-basic-example.mjs
```

--------------------------------

### Controlled Startup Sequences with Lifecycle Nodes

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/lifecycle-nodes.md

Implement controlled startup sequences by defining node states like 'configure' and 'activate'. This example shows a camera node initializing hardware and starting capture.

```javascript
onConfigure() {
  // Initialize camera hardware
  // Allocate memory buffers
  // Set up image processing pipeline
}

onActivate() {
  // Start camera capture
  // Begin publishing images
}
```

--------------------------------

### Run Parameter Declaration Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

Execute this script to declare and inspect a parameter. Ensure ROS 2 is installed and sourced, and navigate to the example directory.

```bash
cd example/parameter
node parameter-declaration-example.mjs
```

--------------------------------

### Install and Run ROS 2 Car Control Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/electron/car/README.md

Steps to install dependencies and start the car control demo application. Ensure ROS 2 is sourced before running these commands.

```bash
cd demo/electron/car
source /opt/ros/<distro>/setup.bash   # required before install and launch
npm install
npm start
```

--------------------------------

### Run Publisher Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/README.md

Executes a ROS 2 publisher example. Ensure you are in a cloned repository and have sourced your ROS 2 environment.

```bash
node example/topics/publisher/publisher-example.mjs
```

--------------------------------

### Run Packaged Turtle TF2 Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/electron/turtle_tf2/README.md

Example of how to run the packaged standalone application. ROS 2 must be installed and sourced.

```bash
source /opt/ros/$ROS_DISTRO/setup.bash
./out/rclnodejs-turtle-tf2-demo-linux-x64/rclnodejs-turtle-tf2-demo
```

--------------------------------

### Package Installation

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/rclcpp/CMakeLists.txt

Marks the package for installation.

```cmake
ament_package()
```

--------------------------------

### Run rclnodejs Action Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/actionlib.md

Starts the action server example. Navigate to the rclnodejs directory and execute the provided Node.js script.

```bash
# Terminal 1 - Start the action server
cd /path/to/rclnodejs
node example/actions/action_server/action-server-example.js
```

--------------------------------

### Install Dependencies

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/web/typescript/README.md

Installs the necessary npm packages for the demo.

```bash
cd demo/web/typescript
npm install
```

--------------------------------

### Install and Run Electron Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/electron/topics/README.md

Steps to install dependencies and launch the rclnodejs Electron demo. Ensure ROS 2 is sourced before running.

```bash
cd demo/electron/topics
source /opt/ros/<distro>/setup.bash   # required before launch
npm install
npm start
```

--------------------------------

### Run GetMap Examples with Test Script

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/services/README.md

Executes the GetMap service and client examples using a convenience test script. This script automates the process of starting the service, testing the client, and cleaning up.

```bash
cd /path/to/rclnodejs
./test_getmap_examples.sh
```

--------------------------------

### Start rclnodejs Action Cancellation Client Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/actions/README.md

Starts an action client designed to demonstrate goal cancellation. This client sends a goal, receives feedback for a period, and then cancels the ongoing goal.

```bash
node action_client/action-client-cancel-example.mjs
```

--------------------------------

### ParameterClient Advanced Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

A comprehensive example showcasing all features of ParameterClient, including declaring parameters, describing parameters, getting parameter types, handling timeouts, and request cancellation.

```APIDOC
## ParameterClient Advanced Example

### Description
Provides a comprehensive demonstration of all `ParameterClient` features and capabilities. This includes declaring parameters on a target node and utilizing all client operations such as listing, getting/setting single/multiple parameters, describing parameters, retrieving parameter types, and handling timeouts and request cancellation.

### Run Command
`node parameter-client-advanced-example.mjs`
```

--------------------------------

### Run Built-in Observable Subscription Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/observable-subscriptions.md

Execute the pre-built rclnodejs observable subscription example. This requires running a publisher in a separate terminal.

```bash
# Terminal 1 - Start a publisher
node example/topics/publisher/publisher-example.js

# Terminal 2 - Run the observable subscription example
node example/topics/subscriber/subscription-observable-example.js
```

--------------------------------

### Hardware Driver Initialization

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/lifecycle/README.md

Example of initializing hardware connections in the onConfigure state and starting hardware communication in the onActivate state for a hardware driver lifecycle node.

```javascript
onConfigure() {
  // Initialize hardware connections
  this.initializeHardware();
  return rclnodejs.lifecycle.CallbackReturnCode.SUCCESS;
}

onActivate() {
  // Start hardware communication
  this.startHardwareStreaming();
  return rclnodejs.lifecycle.CallbackReturnCode.SUCCESS;
}
```

--------------------------------

### Run Parameter Declaration Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/parameter-service.md

Execute the parameter declaration example script from the rclnodejs repository.

```bash
cd /path/to/rclnodejs
node example/parameter/parameter-declaration-example.js
```

--------------------------------

### Run Subscriber Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/topics/README.md

Starts the subscriber node to receive ROS 2 messages. This should be run in a separate terminal after the publisher.

```bash
node subscriber/subscription-example.mjs
```

--------------------------------

### Implement Parameter Service Node

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/parameter-service.md

Create a node that starts the parameter service, which is enabled by default but can be explicitly controlled. This example shows declaring multiple parameters with their descriptors.

```javascript
class ParameterServiceNode {
  constructor() {
    // Parameter services are enabled by default
    // You can explicitly control them via NodeOptions
    const NodeOptions = rclnodejs.NodeOptions;
    const options = new NodeOptions();
    options.startParameterServices = true; // default is true

    this.node = rclnodejs.createNode('param_service_node', options);

    // Declare some parameters
    this.declareParameters();

    console.log('Parameter services are running');
  }

  declareParameters() {
    const parameters = [
      new Parameter('device_name', ParameterType.PARAMETER_STRING, 'sensor_1'),
      new Parameter('sample_rate', ParameterType.PARAMETER_DOUBLE, 100.0),
      new Parameter('enable_debug', ParameterType.PARAMETER_BOOL, false),
    ];

    const descriptors = parameters.map(
      (param) =>
        new ParameterDescriptor(
          param.name,
          param.type,
          `Parameter: ${param.name}`
        )
    );

    this.node.declareParameters(parameters, descriptors);
  }

  async run() {
    console.log('Node running with parameter services...');
    rclnodejs.spin(this.node);
  }
}

// Usage
async function main() {
  await rclnodejs.init();
  const paramNode = new ParameterServiceNode();
  await paramNode.run();
}

main().catch(console.error);
```

--------------------------------

### Install Demo Dependencies

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/actions/README.md

Install the demo's npm dependencies, ignoring scripts to use the prebuilt rclnodejs package.

```bash
npm install --ignore-scripts
```

--------------------------------

### Run Parameter Override Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

Run this example to demonstrate overriding a declared parameter's value from the command line. Prerequisites include sourcing ROS 2 and navigating to the example directory.

```bash
cd example/parameter
node parameter-override-example.mjs
```

--------------------------------

### Manage Service and Introspection Resource Cleanup

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/service-introspection.md

This example demonstrates creating a managed service that includes starting the service, configuring introspection, and ensuring proper cleanup by disabling introspection before shutting down. It also handles SIGINT and SIGTERM signals for graceful exit.

```javascript
function createManagedIntrospectionService() {
  let service;
  let node;

  async function start() {
    await rclnodejs.init();
    node = new rclnodejs.Node('managed_service');

    service = node.createService(
      'example_interfaces/srv/AddTwoInts',
      'managed_service',
      handleRequest
    );

    configureIntrospectionSafely(
      service,
      node.getClock(),
      rclnodejs.QoS.profileSystemDefault,
      rclnodejs.ServiceIntrospectionStates.CONTENTS
    );

    rclnodejs.spin(node);
  }

  function stop() {
    if (service) {
      // Disable introspection before cleanup
      try {
        service.configureIntrospection(
          node.getClock(),
          rclnodejs.QoS.profileSystemDefault,
          rclnodejs.ServiceIntrospectionStates.OFF
        );
      } catch (error) {
        console.warn('Failed to disable introspection:', error.message);
      }
    }

    rclnodejs.shutdown();
  }

  function handleRequest(request, response) {
    const result = response.template;
    result.sum = request.a + request.b;
    response.send(result);
  }

  // Handle cleanup on exit
  process.on('SIGINT', stop);
  process.on('SIGTERM', stop);

  return { start, stop };
}
```

--------------------------------

### Install rclnodejs Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/services/README.md

Installs the rclnodejs demo package, linking the local rclnodejs repository. Use --ignore-scripts to prevent native addon rebuilds.

```bash
cd demo/typescript/services
npm install --ignore-scripts
```

--------------------------------

### Run rclnodejs Single Goal Action Server Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/actions/README.md

Runs an action server example configured to handle only a single goal at a time, useful for testing goal abortion behavior when a new goal arrives.

```bash
node action_server/action-server-single-goal-example.mjs
```

--------------------------------

### Run ParameterWatcher Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

This example showcases the ParameterWatcher, allowing you to monitor specific parameters for changes. It requires the turtlesim node to be running and involves setting parameters in a third terminal to observe updates.

```bash
ros2 run turtlesim turtlesim_node
```

```bash
cd example/parameter
node parameter-watcher-example.mjs
```

```bash
ros2 param set /turtlesim background_r 200
ros2 param set /turtlesim background_b 100
ros2 param set /turtlesim background_g 50  # This won't trigger (removed from watch list)
```

--------------------------------

### Run rclnodejs Deferred Execution Action Server Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/actions/README.md

Runs an action server example that implements deferred execution, introducing a 3-second delay before processing goals.

```bash
node action_server/action-server-defer-example.mjs
```

--------------------------------

### Install rclnodejs

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/topics/README.md

Install rclnodejs and its dependencies. Ensure you are in the correct directory.

```bash
cd demo/typescript/topics
npm install
```

--------------------------------

### Start rclnodejs-web Runtime with JSON Configuration

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/web/README.md

Starts the rclnodejs-web runtime by loading its configuration from a specified JSON file. This method is an alternative to using command-line arguments for configuration.

```bash
npx -p rclnodejs rclnodejs-web web.json
```

--------------------------------

### Full Service and Client with Introspection Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/service-introspection.md

This example sets up a service, a client, and a monitor node to demonstrate service introspection. It configures introspection for both the service and client, sends requests, and logs service events. Introspection configuration is conditional based on the ROS 2 distribution.

```javascript
const rclnodejs = require('rclnodejs');

async function runIntrospectionExample() {
  await rclnodejs.init();

  // Create nodes
  const serviceNode = new rclnodejs.Node('introspection_service_node');
  const clientNode = new rclnodejs.Node('introspection_client_node');
  const monitorNode = new rclnodejs.Node('introspection_monitor_node');

  // Create service
  const service = serviceNode.createService(
    'example_interfaces/srv/AddTwoInts',
    'add_two_ints_introspection',
    (request, response) => {
      console.log(`Service processing: ${request.a} + ${request.b}`);
      const result = response.template;
      result.sum = request.a + request.b;
      response.send(result);
    }
  );

  // Create client
  const client = clientNode.createClient(
    'example_interfaces/srv/AddTwoInts',
    'add_two_ints_introspection'
  );

  // Create event monitor subscription
  const eventSubscription = monitorNode.createSubscription(
    'example_interfaces/srv/AddTwoInts_Event',
    '/add_two_ints_introspection/_service_event',
    (eventMsg) => {
      console.log('=== Service Event ===');
      console.log(`Event Type: ${getEventTypeName(eventMsg.info.event_type)}`);
      console.log(
        `Timestamp: ${eventMsg.info.stamp.sec}.${eventMsg.info.stamp.nanosec}`
      );
      console.log(`Sequence: ${eventMsg.info.sequence_number}`);

      if (eventMsg.request && eventMsg.request.length > 0) {
        console.log(
          `Request: a=${eventMsg.request[0].a}, b=${eventMsg.request[0].b}`
        );
      }

      if (eventMsg.response && eventMsg.response.length > 0) {
        console.log(`Response: sum=${eventMsg.response[0].sum}`);
      }

      console.log('====================\n');
    }
  );

  // Configure introspection if supported
  if (
    rclnodejs.DistroUtils.getDistroId() >
    rclnodejs.DistroUtils.getDistroId('humble')
  ) {
    const clock = serviceNode.getClock();
    const qos = rclnodejs.QoS.profileSystemDefault;

    // Configure both service and client introspection
    service.configureIntrospection(
      clock,
      qos,
      rclnodejs.ServiceIntrospectionStates.CONTENTS
    );
    client.configureIntrospection(
      clock,
      qos,
      rclnodejs.ServiceIntrospectionStates.CONTENTS
    );

    console.log('Introspection configured for both service and client');
  } else {
    console.log('Introspection not supported in this ROS 2 version');
  }

  // Wait for service
  if (!(await client.waitForService(5000))) {
    console.error('Service not available');
    return;
  }

  // Start spinning all nodes
  serviceNode.spin();
  clientNode.spin();
  monitorNode.spin();

  // Make multiple service calls
  for (let i = 0; i < 3; i++) {
    const request = {
      a: BigInt(Math.floor(Math.random() * 100)),
      b: BigInt(Math.floor(Math.random() * 100)),
    };

    console.log(`\nSending request ${i + 1}: ${request.a} + ${request.b}`);

    client.sendRequest(request, (response) => {
      console.log(`Received response ${i + 1}: ${response.sum}`);
    });

    // Wait between calls
    await new Promise((resolve) => setTimeout(resolve, 2000));
  }
}

function getEventTypeName(eventType) {
  const eventTypes = {
    0: 'REQUEST_SENT',
    1: 'REQUEST_RECEIVED',
    2: 'RESPONSE_SENT',
    3: 'RESPONSE_RECEIVED',
  };
  return eventTypes[eventType] || `UNKNOWN(${eventType})`;
}

// Run the example
runIntrospectionExample().catch(console.error);
```

--------------------------------

### Run AddTwoInts Service Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/services/README.md

Starts the AddTwoInts service server. This script should be run in a separate terminal before starting the client.

```bash
cd /path/to/rclnodejs
node example/services/service/service-example.mjs
```

--------------------------------

### Start Server and Client Simultaneously

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/actions/README.md

Execute both the action server and client concurrently using npm scripts.

```bash
npm run start:both
```

--------------------------------

### Parameter Declaration Example Output

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/parameter-service.md

Expected output when running the parameter declaration example, showing declared parameter name, type, value, and descriptor.

```bash
Declared parameter: param1
Parameter details:  Parameter {
  name: 'param1',
  type: 4,
  value: 'hello world'
}
ParameterDescriptor {
  name: 'param1',
  type: 4,
  description: '',
  additionalConstraints: '',
  readOnly: false
}
```

--------------------------------

### Install and Run Turtle TF2 Demo

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/electron/turtle_tf2/README.md

Steps to install the demo and run the turtlesim node and the Electron app. Ensure ROS 2 is sourced in the same terminal as npm commands.

```bash
cd demo/electron/turtle_tf2
source /opt/ros/<distro>/setup.bash   # required, in the same terminal as npm install / npm start
npm install
ros2 run turtlesim turtlesim_node        # in another sourced terminal
npm start
```

--------------------------------

### Start rclnodejs-web Runtime with Command Line Arguments

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/web/README.md

Starts the rclnodejs-web runtime using command-line arguments to configure ports and expose ROS 2 services, topics, and actions for browser access. Ensure ROS 2 environment is sourced before execution.

```bash
source /opt/ros/<distro>/setup.bash
npx -p rclnodejs rclnodejs-web \
  --port 9000 --http-port 9001 \
  --call /add_two_ints=example_interfaces/srv/AddTwoInts \
  --publish /chatter=std_msgs/msg/String \
  --subscribe /scan=sensor_msgs/msg/LaserScan
```

--------------------------------

### Start Action Client

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/actions/README.md

Run the TypeScript action client demo in a separate terminal to interact with the server.

```bash
npm run start:client
```

--------------------------------

### Start Action Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/typescript/actions/README.md

Run the TypeScript action server demo in a separate terminal.

```bash
npm run start:server
```

--------------------------------

### Manual Landing Page Rebuild Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tools/jsdoc/README.md

Example script to manually rebuild the `build/gh-pages-docs/docs/index.html` file for a specific published version. It requires setting several environment variables to point to the correct paths for package metadata and documentation roots.

```bash
mkdir -p build/gh-pages-docs/.tmp
git show 1.8.0:package.json > build/gh-pages-docs/.tmp/package-1.8.0.json

export RCLNODEJS_DOCS_ROOT="$PWD/build/gh-pages-docs/docs"
export RCLNODEJS_DOCS_INDEX_PATH="$PWD/build/gh-pages-docs/docs/index.html"
export RCLNODEJS_LOCAL_INDEX_PATH=''
export RCLNODEJS_PACKAGE_JSON_PATH="$PWD/build/gh-pages-docs/.tmp/package-1.8.0.json"

node tools/jsdoc/build-index.js
rm -rf build/gh-pages-docs/.tmp
```

--------------------------------

### Allow-list Rejection Example (curl)

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/web/javascript/index.html

Example using curl to demonstrate an allow-list rejection scenario, resulting in a 404 status and a structured error body.

```bash
curl -sS -X POST http://localhost:9001/capability/call/dangerous \
  -H 'content-type: application/json' -d '{}'
# => {"ok":false,"error":"capability not exposed: call /dangerous","code":"not_exposed"}
```

--------------------------------

### Start ROSocket Server with Pre-declared Types

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/rosocket/README.md

Initialize ROS, start a node, and then launch the ROSocket server on port 9000. Pre-declare topic and service types for client convenience.

```javascript
const rclnodejs = require('rclnodejs');
const { startRosocket } = require('rclnodejs/rosocket');

await rclnodejs.init();
const node = new rclnodejs.Node('rosocket_node');
rclnodejs.spin(node);

await startRosocket({
  node,
  port: 9000,
  // optional: pre-declare types so clients can omit ?type=
  topicTypes:   { '/chatter':       'std_msgs/msg/String' },
  serviceTypes: { '/add_two_ints':  'example_interfaces/srv/AddTwoInts' },
});
```

--------------------------------

### System Orchestration with Lifecycle Node Commands

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/lifecycle-nodes.md

Orchestrate the startup of multiple nodes in a specific order using lifecycle commands. This example configures camera nodes before processing nodes, then activates all.

```bash
# Start all camera nodes first
ros2 lifecycle set /camera_left configure
ros2 lifecycle set /camera_right configure

# Then start processing nodes
ros2 lifecycle set /image_processor configure
ros2 lifecycle set /object_detector configure

# Finally activate everything
ros2 lifecycle set /camera_left activate
ros2 lifecycle set /camera_right activate
ros2 lifecycle set /image_processor activate
ros2 lifecycle set /object_detector activate
```

--------------------------------

### Run ROS Graph Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/graph/README.md

Execute the comprehensive ROS graph introspection example using Node.js. Ensure you have rclnodejs installed and a ROS 2 environment sourced.

```bash
node ros-graph-example.mjs
```

--------------------------------

### Start Static File Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/web/javascript/README.md

Run the static file server in the second shell to host the HTML page and map SDK requests. This makes the SDK importable via a URL.

```bash
node static.mjs
```

--------------------------------

### Node Creation and Service/Client Setup in rclnodejs

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/service-introspection.md

Demonstrates how to create an rclnodejs Node, and then set up a service and a client. It emphasizes the importance of waiting for service availability before proceeding.

```javascript
// Use the constructor pattern (as in tests)
const node = new rclnodejs.Node('node_name');

// Create service and client
const service = node.createService('srv_type', 'service_name', callback);
const client = node.createClient('srv_type', 'service_name');

// Always wait for service availability
if (!(await client.waitForService(1000))) {
  throw new Error('client unable to access service');
}

// Start spinning
node.spin();
```

--------------------------------

### System Management Script for Orchestrating Nodes

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/lifecycle-nodes.md

An example JavaScript script demonstrating how to orchestrate the startup sequence of multiple lifecycle nodes, including configuring and activating them in a defined order.

```javascript
// system-manager.js
const rclnodejs = require('rclnodejs');

class SystemManager {
  constructor() {
    this.nodes = [
      'camera_left',
      'camera_right',
      'image_processor',
      'robot_controller',
    ];
  }

  async init() {
    await rclnodejs.init();
    this.node = rclnodejs.createNode('system_manager');
  }

  async startupSequence() {
    console.log('🚀 Starting system startup sequence...');

    // Phase 1: Configure all nodes
    for (const nodeName of this.nodes) {
      await this.transitionNode(nodeName, 'configure');
    }

    // Phase 2: Activate in specific order
    const activationOrder = [
      'camera_left',
      'camera_right',
      'image_processor',
      'robot_controller',
    ];
    for (const nodeName of activationOrder) {
      await this.transitionNode(nodeName, 'activate');
      await this.sleep(1000); // Wait 1 second between activations
    }

    console.log('✅ System startup complete!');
  }

  async transitionNode(nodeName, transition) {
    // Implementation would call lifecycle service
    console.log(`🔄 ${transition} ${nodeName}`);
  }

  sleep(ms) {
    return new Promise((resolve) => setTimeout(resolve, ms));
  }
}
```

--------------------------------

### Complete Test-Based Example for Type Description Service

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/type-description-service.md

This example showcases the full workflow of using the Type Description Service. It initializes rclnodejs, creates a node and publisher, retrieves publisher information, and then uses a client to request and process the type description for a given topic type. It includes checks for ROS 2 version compatibility and handles service availability and response processing.

```javascript
const rclnodejs = require('rclnodejs');
const TypeDescriptionService = require('rclnodejs/lib/type_description_service');
const DistroUtils = require('rclnodejs/lib/distro');

async function testTypeDescriptionService() {
  // Check if Type Description Service is supported
  if (DistroUtils.getDistroId() < DistroUtils.getDistroId('jazzy')) {
    console.log(
      'Type Description Service is not supported in this ROS 2 version'
    );
    return;
  }

  await rclnodejs.init();

  const nodeName = 'test_type_description_service';
  const node = rclnodejs.createNode(nodeName);
  rclnodejs.spin(node);

  // Create a publisher (this registers the type with the node)
  const topic = 'test_get_type_description_publisher';
  const topicType = 'std_msgs/msg/String';
  node.createPublisher(topicType, topic);

  // Get publisher information to extract type hash
  const infos = node.getPublishersInfoByTopic(
    '/test_get_type_description_publisher',
    false
  );

  if (infos.length === 0) {
    throw new Error('Publisher info not found');
  }

  console.log('Publisher info found:', infos[0]);

  // Create a client to get the type description
  const request = {
    type_name: topicType,
    type_hash: TypeDescriptionService.toTypeHash(infos[0].topic_type_hash),
    include_type_sources: true,
  };

  const serviceName = `/test_type_description_service/get_type_description`;
  const GetTypeDescription = 
    'type_description_interfaces/srv/GetTypeDescription';
  const client = node.createClient(GetTypeDescription, serviceName);

  const result = await client.waitForService(5000);
  if (!result) {
    throw new Error('Service not available');
  }

  // Send request and handle response
  const promise = new Promise((resolve, reject) => {
    const timer = setInterval(() => {
      client.sendRequest(request, (response) => {
        clearInterval(timer);

        console.log('Response received:');
        console.log('- Successful:', response.successful);

        if (response.successful) {
          console.log(
            '- Type name:',
            response.type_description.type_description.type_name
          );
          console.log(
            '- Number of fields:',
            response.type_description.type_description.fields.length
          );
          console.log('- Type sources length:', response.type_sources.length);

          // Print field information
          response.type_description.type_description.fields.forEach(
            (field, index) => {
              console.log(
                `  Field ${index}: ${field.name} (${JSON.stringify(field.type)})`
              );
            }
          );

          // Print source if available
          if (response.type_sources.length > 0) {
            console.log('- Raw file contents:');
            console.log(response.type_sources[0].raw_file_contents);
          }

          resolve(response);
        } else {
          reject(
            new Error(
              `Type description request failed: ${response.failure_reason}`
            )
          );
        }
      });
    }, 2000);
  });

  await promise;
  console.log('Test completed successfully');
  rclnodejs.shutdown();
}

// Run the test
testTypeDescriptionService().catch(console.error);

```

--------------------------------

### Robot Configuration Service Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/ros2-basic-concepts.md

A practical example of a service server managing robot configuration. It provides services to get the current configuration and to set the safety mode.

```javascript
const rclnodejs = require('rclnodejs');

class RobotConfigurationService {
  constructor() {
    this.robotConfig = {
      maxSpeed: 2.0,
      safetyEnabled: true,
      operationMode: 'autonomous',
    };
  }

  async start() {
    await rclnodejs.init();
    this.node = rclnodejs.createNode('robot_config_service');

    // Service to get robot configuration
    this.node.createService(
      'example_interfaces/srv/Trigger',
      'get_robot_config',
      (request, response) => {
        const result = response.template;
        result.success = true;
        result.message = JSON.stringify(this.robotConfig);
        response.send(result);
      }
    );

    // Service to set max speed
    this.node.createService(
      'example_interfaces/srv/SetBool',
      'set_safety_mode',
      (request, response) => {
        this.robotConfig.safetyEnabled = request.data;

        const result = response.template;
        result.success = true;
        result.message = `Safety mode set to: ${request.data}`;
        response.send(result);
      }
    );

    console.log('Robot configuration services ready');
    rclnodejs.spin(this.node);
  }
}

const configService = new RobotConfigurationService();
configService.start().catch(console.error);
```

--------------------------------

### Resource Management with Lifecycle Node States

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/lifecycle-nodes.md

Manage resource consumption by activating expensive operations only when the node is active. This example starts GPU processing on activation and stops it on deactivation.

```javascript
onActivate() {
  // Only start expensive GPU processing when active
  this.startGPUProcessing();
}

onDeactivate() {
  // Free GPU resources when inactive
  this.stopGPUProcessing();
}
```

--------------------------------

### Start WebSocket Gateway (rosocket)

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/README.md

Launches the rosocket WebSocket gateway. This is a thin gateway with zero browser dependencies, suitable for quick prototypes.

```bash
npx rosocket --port 9000 --topic /chatter:std_msgs/msg/String
```

--------------------------------

### Run MessageIntrospector Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/message-introspector/README.md

Execute the message introspection example script.

```bash
node message-introspector-example.mjs
```

--------------------------------

### Navigate to Demo Directory

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/web/javascript/README.md

Change the current directory to the JavaScript demo folder.

```bash
cd demo/web/javascript
```

--------------------------------

### Run ParameterClient Advanced Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

Demonstrates advanced ParameterClient functionality, including listing available parameters and retrieving parameter descriptors. This script should be run after the turtlesim node is active.

```bash
cd example/parameter
node parameter-client-advanced-example.mjs
```

--------------------------------

### Install rclnodejs from npm

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/README.md

Use this command to install rclnodejs as a dependency for your Node.js application. This is the recommended method for most users.

```bash
npm i rclnodejs
```

--------------------------------

### Install rclnodejs Module

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/docs/BUILDING.md

Install the rclnodejs module using npm. This command builds the native addon using node-gyp.

```javascript
npm install
```

--------------------------------

### Run ROS 2 Runtime and Demo Server

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/demo/web/typescript/README.md

Starts the ROS 2 runtime and a local demo server that includes a service and a publisher. This is a convenience script for the demo.

```bash
source /opt/ros/<distro>/setup.bash
npm run server
# rclnodejs/web : ws://localhost:9000/capability
#               also http://localhost:9001/capability
```

--------------------------------

### Parameter Override Example Output

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/parameter-service.md

Expected output when running the parameter override example, indicating the parameter name and its overridden value.

```bash
Declared parameter: param1
Parameter overridden:  Parameter {
  name: 'param1',
  type: 4,
  value: 'hello ros2'
}
```

--------------------------------

### ParameterClient Basic Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/parameter/README.md

Demonstrates basic access and modification of parameters on a remote node using ParameterClient. It covers connecting to a node, listing parameters, and getting/setting individual and multiple parameters.

```APIDOC
## ParameterClient Basic Example

### Description
Demonstrates accessing and modifying parameters on a remote node using `ParameterClient`. This example covers connecting to a target node, listing available parameters, and performing single and batch get/set operations.

### Target Node
`turtlesim` (run: `ros2 run turtlesim turtlesim_node`)

### Run Command
`node parameter-client-basic-example.mjs`
```

--------------------------------

### Start rclnodejs Service for Service Test

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/README.md

Start the rclnodejs service in one terminal for the service test. This should be run before the client benchmark.

```bash
# Terminal 1: Start service (adjust for your language)
node benchmark/rclnodejs/service/service-stress-test.js -s 1024  # Node.js
```

--------------------------------

### Basic CMake Project Setup

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/test/custom_msg_test/CMakeLists.txt

Sets the minimum CMake version and project name. Essential for any CMake project.

```cmake
cmake_minimum_required(VERSION 3.8)
project(custom_msg_test)
```

--------------------------------

### Start C++ Service for Service Test

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/README.md

Start the C++ service in one terminal for the service test. This should be run before the client benchmark.

```bash
# Terminal 1: Start service (adjust for your language)
./service-stress-test -s 1024                              # C++ (from build dir)
```

--------------------------------

### Start Python Service for Service Test

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/README.md

Start the Python service in one terminal for the service test. This should be run before the client benchmark.

```bash
# Terminal 1: Start service (adjust for your language)
python3 service/service-stress-test.py -s 1024             # Python
```

--------------------------------

### Start rclnodejs Subscriber for Topic Test

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/README.md

Start the rclnodejs subscriber in one terminal for the topic test. This should be run before the publisher benchmark.

```bash
# Terminal 1: Start subscriber (adjust for your language)
node benchmark/rclnodejs/topic/subscription-stress-test.js  # Node.js
```

--------------------------------

### Start Python Subscriber for Topic Test

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/benchmark/README.md

Start the Python subscriber in one terminal for the topic test. This should be run before the publisher benchmark.

```bash
# Terminal 1: Start subscriber (adjust for your language)
python3 topic/subscription-stress-test.py          # Python
```

--------------------------------

### Testing and Linting Setup

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/test/custom_msg_test/CMakeLists.txt

Configures testing and linting dependencies if testing is enabled. Includes options to skip copyright and cpplint checks.

```cmake
if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  # the following line skips the linter which checks for copyrights
  # comment the line when a copyright and license is added to all source files
  set(ament_cmake_copyright_FOUND TRUE)
  # the following line skips cpplint (only works in a git repo)
  # comment the line when this package is in a git repo and when
  # a copyright and license is added to all source files
  set(ament_cmake_cpplint_FOUND TRUE)
  ament_lint_auto_find_test_dependencies()
endif()
```

--------------------------------

### Run Error Handling Example

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/example/error-handling/README.md

Execute the main error handling example script for rclnodejs. This script demonstrates all 10 error handling patterns.

```bash
node example/error-handling/error-handling-example.mjs
```

--------------------------------

### Build and Source Custom Message Test Package

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/test/custom_msg_test/README.md

Navigate to the custom message test directory and build the package. Then, source the setup script to make the custom messages available.

```bash
# From the test directory
cd custom_msg_test
colcon build
source install/setup.bash
```

--------------------------------

### Start the Node and Trigger Transitions

Source: https://github.com/robotwebtools/rclnodejs/blob/develop/tutorials/lifecycle-nodes.md

Starts the node's event loop and manually triggers state transitions. This is used to initiate the lifecycle process.

```javascript
// Start spinning the node
rclnodejs.spin(lifecycleNode);

// Trigger state transitions
lifecycleNode.configure();
lifecycleNode.activate();
```