ROS Client Module (rosClient.ts)

Module path: web_rviz/src/ros/rosClient.ts

Purpose

Wraps roslib connection lifecycle, topic creation, and rosapi service calls used by the ROS info panels and ROS graph snapshots.

Core types

• ConnectionState: disconnected | connecting | connected | error

• TopicInfo: topic name/type pair.

• ServiceInfo: service name/type pair.

• MessageTypeDef: message field metadata.

• MessageDetailsResponse: message details response.

• ServiceDetailsResponse: request/response details response.

• NodeDetails: publishing topics, subscribing topics, and services exposed by a ROS node.

RosClient

onStateChange(listener)

Registers connection state listeners.

getState() / isConnected()

Returns the current state and connection readiness.

connect(url: string): Promise<void>

Creates a ROS WebSocket connection and handles connection, error, and close events.

disconnect(): void

Closes the connection and resets client state.

createTopic(name, messageType, throttleRateMs = 0)

Creates a ROSLIB.Topic for subscription/publication.

listTopicsWithTypes()

Fetches topics with type info via /rosapi/topics and /rosapi/topic_type.

listServicesWithTypes()

Fetches services with type info via /rosapi/services and /rosapi/service_type.

listParams()

Reads parameter names via /rosapi/get_param_names.

listNodes()

Reads node names via /rosapi/nodes. Used by the ROS Graph snapshot builder.

getNodeDetails(node)

Loads publishing, subscribing, and service lists for a node via /rosapi/node_details.

getParam(name)

Loads a parameter value string via /rosapi/get_param.

getMessageDetails(type)

Loads message type definitions via /rosapi/message_details.

getServiceDetails(type)

Loads request/response details in parallel, with compatibility fallback for type vs service key differences.