4.4. High-level HTTP and WebSocket wrappers

The DASHV_BOOST module provides high-level daScript wrapper classes for the low-level dashv C++ bindings.

HvWebServer wraps the WebSocket/HTTP server with convenient route registration (GET, POST, PUT, DELETE, PATCH, HEAD, ANY), static file serving, and WebSocket event callbacks.

HvWebSocketClient wraps the WebSocket client with onOpen, onClose, and onMessage callbacks.

All functions and symbols are in “dashv_boost” module, use require to get access to it.

require dashv/dashv_boost

See also:

4.4.1. Classes

HvWebSocketClient

WebSocket client with event-driven callbacks. Subclass and override onOpen, onClose, and onMessage to handle connection lifecycle and incoming messages. Call process_event_que periodically to dispatch events. Called when the WebSocket connection is established. Called when the WebSocket connection is closed.

Fields:

  • client : WebSocketClient? - Called when a text message is received from the server.

HvWebSocketClient.init(url: string): int

Connects to the given WebSocket URL. Returns 0 on success.

Arguments:

  • url : string

HvWebSocketClient.is_connected(): bool

Returns true if the WebSocket connection is currently open.

HvWebSocketClient.process_event_que()

Processes pending WebSocket events; must be called periodically.

HvWebSocketClient.send(text: string)

Sends a text message to the server.

Arguments:

  • text : string

HvWebSocketClient.close(): int

Closes the WebSocket connection. Returns 0 on success.

HvWebServer

HTTP and WebSocket server with route registration and event callbacks. Subclass and override onWsOpen, onWsClose, onWsMessage, onTick, and onInit as needed. Register HTTP routes with GET, POST, PUT, DELETE, PATCH, HEAD, or ANY. Called when a WebSocket client connects. Override to handle new connections. Called when a WebSocket client disconnects. Override to handle disconnections. Called when a WebSocket message is received. Override to handle messages. Called each tick cycle. Override for periodic work.

Fields:

  • server : WebSocketServer? - Called during server initialization, after the low-level server is created. Override to register routes.

HvWebServer.init(port: int)

Initializes an HTTP/WebSocket server on the specified port.

Arguments:

  • port : int

HvWebServer.init_wss(port: int; httpsPort: int; pathToCert: string = "")

Initializes an HTTPS/WSS server with TLS. Uses the default modules/dasHV/cert directory if pathToCert is empty.

Arguments:

  • port : int

  • httpsPort : int

  • pathToCert : string

HvWebServer.start(): int

Starts the server. Returns 0 on success.

HvWebServer.stop(): int

Stops the server. Returns 0 on success.

HvWebServer.tick()

Processes pending HTTP and WebSocket events; must be called periodically.

HvWebServer.onWsOpen(channel: WebSocketChannel?; url: string#)

def onWsOpen : function<(var self:dashv_boost::HvWebServer;channel:dashv::WebSocketChannel? const;url:string const#):void>

Arguments:
HvWebServer.onWsClose(channel: WebSocketChannel?)

def onWsClose : function<(var self:dashv_boost::HvWebServer;channel:dashv::WebSocketChannel? const):void>

Arguments:
HvWebServer.onWsMessage(channel: WebSocketChannel?; msg: string#)

def onWsMessage : function<(var self:dashv_boost::HvWebServer;channel:dashv::WebSocketChannel? const;msg:string const#):void>

Arguments:
HvWebServer.onTick()

def onTick : function<(var self:dashv_boost::HvWebServer):void>

HvWebServer.onInit()

def onInit : function<(var self:dashv_boost::HvWebServer):void>

HvWebServer.GET(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP GET requests matching uri.

Arguments:
HvWebServer.POST(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP POST requests matching uri.

Arguments:
HvWebServer.PUT(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP PUT requests matching uri.

Arguments:
HvWebServer.DELETE(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP DELETE requests matching uri.

Arguments:
HvWebServer.PATCH(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP PATCH requests matching uri.

Arguments:
HvWebServer.HEAD(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for HTTP HEAD requests matching uri.

Arguments:
HvWebServer.ANY(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers a handler for any HTTP method matching uri.

Arguments:
HvWebServer.STATIC(path: string; dir: string)

Serves static files from dir under the URL prefix path.

Arguments:

  • path : string

  • dir : string

HvWebServer.allow_cors()

Enables cross-origin resource sharing (CORS) on the server.

HvWebServer.set_document_root(dir: string)

Sets the document root directory for static file serving.

Arguments:

  • dir : string

HvWebServer.set_home_page(filename: string)

Sets the default home page file (e.g., index.html).

Arguments:

  • filename : string

HvWebServer.set_index_of(dir: string)

Enables directory listing for the specified directory.

Arguments:

  • dir : string

HvWebServer.set_error_page(filename: string)

Sets a custom error page file.

Arguments:

  • filename : string

HvWebServer.SSE(uri: string; lmb: lambda<(var req:HttpRequest?;var resp:HttpResponse?):http_status>)

Registers an SSE (Server-Sent Events) handler for uri. Same signature as GET/POST — set SSE headers and write events to the response. Uses ANY method matching so any HTTP method reaches this handler.

Arguments:

4.4.2. HTTP request helpers

get_body_bytes(resp: HttpResponse?): array<uint8>

Extracts the response body as an array<uint8>. Returns an empty array if the response is null, non-OK, or has no content.

Arguments:
with_http_request(blk: block<(var req:HttpRequest?#):void>)

Creates a temporary HttpRequest, invokes the block, then cleans up. Use this to configure and send outbound HTTP requests.

Arguments: