Dart

Duplicate Python websockets

See more WebSocket Examples

Demonstrates how to duplicate the following Python client-side websocket snippet:

async with websockets.connect('ws://192.168.1.35/websocket') as websocket:
await websocket.send("http.controller_login:username=xxx&password=xxxxx")
response = await websocket.recv()

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // In Python, the following line of code does more than just connect:
  // 
  //      websockets.connect('ws://192.168.1.35/websocket')
  // 
  // It is connecting to 192.168.1.35 without using TLS.  If the URI starts with "wss://", then TLS should be used.
  // But this URI begins with just "ws:/", so no TLS.

  // Also, after connecting, a GET request is sent to the /websocket endpoint.
  // In summary, the websockets.connect function is establishing the connection and it sends a GET request.

  // First establish the connection.
  // No TLS, use the default HTTP port 80.
  final rest = CkRest();
  try {
    rest.connect('192.168.1.35', 80, false, false);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final ws = CkWebSocket();

  // Tell the WebSocket to use this connection.
  try {
    ws.useConnection(rest);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Add the standard WebSocket open handshake headers that will be needed.
  // (This adds the required HTTP request headers to the rest object.)
  ws.addClientHeaders();

  // Now send the GET request to /websockets.
  final String responseBody;
  try {
    responseBody = rest.fullRequestNoBody('GET', '/websockets');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // If successful, the HTTP response status code should be 101,
  // and the response body will be empty. (If it failed, we'll have a look
  // at the response body..)
  final statusCode = rest.responseStatusCode;
  print('Response status code: $statusCode');

  if (statusCode != 101) {
    print(responseBody);
    print('-- Failed because of unexpected response status code.');
    return;
  }

  // We have the expected 101 response, so let's now validate the 
  // contents of the response.
  try {
    ws.validateServerHandshake();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('WebSocket connection successful.');

  // The application may now begin sending and receiving frames on the WebSocket connection.

  // The 1st frame sent by the Python snippet is:
  // 
  //     websocket.send("http.controller_login:username=xxx&password=xxxxx")
  // 

  // Send the same using Chilkat, and get the response.
  final finalFrame = true;
  try {
    ws.sendFrame('http.controller_login:username=xxx&password=xxxxx', finalFrame);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Read an incoming frame.
  try {
    ws.readFrame();
  } on ChilkatException catch (e) {
    print('Failed to receive a frame');
    print('ReadFrame fail reason = ${ws.readFrameFailReason}');
    print(e.lastErrorText);
    return;
  }

  // Show the string that was received.
  final receivedStr = ws.getFrameData();
  print('Received: $receivedStr');

  // Continue with whatever additional communications are desired...
  // ....
  // 
}