Azure IoT Device: Type error in client.js

Question

I try to get an ARM device connected to Azure IoT Hub. I chose Node.js and got some sample code to get the device connected. I added the required NPM packages such as azure_iot_device, azure_iot_common, azure_iot_http_base.

Within the code, there is one line of code which causes an error.

The line: client.sendEvent(message, printResultFor('send'));

After this, on the debugging console I get the message:

\NodejsWebApp1\node_modules\azure-iot-device\lib\client.js:596

return new Client(new transportCtor(authenticationProvider), null, new blob_upload_1.BlobUploadClient(authenticationProvider)); ^

TypeError: transportCtor is not a function at Function.Client.fromConnectionString

(C:\Users\InterestedGuy\source\repos\NodejsWebApp1\NodejsWebApp1\node_modules\azure-iot-device\lib\client.js:596:27) at sendmsg (C:\Users\InterestedGuy\source\repos\NodejsWebApp1\NodejsWebApp1\server.js:123:32) at Server. (C:\Users\InterestedGuy\source\repos\NodejsWebApp1\NodejsWebApp1\server.js:48:9) at emitTwo (events.js:87:13) at Server.emit (events.js:172:7) at HTTPParser.parserOnIncoming [as onIncoming] (_http_server.js:529:12) at HTTPParser.parserOnHeadersComplete (_http_common.js:88:23)

Press any key to continue...

First guess was that I miss a library so I simply searched the Web where transportCtor should have been defined - but no success.

So the easy question is: where should this function be defined? I would expect the function is part of the Azure IoT SDK but I could not find it. Since the module client.js from azure_iot_device is reporting the error I expect it somewhere within the SDK - but where?

THX for any advice

Michael Xu - MSFT Michael Xu - MSFT · Accepted Answer · 2018-05-24T05:19:00

You should install azure-iot-device-http package to communicate with Azure IoT Hub from any device over HTTP 1.1. You can use this command to get the latest version.

npm install -g azure-iot-device-http@latest

Following code is a tutorial shows how to use this package.

var clientFromConnectionString = require('azure-iot-device-http').clientFromConnectionString;
var Message = require('azure-iot-device').Message;

var connectionString = '[IoT Hub device connection string]';

var client = clientFromConnectionString(connectionString);

var connectCallback = function (err) {
  if (err) {
    console.error('Could not connect: ' + err);
  } else {
    console.log('Client connected');
    var message = new Message('some data from my device');
    client.sendEvent(message, function (err) {
      if (err) console.log(err.toString());
    });

    client.on('message', function (msg) { 
      console.log(msg); 
      client.complete(msg, function () {
        console.log('completed');
      });
    }); 
  }
};

client.open(connectCallback);

BTW,for this tutorial you also need to install azure-iot-device package.

Azure IoT Device: Type error in client.js

1 Answers