AWS IoT's Thing Shadow access w/ Websocket over MQTT and Cognito

awsiot_thing_shadow_core.html

<!--
AWS IoT's Thing Shadow access w/ Websocket over MQTT and Cognito
-->
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<script>
  var thing_name = "patlite0";
  var client; // define MQTT Client for global
  var current_status; // Current status for global
  // Get AWS Credentials from Cognito sample code
  AWS.config.region = 'ap-northeast-1'; // Region
  AWS.config.credentials = new AWS.CognitoIdentityCredentials({
    IdentityPoolId: 'ap-northeast-1:ee820603-6830-4786-be8f-85c286c37b58',
  });
  // Main (Require ES2015 (using Template literal))
  AWS.config.credentials.get(function(err) {
    if (err) { console.warn("Get credential failed", err); return; }

    var onOpen = function() {
      client.subscribe(`$aws/things/${thing_name}/shadow/update/documents`);
      // <Optional> Get actively current status (on startup and interval)
      client.subscribe(`$aws/things/${thing_name}/shadow/get/accepted`, {onSuccess: function() {
        var ping_for_get = new Paho.MQTT.Message("");
        ping_for_get.destinationName = `$aws/things/${thing_name}/shadow/get`;
        var active_sync = function() {
          client.send(ping_for_get);
          setTimeout(active_sync, 60000);
        };
        active_sync();
      }});
    };

    var onMessage = function(message) {
      var obj = JSON.parse(message.payloadString);
      var state = ('current' in obj) ? obj.current : obj; // for normalize. NOTE: When receiving /update/documents there is a 'current' in JSON / ref: http://docs.aws.amazon.com/ja_jp/iot/latest/developerguide/thing-shadow-mqtt.html#update-documents-pub-sub-topic
      console.log(message.destinationName, state);
    };

    var onClose = function(e) { console.log(e); };

    var endpoint = SigV4Utils.getSignedUrl("wss", `data.iot.${AWS.config.region}.amazonaws.com`, "/mqtt", "iotdevicegateway", AWS.config.region, AWS.config.credentials.accessKeyId, AWS.config.credentials.secretAccessKey, AWS.config.credentials.sessionToken);
    var clientId = Math.random().toString(36).substring(7);
    client = new Paho.MQTT.Client(endpoint, clientId);
    client.connect({useSSL: true, timeout: 3, mqttVersion: 4, onSuccess: onOpen, onFailure: onClose});
    client.onMessageArrived = onMessage;
    client.onConnectionLost = onClose;
  });
</script>