Node.js Client Library

The node.js client is used for simplifying the interaction with the IBM Watson Internet of Things Platform. The following libraries contain instructions and guidance on using the nodejs ibmiotf node to interact with devices and applications within your organizations.

This client library is divided into three parts, Device, ManagedDevice and Application. The Devices section contains information on how devices publish events and handle commands using the nodejs ibmiotf module, ManagedDevice section contains information on how you can manage the device. More information on device management can be found here.. The Applications section contains information on how applications can use the nodejs ibmiotf module to interact with devices.

This library supports to be loaded in node.js and the browser.

Contributing

The client code is in the src folder and the tests are in the test folder. All code is written in JavaScript 6 and automatically transpiled to JavaScript 5 for testing and building the production version of the library.

• clone repo
• npm install -g babel mocha
• npm install

NPM commands

• npm run test - run the tests once
• npm run test:watch - run the tests in watch mode
• npm build - build the client and browser bundles

Usage

Load the library in node.js

var Client = require('ibmiotf');

Note: When this client library is used in the Node.js environment, it will use tcp/tls. But if a user wants to use websockets in Node.js, the user must add a new property enforce-ws in the configuration.

Load the library in browser

Note: From version 0.2.34, the user must build the library using the below command to get the necessary javascript files to use the library in browser.

npm run build

Load the generated javascript file - iotf-client-bundle.js or iotf-client-bundle-min.js from the dist directory to your web application. Check out the sample on how to use the generated library in your web application.

Supported Features

Devices

DeviceClient is device client for the IBM Watson Internet of Things Platform service. You can use this client to connect to the service, publish events from the device and subscribe to commands.

Constructor

The constructor builds the device client instance. It accepts a configuration JSON containing the following:

• org - Your organization ID
• type - The type of your device
• id - The ID of your device
• auth-method - Method of authentication (the only value currently supported is “token”)
• auth-token - API key token (required if auth-method is “token”)
• domain - (Optional)The messaging endpoint URL. By default, the value is "internetofthings.ibmcloud.com"(Watson IoT Production server).
• enforce-ws - (Optional)Enforce Websocket when using the library in Node.js
• use-client-certs - (Optional) Enforces use of client side certificates when specified as true
• server-ca - (Optional) Specifies the custom server certificate signed using device key
• client-ca - (Mandatory when use-client-certs:true) Specifies the path to device-client CA certificate
• client-cert - (Mandatory when use-client-certs:true) Specifies the path to device-client certificate
• client-key - (Mandatory when use-client-certs:true) Specifies the path to device-client key
• client-key-passphrase - (Optional) Specifies the passphrase for the device-client key if exists
• clean-session - (Optional) Sets the clean session flag on the connection. It is used for durable and non-durable subscriptions.

If you want to use quickstart, then enter only the first three properties.

var Client = require("ibmiotf");
var config = {
    "org" : "organization",
    "id" : "deviceId",
    "domain": "internetofthings.ibmcloud.com",
    "type" : "deviceType",
    "auth-method" : "token",
    "auth-token" : "authToken"
};
 
var deviceClient = new Client.IotfDevice(config);
 
....

If you want to use registered mode with Client Side Certificates, you need to have use-client-certs defined to true and client-ca, client-cert and client-key referring to appropriate paths as shown below:

var Client = require("ibmiotf");
var config = {
    "org" : "organization",
    "id" : "deviceId",
    "domain": "internetofthings.ibmcloud.com",
    "type" : "deviceType",
    "auth-method" : "token",
    "auth-token" : "authToken",
    "use-client-certs": [true / false],
    "server-ca": "path to custom server certificate", # Optional, if there is custom server certificate, then can be used
    "client-ca": "path to device-client ca certificate",
    "client-cert": "path to device-client certificate",
    "client-key": "path to device-client key"
};
 
var deviceClient = new Client.IotfDevice(config);
 
....

Connect

Connect to the IBM Watson Internet of Things Platform by calling the connect function

 
deviceClient.connect();
 
deviceClient.on('connect', function () {
 
//Add your code here
});
 
....

After the successful connection to the IoTF service, the device client emits connect event. So all the device logic can be implemented inside this callback function.

The Device Client automatically tries to reconnect when it loses connection. When the reconnection is successful, the client emits reconnect event.

Logging

By default, all the logs of warn are logged. If you want to enable more logs, use the log.setLevel function. Supported log levels - trace, debug, info, warn, error.

 
deviceClient.connect();
//setting the log level to 'trace'
deviceClient.log.setLevel('trace');
deviceClient.on('connect', function () {
 
//Add your code here
});
 
....

Publishing events

Events are the mechanism by which devices publish data to the Internet of Things Platform. The device controls the content of the event and assigns a name for each event it sends.

When an event is received by the IOT Platform the credentials of the connection on which the event was received are used to determine from which device the event was sent. With this architecture it is impossible for a device to impersonate another device.

Events can be published at any of the three quality of service levels defined by the MQTT protocol. By default events will be published as qos level 0.

Events can be published by using

• eventType - Type of event to be published e.g status, gps
• eventFormat - Format of the event e.g json
• data - Payload of the event. Supported formats for data are String, Buffer and JSON
• QoS - qos for the publish event. Supported values : 0,1,2

 
var deviceClient = new Client.IotfDevice(config);
 
deviceClient.connect();
 
deviceClient.on("connect", function () {
    //publishing event using the default quality of service
    deviceClient.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    deviceClient.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
});
 
....

The device events can also be sent using HTTP instead of JSON.

 
var deviceClient = new Client.IotfDevice(config);
 
//setting the log level to trace. By default its 'warn'
deviceClient.log.setLevel('debug');
 
deviceClient.publishHTTPS('myevt', 'json', '{"value": 23 }').then(function onSuccess (argument) {
    console.log("Success");
    console.log(argument);
}, function onError (argument) {
 
    console.log("Fail");
    console.log(argument);
});
....

Handling commands

When the device client connects, it automatically subscribes to any command for this device. To process specific commands you need to register a command callback function. The device client emits command when a command is received. The callback function has the following properties

• commandName - name of the command invoked
• format - e.g json, xml
• payload - payload for the command
• topic - actual topic where the command was received

var deviceClient = new Client.IotfDevice(config);
 
deviceClient.connect();
 
deviceClient.on("connect", function () {
    //publishing event using the default quality of service
    deviceClient.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
});
 
deviceClient.on("command", function (commandName,format,payload,topic) {
    if(commandName === "blink") {
        console.log(blink);
        //function to be performed for this command
        blink(payload);
    } else {
        console.log("Command not supported.. " + commandName);
    }
});
....

Handling errors

When the device clients encounters an error, it emits an error event.

var deviceClient = new Client.IotfDevice(config);
 
deviceClient.connect();
 
deviceClient.on("connect", function () {
    //publishing event using the default quality of service
    deviceClient.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
});
 
deviceClient.on("error", function (err) {
    console.log("Error : "+err);
});
....

Disconnect Client

Disconnects the client and releases the connections

var deviceClient = new Client.IotfDevice(config);
 
deviceClient.connect();
 
client.on("connect", function () {
    //publishing event using the default quality of service
    client.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    client.publish("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
 
    //disconnect the client
    client.disconnect();
});
 
....

Application

ApplicationClient is application client for the Internet of Things Platform service. This section contains information on how applications interact with devices.

Constructor

The constructor builds the application client instance. It accepts an configuration json containing the following :

• org - Your organization ID
• id - The unique ID of your application within your organization.
• auth-key - API key
• auth-token - API key token
• type - use 'shared' to enable shared subscription
• domain - (Optional)The messaging endpoint URL. By default the value is "internetofthings.ibmcloud.com"(Watson IoT Production server).
• enforce-ws - (Optional)Enforce Websocket when using the library in Node.js
• clean-session - (Optional) Sets the clean session flag on the connection. It is used for durable and non-durable subscriptions.
• instance-id - (Optional) Sets the instance Id for the connection. This is used for Mixed-durability shared subscriptions. Use this when the clean-session is set false and type is shared.

If you want to use quickstart, then send only the first two properties.

var Client = require("ibmiotf");
var appClientConfig = {
    "org" : orgId,
    "id" : appId,
    "domain": "internetofthings.ibmcloud.com",
    "auth-key" : apiKey,
    "auth-token" : apiToken
}
 
var appClient = new Client.IotfApplication(appClientConfig);
 
....

Connect

Connect to the IBM Watson Internet of Things Platform by calling the connect function

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
//Add your code here
});
 
....

After the successful connection to the IoTF service, the application client emits connect event. So all the logic can be implemented inside this callback function.

The Application Client automatically tries to reconnect when it loses connection. When the reconnection is successful, the client emits reconnect event.

Logging

By default, all the logs of warn are logged. If you want to enable more logs, use the log.setLevel function. Supported log levels - trace, debug, info, warn, error.

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
//setting the log level to 'trace'
appClient.log.setLevel('trace');
appClient.on("connect", function () {
 
//Add your code here
});
 
....

Shared Subscription

Use this feature to build scalable applications which will load balance messages across multiple instances of the application. To enable this, pass 'type' as 'shared' in the configuration.

var appClientConfig = {
  org: 'xxxxx',
  id: 'myapp',
  "auth-key": 'a-xxxxxx-xxxxxxxxx',
  "auth-token": 'xxxxx!xxxxxxxx',
  "type" : "shared" // make this connection as shared subscription
};
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
//Add your code here
});
 
appClient.on("error", function (err) {
    console.log("Error : "+err);
});
....

For Mixed-durability shared subscriptions, you will also have to set the instance Id to the connection. Following example has this functionality explained

var appClientConfig = {
  org: 'xxxxx',
  id: 'myapp',
  "auth-key": 'a-xxxxxx-xxxxxxxxx',
  "auth-token": 'xxxxx!xxxxxxxx',
  "type" : "shared",
  "instance-id" : "xxxxxxx",
  "clean-session" : false
};
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
//Add your code here
});
 
appClient.on("error", function (err) {
    console.log("Error : "+err);
});
....

Handling errors

When the application clients encounters an error, it emits an error event.

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
//Add your code here
});
 
appClient.on("error", function (err) {
    console.log("Error : "+err);
});
....

Subscribing to device events

Events are the mechanism by which devices publish data to the Internet of Things Platform. The device controls the content of the event and assigns a name for each event it sends.

When an event is received by the IOT Platform the credentials of the connection on which the event was received are used to determine from which device the event was sent. With this architecture it is impossible for a device to impersonate another device.

By default, applications will subscribe to all events from all connected devices. Use the type, id, event and msgFormat parameters to control the scope of the subscription. A single client can support multiple subscriptions. The code samples below give examples of how to subscribe to devices dependent on device type, id, event and msgFormat parameters.

To subscribe to all events from all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents();
});
 
....

To subscribe to all events from all devices of a specific type

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents("mydeviceType");
});
 
....

To subscribe to a specific event from all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents("+","+","myevent");
});
 
....

To subscribe to a specific event from two or more different devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents("myDeviceType","device01","myevent");
    appClient.subscribeToDeviceEvents("myOtherDeviceType","device02","myevent");
});
 
....

To subscribe to all events published by a device in json format

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents("myDeviceType","device01","+","json");
 
});
 
....

Handling events from devices

To process the events received by your subscriptions you need to implement an device event callback method. The ibmiotf application client emits the event deviceEvent. This function has the following properties

• deviceType
• deviceId
• eventType
• format
• payload - Device event payload
• topic - Original topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceEvents("myDeviceType","device01","+","json");
 
});
appClient.on("deviceEvent", function (deviceType, deviceId, eventType, format, payload) {
 
    console.log("Device Event from :: "+deviceType+" : "+deviceId+" of event "+eventType+" with payload : "+payload);
 
});
 
....

Subscribing to device state events

Device State Events are a feature of the Data Management capabilities of the Watson IoT platform. They provide a mechanism for applications to be notifified when the state of a Digital Twin is updated. For more information on these concepts, including a detailed walk-through, please refer to the Data Management section of the Watson IoT platform documentation.

By default, applications will subscribe to all state events from all Logical Interfaces, on all devices, of all types. Use the type, id, and interfaceId parameters to control the scope of the subscription. A single client can support multiple subscriptions. The code samples below give examples of how to subscribe to device state events.

To subscribe to all state events from all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateEvents();
});
 
....

To subscribe to all state events from all devices of a specific type

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateEvents("mydeviceType");
});
 
....

To subscribe to state events from a specific Logical Interface from all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateEvents("+","+","5846cd7c6522050001db0e0d");
});
 
....

To subscribe to all state events from two or more different devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateEvents("myDeviceType","device01","+");
    appClient.subscribeToDeviceStateEvents("myOtherDeviceType","device02","+");
});
 
....

Handling device state events

To process the state events received by your subscriptions you need to implement an device state event callback method. The ibmiotf application client emits the event deviceState. This function has the following properties

• deviceType
• deviceId
• interfaceId
• payload - Device state event payload
• topic - Original topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateEvents();
});
 
appClient.on("deviceState", function (deviceType, deviceId, interfaceId, payload) {
    console.log("Device State Event from :: "+deviceType+" : "+deviceId+" for interface "+interfaceId+" with payload : "+payload);
});
 
....

Subscribing to device state error events

Device State Error Events are a published when there are validation failures, or runtime errors while computing device state. Examples of this include cases where a Device event does not conform to the schema for that Event Type in the Device Twin configuration, or where the generated Device State does not conform to the schema for the Logical Interface. For more information on these concepts, including a detailed walk-through, please refer to the Data Management section of the Watson IoT platform documentation.

By default, applications will subscribe to all state error events from all devices, of all types. Use the type, and id, parameters to control the scope of the subscription. A single client can support multiple subscriptions. The code samples below give examples of how to subscribe to device state error events.

To subscribe to all state error events from all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateErrorEvents();
});
 
....

To subscribe to all state error events from all devices of a specific type

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateErrorEvents("mydeviceType");
});
 
....

To subscribe to state events from a specific device

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateErrorEvents("mydeviceType","device01");
});
 
....

To subscribe to all state events from two or more different devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateErrorEvents("myDeviceType","device01","+");
    appClient.subscribeToDeviceStateErrorEvents("myOtherDeviceType","device02","+");
});
 
....

Handling device state error events

To process the state error events received by your subscriptions you need to implement an device state error event callback method. The ibmiotf application client emits the event deviceStateError. This function has the following properties

• deviceType
• deviceId
• payload - state error event payload
• topic - Original topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToDeviceStateErrorEvents();
});
 
appClient.on("deviceStateError", function (deviceType, deviceId, payload) {
    console.log("Device State Error Event from :: "+deviceType+" : "+deviceId+" with payload : "+payload);
});
 
....

Subscribing to rule trigger events

Rule trigger events are published when a Logical Interface Rule expression evaluates to true. These rules are evaluated during the processing of device events that can contribute to Device State.

By default, applications will subscribe to all rule trigger events for all Logical Interfaces and all Rules. Use the interfaceId, and ruleId, parameters to control the scope of the subscription. A single client can support multiple subscriptions. The code samples below give examples of how to subscribe to rule trigger events.

To subscribe to all rule trigger events for all logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleTriggerEvents();
});
 
....

To subscribe to all rule trigger events for a specific logical interface

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleTriggerEvents("5846cd7c6522050001db0e0d");
});
 
....

To subscribe to all rule trigger events for a specific rule on all logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleTriggerEvents("+","3548c2846d21045501fd1d10");
});
 
....

To subscribe to specific rule trigger events from two or more different logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleTriggerEvents("5846cd7c6522050001db0e0d","3548c2846d21045501fd1d10");
    appClient.subscribeToRuleTriggerEvents("5847d1df6522050001db0e1a","3548c2846d21045501fd1d10");
});
 
....

Handling rule trigger events

To process the rule trigger events received by your subscriptions you need to implement an rule trigger event callback method. The ibmiotf application client emits the event ruleTrigger. This function has the following properties

• interfaceId
• ruleId
• payload - rule trigger event payload
• topic - Original topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleTriggerEvents();
});
 
appClient.on("ruleTrigger", function(interfaceId, ruleId, payload) {
    console.log("Rule Trigger Event on interface : "+interfaceId+" for rule: "+ruleId+" with payload : "+payload);
});
 
....

Subscribing to rule error events

Rule error events are published when a Logical Interface Rule expression evaluation results in an error. These rules are evaluated during the processing of device events that can contribute to Device State.

By default, applications will subscribe to all rule error events for all Logical Interfaces and all Rules. Use the interfaceId, and ruleId, parameters to control the scope of the subscription. A single client can support multiple subscriptions. The code samples below give examples of how to subscribe to rule error events.

To subscribe to all rule error events for all logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleErrorEvents();
});
 
....

To subscribe to all rule error events for a specific logical interface

 
var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleErrorEvents("5846cd7c6522050001db0e0d");
});
 
....

To subscribe to all rule error events for a specific rule on all logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleErrorEvents("+","3548c2846d21045501fd1d10");
});
 
....

To subscribe to specific rule error events from two or more different logical interfaces

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleErrorEvents("5846cd7c6522050001db0e0d","3548c2846d21045501fd1d10");
    appClient.subscribeToRuleErrorEvents("5847d1df6522050001db0e1a","3548c2846d21045501fd1d10");
});
 
....

Handling rule error events

To process the rule error events received by your subscriptions you need to implement an rule error event callback method. The ibmiotf application client emits the event ruleError. This function has the following properties

• interfaceId
• ruleId
• payload - rule error event payload
• topic - Original topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
    appClient.subscribeToRuleErrorEvents();
});
 
appClient.on("ruleError", function(interfaceId, ruleId, payload) {
    console.log("Rule Error Event on interface : "+interfaceId+" for rule: "+ruleId+" with payload : "+payload);
});
 
....

Subscribing to device status

By default, this will subscribe to status updates for all connected devices. Use the type and id parameters to control the scope of the subscription. A single client can support multiple subscriptions.

Subscribe to status updates for all devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceStatus();
 
});

Subscribe to status updates for all devices of a specific type

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceStatus("myDeviceType");
 
});

Subscribe to status updates for two different devices

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceStatus("myDeviceType","device01");
    appClient.subscribeToDeviceStatus("myOtherDeviceType","device02");
 
});

Handling status updates from devices

To process the status updates received by your subscriptions you need to implement an device status callback method. The ibmiotf application client emits the event deviceStatus. This function has the following properties

• deviceType
• deviceId
• payload - Device status payload
• topic

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    appClient.subscribeToDeviceStatus("myDeviceType","device01");
    appClient.subscribeToDeviceStatus("myOtherDeviceType","device02");
 
});
appClient.on("deviceStatus", function (deviceType, deviceId, payload, topic) {
 
    console.log("Device status from :: "+deviceType+" : "+deviceId+" with payload : "+payload);
 
});

Publishing events from devices

Applications can publish events as if they originated from a Device. The function requires

• DeviceType
• Device ID
• Event Type
• Format
• Data

Supported formats for data are String, Buffer and JSON

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    var myData={'name' : 'foo', 'cpu' : 60, 'mem' : 50};
    myData = JSON.stringify(myData);
    appClient.publishDeviceEvent("myDeviceType","device01", "myEvent", "json", myData);
 
});

Publishing events from devices(via HTTP)

Applications can publish events as if they originated from a Device. This method uses HTTP instead of MQTT to send messages

• DeviceType
• Device ID
• Event Type
• Format
• Data

Supported formats for data are text, JSON and XML. The 'Content-Type' will be set as application/json or application/xml

var appClient = new Client.IotfApplication(appClientConfig);
 
    appClient.publishHTTPS("raspi", "pi01", "eventType", "json", { d : { 'temp' : 32}}). then (function onSuccess (argument) {
        console.log("Success");
        console.log(argument);
    }, function onError (argument) {
 
        console.log("Fail");
        console.log(argument);
    });
 

Publishing commands to devices

Applications can publish commands to connected devices. The function requires

• DeviceType
• Device ID
• Command Type
• Format
• Data

Supported formats for data are String, Buffer and JSON

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    var myData={'DelaySeconds' : 10};
    myData = JSON.stringify(myData);
    appClient.publishDeviceCommand("myDeviceType","device01", "reboot", "json", myData);
 
});

Disconnect Client

Disconnects the client and releases the connections

var appClient = new Client.IotfApplication(appClientConfig);
 
appClient.connect();
 
appClient.on("connect", function () {
 
    var myData={'DelaySeconds' : 10}
    appClient.publishDeviceCommand("myDeviceType","device01", "reboot", "json", myData);
 
    appClient.disconnect();
});

Gateways

GatewayClient is Gateway client for the IBM Watson Internet of Things Platform service. You can use this client to connect to the platform, publish gateway events, publish device events on behalf of the devices, subscribe to both gateway and device commands.

Constructor

The constructor builds the Gateway client instance. It accepts an configuration json containing the following :

• org - Your organization ID
• type - The type of your gateway
• id - The ID of your gateway
• auth-method - Method of authentication (the only value currently supported is “token”)
• auth-token - API key token (required if auth-method is “token”)
• domain - (Optional)The messaging endpoint URL. By default the value is "internetofthings.ibmcloud.com"(Watson IoT Production server).
• enforce-ws - (Optional)Enforce Websocket when using the library in Node.js
• use-client-certs - (Optional) Enforces use of client side certificates when specified as true
• server-ca - (Optional) Specifies the custom server certificate signed using gateway key
• client-ca - (Mandatory when use-client-certs:true) Specifies the path to gateway-client CA certificate
• client-cert - (Mandatory when use-client-certs:true) Specifies the path to gateway-client certificate
• client-key - (Mandatory when use-client-certs:true) Specifies the path to gateway-client key
• client-key-passphrase - (Optional) Specifies the passphrase for the gateway-client key if exists

var Client = require("ibmiotf");
var config = {
    "org" : "organization",
    "type" : "gatewayType",
    "id" : "gatewayId",
    "domain": "internetofthings.ibmcloud.com",
    "auth-method" : "token",
    "auth-token" : "authToken",
    "use-client-certs": [true / false],
    "server-ca": "path to custom server certificate", # Optional, if there is custom server certificate, then can be used
    "client-ca": "path to gateway-client ca certificate",
    "client-cert": "path to gateway-client certificate",
    "client-key": "path to gateway-client key"
};
 
var gatewayClient = new iotf.IotfGateway(config);
 
....

Connect

Connect to the IBM Watson Internet of Things Platform by calling the connect function

 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
 
//Add your code here
});
 
....

After the successful connection to the platform, the gateway client emits connect event. So all the programming logic can be implemented inside this callback function.

The Gateway Client automatically tries to reconnect when it loses connection. When the reconnection is successful, the client emits reconnect event.

Logging

By default, all the logs of warn are logged. If you want to enable more logs, use the log.setLevel function. Supported log levels - trace, debug, info, warn, error.

 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function() {
 
//Add your code here
});
 
....

Publishing events

Events are the mechanism by which devices publish data to the IBM Watson Internet of Things Platform. The gateway controls the content of the event and assigns a name for each event it sends.

Events can be published at any of the three quality of service levels defined by the MQTT protocol. By default events will be published as qos level 0.

Events can be published by using

• eventType - Type of event to be published e.g status, gps
• eventFormat - Format of the event e.g json
• data - Payload of the event. Supported formats for data are String, Buffer and JSON
• QoS - qos for the publish event. Supported values : 0,1,2

A gateway can publish events from itself and on behalf of any device connected via the gateway.

Publish Gateway Events

 
var gatewayClient = new iotf.IotfGateway(config);
 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
    //publishing gateway events using the default quality of service
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
});
 
....

Publish Device Events

The Gateway can publish the device events on behalf of the device that is connected to the Gateway. Function publishDeviceEvent needs device Type and the Device Id to publish the device events.

 
var gatewayClient = new iotf.IotfGateway(config);
 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
    //publishing device events with deviceType 'Raspi' and deviceId 'pi01' using the default quality of service
    gatewayClient.publishDeviceEvent("Raspi","pi01", "status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    gatewayClient.publishDeviceEvent("Raspi","pi01","status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
});
 
....

Handling commands

Commands are the mechanism by which applications can communicate with devices. Only applications can send commands, which must be issued to specific devices.

The Gateways can receive gateway commands as well as Device commands on behalf of the device. Function subscribeToGatewayCommand is to be used to subscribe to a Gateway command and subscribeToDeviceCommand is to be used to subscribe to a Device command for the device connected to the gateway. To unsubscribe to commands, you can use the functions unsubscribeToGatewayCommand and unsubscribeToDeviceCommand.

To process specific commands you need to register a command callback function. The device client emits command when a command is eceived. The callback function has the following properties

• type - type of the Gateway/Device.
• id - id of the Gateway/Device.
• commandName - name of the command invoked
• format - e.g json, xml
• payload - payload for the command
• topic - actual topic where the command was received

var gatewayClient = new iotf.IotfGateway(config);
 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
 
    //subscribe to command "blink" for the device with Type 'raspi' and id 'pi2'
    gatewayClient.subscribeToDeviceCommand('raspi','pi2','blink');
 
    //subscribe to all commands for the device with Type 'raspi' and id 'pi3'
    gatewayClient.subscribeToDeviceCommand('raspi','pi3');
 
    //subscribe to command 'blink' for this gateway.
    gatewayClient.subscribeToGatewayCommand('blink');
 
    //unsubscribe command function
    gatewayClient.unsubscribeToGatewayCommand('blink');
    gatewayClient.unsubscribeToDeviceCommand('raspi','pi2','blink');
});
 
gatewayClient.on('command', function(type, id, commandName, commandFormat, payload, topic){
    console.log("Command received");
    console.log("Type: %s  ID: %s  \nCommand Name : %s Format: %s",type, id, commandName, commandFormat);
    console.log("Payload : %s",payload);
});
....

Handling errors

When the device clients encounters an error, it emits an error event.

var gatewayClient = new iotf.IotfGateway(config);
 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
    //publishing gateway events using the default quality of service
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
});
 
gatewayClient.on("error", function (err) {
    console.log("Error : "+err);
});
....

Disconnect Client

Disconnects the client and releases the connections

var gatewayClient = new iotf.IotfGateway(config);
 
//setting the log level to trace. By default its 'warn'
gatewayClient.log.setLevel('debug');
 
gatewayClient.connect();
 
gatewayClient.on('connect', function(){
    //publishing gateway events using the default quality of service
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}');
 
    //publishing event using the user-defined quality of service
    var myQosLevel=2
    gatewayClient.publishGatewayEvent("status","json",'{"d" : { "cpu" : 60, "mem" : 50 }}', myQosLevel);
 
    //disconnect the client
    gatewayClient.disconnect();
});
 
....

APIs

The API documentation can be found here.