Subscribing to Service Data of the IoT Platform

Typical Scenario

An NA can subscribe to service data of a device on the IoT platform. When the service data changes (for example, the device is registered, the device reports data or the device status changes), the IoT platform can push change notifications to the NA.

API Function

This API is used by an NA to subscribe to service change notifications on the IoT platform. When the device status or data changes, the IoT platform pushes notifications to the NA.

API Prototype

Method	POST
URL	https://server:port/iocm/app/sub/v1.2.0/subscriptions?ownerFlag={ownerFlag}
Transport Protocol	HTTPS

Request Parameters

Parameter	Mandatory or Optional	Type	Location	Description
app_key	Mandatory	String	header	Identifies an application that can be accessed on the IoT platform. The value of this parameter is allocated by the IoT platform when the application is created on the platform.
Authorization	Mandatory	String	header	Indicates the authentication information for accessing the IoT platform. The value is Bearer {accessToken}, in which {accessToken} indicates the access token returned by the Authentication API.
ownerFlag	Optional	String(256)	query	Indicates the owner flag of the callback URL. false: The callback URL owner is an authorizing application. true: The callback URL owner is an authorized application.
appId	Optional	String(256)	body	Identifies an application that can be accessed on the IoT platform. The value of this parameter is allocated by the IoT platform when the application is created on the platform. Set this parameter to the value of appId of the authorized application.
notifyType	Mandatory	String	body	Indicates the notification type based on which an NA can receive notifications pushed by the IoT platform. deviceAdded: device addition; sending such a notification after subscription bindDevice: device binding; sending such a notification after subscription deviceInfoChanged: device information change; sending such a notification after subscription deviceDataChanged: device data change; sending such a notification after subscription deviceDatasChanged: batch device data change; sending such a notification after subscription deviceCapabilitiesChanged: device service capability change; sending such a notification after subscription deviceCapabilitiesAdded: device service capability added; sending such a notification after subscription deviceCapabilitiesDeleted: device service capability deleted; sending such a notification after subscription deviceDeleted: device deletion; sending such a notification after subscription messageConfirm: message confirmation; sending such a notification after subscription (This function applies only to devices that use the MQTT protocol for access.) commandRsp: command response; sending such a notification after subscription. (This function applies only to devices that use the MQTT protocol for access.) ruleEvent: rule event; sending such a notification after subscription deviceDesiredPropertiesModifyStatusChanged: device shadow modification status change; sending such a notification after subscription
callbackUrl	Mandatory	String(1024)	body	Indicates the callback URL of a subscription, which is used to receive notification messages of the corresponding type. HTTPS or HTTP callback URL can be used. HTTPS is recommended. The callback URL can be a combination of an IP address or a domain name and a port number. An example value is https://XXX.XXX.XXX.XXX:443/callbackurltest.
channel	Optional	String(32)	Body	Indicates the transmission channel. For the MQTT client, the value is MQTT. In other cases, the value is HTTP.

Response Parameters

Status Code: 201 Created

Parameter	Type	Description
subscriptionId	String	Uniquely identifies a subscription. The value of this parameter is allocated by the IoT platform during subscription creation.
notifyType	String	Indicates the notification type.
callbackUrl	String	Indicates the callback URL of the subscription.
clientIds	List<String>	Identifies an MQTT client. The value is that returned when MQTT is subscribed to.

Request Example

Method: POST
request: https://server:port/iocm/app/sub/v1.2.0/subscriptions
Header:
app_key: ******
Authorization: Bearer *****
Content-Type: application/json
Body:
{
  "appId": "*******",
  "notifyType": "deviceInfoChanged",
  "callbackUrl": "https://***********"
}

Response Example

Response:
Status Code: 201 Created
Content-Type: application/json
Body:
{
  "subscriptionId": "*******",
  "notifyType": "*******",
  "callbackUrl": "https://***********"
}

Error Codes

HTTP Status Code	Error Code	Error Description	Remarks
400	100222	The request callbackurl is illegal.	The callback URL is invalid. Recommended handling: Check whether the callback URL in the request body is correct.
403	100217	The application hasn't been authorized.	The application has not been authorized. Recommended handling: In scenarios where applications are not authorized, ensure that request parameter appId is null.
403	1010009	app throttle exceed.	The NA calls the API at a frequency that exceeds the flow control threshold (100 calls per minute by default). Recommended handling: Contact IoT platform maintenance personnel to adjust the flow control threshold or control the API call frequency.
403	1010005	App_key or access_token is invalid.	The access token is invalid. Recommended handling: Check whether accessToken carried in the API request is correct.
409	100227	The resource is conflicted.	A resource conflict occurs. The notification type has been subscribed to. Recommended handling: Check whether the notification type has been subscribed.