Events

Overview

The events interface consists of three parts:

• The event API resource returns URIs and URI templates to collections of events, so that all events or events of a specified type and/or a specific source device can be retrieved.
• The event collection resource retrieves events and enables creating new events.
• The event resource represents individual events that can be queried and deleted.

Note that for all PUT/POST requests accept header should be provided, otherwise an empty response body will be returned.

Events API

EventAPI [application/vnd.com.nsn.cumulocity.eventApi+json]

GET - Event API resource

Response body: application/vnd.com.nsn.cumulocity.inventoryApi+json

Required role: ROLE_EVENT_READ

Example request - Get the event API resource

200 - OK

GET <<url>>/event

Example response

HTTP/1.1
200 - OK

{
"self" : "<<Event API URL>>",
"events" : {
	"self" :"<<EventCollection URL>>"
},
"eventsForType" : "<<EventCollection URL>>?type={type}",
"eventsForSource" : "<<EventCollection URL>>?source={source}",
"eventsForTime" : "<<EventCollection URL>>?dateFrom={dateFrom}&dateTo={dateTo}",
"eventsForFragmentType" : "<<EventCollection URL>>?fragmentType={fragmentType}",
"eventsForSourceAndType" : "<<EventCollection URL>>?type={type}&source={source}",
"eventsForSourceAndTime" : "<<EventCollection URL>>?source={source}&dateFrom={dateFrom}&dateTo={dateTo}",
"eventsForSourceAndFragmentType" : "<<EventCollection URL>>?source={source}&fragmentType={fragmentType}",
"eventsForDateAndFragmentType" : "<<EventCollection URL>>?dateFrom={dateFrom}&dateTo={dateTo}&fragmentType={fragmentType}",
"eventsForFragmentTypeAndType" : "<<EventCollection URL>>?fragmentType={fragmentType}&type={type}",
"eventsForTimeAndType" : "<<EventCollection URL>>?dateFrom={dateFrom}&dateTo={dateTo}&type={type}",
"eventsForSourceAndDateAndFragmentType" : "<<EventCollection URL>>?source={source}&dateFrom={dateFrom}&dateTo={dateTo}&fragmentType={fragmentType}",
"eventsForSourceAndDateAndFragmentTypeAndType" : "<<EventCollection URL>>?source={source}&dateFrom={dateFrom}&dateTo={dateTo}&fragmentType={fragmentType}&type={type}",
"eventsForSourceAndFragmentTypeAndType" : "<<EventCollection URL>>?source={source}&fragmentType={fragmentType}&type={type}",
"eventsForSourceAndTimeAndType" : "<<EventCollection URL>>?source={source}&dateFrom={dateFrom}&dateTo={dateTo}&type={type}",
"eventsForDateAndFragmentTypeAndType" : "<<EventCollection URL>>?dateFrom={dateFrom}&dateTo={dateTo}&fragmentType={fragmentType}&type={type}"
}

Event collection

EventCollection [application/vnd.com.nsn.cumulocity.eventCollection+json]

GET - Event collection

Response body: application/vnd.com.nsn.cumulocity.eventcollection+json

Required role: ROLE_EVENT_READ

Example request - Retrieve information about an event collection

200-OK

GET <<url>>/event/events

Example response

HTTP/1.1
200 - OK

{
 "self":"...",
 "events":[
   {
     "id" : "10",
     "self" : "...",
     "creationTime" : "2011-09-06T12:03:27.927+02:00",
     "type" : "com_cumulocity_model_DoorSensorEvent",
     "time" : "2011-09-06T12:03:27.845+02:00",
     "text" : "Door sensor was triggered.",
     "com_othercompany_Extension" : { ... },
     "source":{
		"name": "...",
		"self": "...",
		"id":"12345"}
   },
   {
     "id":"11",
     ...
   }
 ],
 "statistics" : {
    "totalPages" : 2,
    "pageSize" : 5,
    "currentPage : 1
 }
}

POST - Create a new event

Request body: application/vnd.com.nsn.cumulocity.event+json;ver=…

Response body: application/vnd.com.nsn.cumulocity.event+json

Required role: ROLE_EVENT_ADMIN or owner of source object

Example request - Create a new event

POST /event/events
Host: <URL>

{
  "time" : "2011-09-06T12:03:27.845+02:00",
  "type" : "com_cumulocity_model_DoorSensorEvent",
  "text" : "Door sensor was triggered.",
  "source": {
	"id" : "12345"
  }
}

Example response

HTTP/1.1
201 - Created

{
  "id" : "10",
  "self" : "<<URL of new event>>",
  "time" : "2011-09-06T12:03:27.845+02:00",
  "creationTime" : "2011-09-06T12:03:27.927+02:00",
  "type" : "com_cumulocity_model_DoorSensorEvent",
  "text" : "Door sensor was triggered.",
  "source" : {
	"id":"12345",
	"self": "...",
	"name": "..."
  }
}

For POST requests, the source parameter is required to have only an id.

The id and creationTime of the new event are generated by the server and returned in the response to the POST operation.

In case of executing range queries on events API, like query by dateFrom and dateTo, the latest events are returned first. It is possible to change the order by adding query parameter “revert=true” to the request URL. In many use cases it is needed to get the oldest event sent from the device. This can be accomplished by passing “revert” param together with “dateFrom” and “dateTo” params to sort the outcome by date, e.g. pass dateFrom from a year ago, and dateTo from the feature.

PUT - Update an event

Request body: application/vnd.com.nsn.cumulocity.event+json

Response body: application/vnd.com.nsn.cumulocity.event+json

Required role: ROLE_EVENT_ADMIN or owner of source object

Example Request - Change the text of an event

    PUT <<url>>/event/events/<<eventId>>

    {
      "text": "Life full of events"
    }

Example response

HTTP/1.1
200 - OK

{
  "creationTime": "2016-11-08T16:07:40.917+01:00",
  "time": "2014-03-03T12:03:27.845Z",
  "id": "10",
  "self": ".../event/events/<<eventId>>",
  "source": {
    "id": "12345",
    "self": ".../inventory/managedObjects/<<objectId>>"
  },
  "text": "Life full of events",
  "type": "TestAlarm"
}

DELETE - Delete an event collection

The DELETE method allows for deletion of event collections. Applicable query parameters are equivalent to GET method.

Request body: N/A

Response body: N/A

Required role: ROLE_EVENT_ADMIN

Example request

     DELETE: <<url>>/event/events....

Example response

HTTP/1.1
204 - NO CONTENT

Info: DELETE requests are not synchronous. The response could be returned before the delete request has been completed. This may happen especially when the deleted event has a lot of associated data. After sending the request, the platform starts deleting the associated data in an asynchronous way. Finally, the requested event is deleted after all associated data has been deleted.

Event

Event [application/vnd.com.nsn.cumulocity.event+json]

GET - Representation of an event

Response body: application/vnd.com.nsn.cumulocity.event+json

Required role: ROLE_EVENT_READ

Example request - Retrieve information about an event

GET <<url>>/event/events/<<eventID>>    

Example response

HTTP/1.1
200 OK

{
  "id" : "10",
  "self" : "...",
  "time" : "2011-09-06T12:03:27.845+02:00",
  "creationTime" : "2011-09-06T12:03:27.927+02:00",
  "type" : "com_cumulocity_model_DoorSensorEvent",
  "text" : "Door sensor was triggered.",
  "source" : {
 	"id":"12345",
	"self ": "..."
  }
}

DELETE - Delete an event

Request Body: N/A.

Response Message Body: N/A.

Required role: ROLE_EVENT_ADMIN or owner of source object.

Example Request - Delete an event

DELETE <<url>>/event/events/<<eventID>>

Example Response

HTTP/1.1
204 NO CONTENT

Info: DELETE requests are not synchronous. The response could be returned before the delete request has been completed. This may happen especially when the deleted event has a lot of associated data. After sending the request, the platform starts deleting the associated data in an asynchronous way. Finally, the requested event is deleted after all associated data has been deleted.

Notifications

With the event notification API it is possible to receive updates for all events for a specific device. The basic protocol for receiving notifications is described in the Section “Real-time notifications”. The URL is

/cep/realtime

The subscription channel needs to contain the managed object ID of the device or a “*” as placeholder to receive notifications for the events of all devices

/events/<<deviceId>>

The response will additionally to the event object contain a “realtimeAction” to identify which action resulted in the given object (CREATE, UPDATE or DELETE). In case of a deletion the data will only contain the ID of the deleted event.

Required role: ROLE_EVENT_READ

Example Response:

HTTP/1.1
200 - OK
[
  {
    "channel": "/events/12345",
    "successful": true,
    "error": "",
    "data": [{
      "realtimeAction": "CREATE",
      "data": {
        "id": "1",
        "self": "...",
        "source": {
          "12345"
        },
        "creationTime": "2011-09-06T12:03:27.927+02:00",
        "text": "event has been triggered"
      }
    }],
    "clientId": "Un1q31d3nt1f13r"
  }
]

Binaries

The events Rest API has the possibility to store/retrieve and delete binaries for events.

Every event can have one binary attached.

GET - Download a binary

Required role: ROLE_EVENT_READ

Example request

    GET <<url>>/event/events/<<eventId>>/binaries

Example response

Response when binary exists:

HTTP/1.1
200 OK

<<content-body>>

Response when binary doesn’t exists or is only partially uploaded or when event doesn’t exist:

HTTP/1.1 
404 OK

<<error-message>>

POST - Upload a binary

Using POST method it is possible to upload binary file as attachment to Event. Size of attachment cannot exceed 50MB.

Required role: ROLE_EVENT_ADMIN

Example request

POST <<url>>/event/events/<<eventId>>/binaries

Example response

Successful response:

HTTP/1.1 
201 Created

{
  "self”: “<<url>>/event/events/<<eventId>>/binaries”,
  “type”: “<<content-type>>”,
  “source”: <<eventId>>,
  “length”: <<content-lenght>>
}

Response when event doesn’t exist:

HTTP/1.1 
404 NOT FOUND
    
<<error-message>>

Response when binary already exists:

HTTP/1.1 
409 CONFLICT

<<error-message>>

Corresponding event will have fragment:

{
  ...
  “c8y_IsBinary”:  {
    “type”: “<<content-type>>”
  }
  ...
}

POST multipart/form-data - Upload a binary

Uploading functionality is also available using multipart request.

Required role: ROLE_EVENT_ADMIN

Example request

POST <<url>>/event/events/<<eventId>>/binaries
    
--myBoundary
Content-Type: application/octet-stream
Content-Disposition: form-data; name="file.txt"

<<content-body>>
--myBoundary--

Successful response:

HTTP/1.1 
201 Created

{
  "self”: “<<url>>/event/events/<<eventId>>/binaries”,
  “type”: “application/octet-stream”,
  “name”: “file.txt”,
  “source”: <<eventId>>,
  "length": <<lenght>>
}

POST content-range - Upload a binary

Files can be uploaded in many chunks using “Content-Range” header.

“Content-Range” header is in format “start-stop/length” where:

• “start” represents beginning of uploaded file, starting from 0,
• “stop” is end of file inclusive,
• “length” is length of whole document, the property is mandatory only in last chunk of file, in other cases it can be replaced with ‘*’

Ie having document with size 10 we can create chunks: “0-3/*”, “4-5/*”, “6-9/10”.

Size of single chunk cannot exceed 5MB.

Required role: ROLE_EVENT_ADMIN

Example first chunk request

POST <<url>>/event/events/<<eventId>>/binaries

<<content-body>>

Example response for first chunk

HTTP/1.1
200 OK

{
"self”: “<<url>>/event/events/<<eventId>>/binaries”,
“type”: “<<content-type>>”,
“range”: “0-399/*”,
“source”: <<eventId>>
}

Corresponding event will have fragment:

{
  ...
  “c8y_IsIncompleteBinary”: {
    “range”: “0-399/*”
  }
  ...
}

Example last request

POST <<url>>/event/events/<<eventId>>/binaries

Example response for last chunk

HTTP/1.1 
201 Created

{
  "self”: “<<url>>/event/events/<<eventId>>/binaries”,
  “type”: “<<content-type>>”,
  “source”: <<eventId>>,
  “length”: <<content-lenght>>
}

PUT - Replace existing binary

Required role: ROLE_EVENT_ADMIN

Example request

PUT <<url>>/event/events/<<eventId>>/binaries

<<content-body>>

Successful response

HTTP/1.1 
201 Created

{
  "self”: “<<url>>/event/events/<<eventId>>/binaries”,
  “type”: “<<content-type>>”,
  “source”: <<eventId>>,
  “length”: <<content-lenght>>
}

DELETE - Delete a binary

Required role: ROLE_EVENT_ADMIN

Example request

DELETE <<url>>/event/events/<<eventId>>/binaries
Authorization: Basic <<auth>>

Example response

Request Body: N/A.

Response Message Body: N/A.

Example response when binary exists:

HTTP/1.1 
204 NO CONTENT

Example response when binary or event doesn’t exist:

HTTP/1.1
404 NOT FOUND

<<error-message>>