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]

Name	Type	Occurs	Description
self	URL	1	Link to this resource.
events	EventCollection	1	Collection of all events.
eventsForType	EventCollection URI template	1	Read-only collection of all events of a particular type (placeholder {type}).
eventsForSource	EventCollection URI template	1	Read-only collection of all events from a particular source object (placeholder {source}).
eventsForSourceAndType	EventCollection URI template	1	Read-only collection of all events of a particular type and from a particular source (placeholders {type} and {source}).
eventsForTime	EventCollection URI template	1	Read-only collection of all events from a particular period (placeholder {dateFrom}, {dateTo}).
eventsForFragmentType	EventCollection URI template	1	Read-only collection of all events containing a particular fragment type (placeholder {fragmentType}).
eventsForSourceAndTime	EventCollection URI template	1	Read-only collection of all events from a particular source object from a particular period (placeholders {source}, {dateFrom}, {dateTo}).
eventsForSourceAndFragmentType	EventCollection URI template	1	Read-only collection of all events of a particular source object containing a particular fragment type (placeholders {source}, {fragmentType}).
eventsForDateAndFragmentType	EventCollection URI template	1	Read-only collection of all events from a particular period containing a particular fragment type (placeholders {dateFrom}, {dateTo}, {fragmentType}).
eventsForFragmentTypeAndType	EventCollection URI template	1	Read-only collection of all events of a particular type containing a particular fragment type (placeholders {fragmentType}, {type}).
eventsForTimeAndType	EventCollection URI template	1	Read-only collection of all events with a particular type from a particular period (placeholders {type}, {dateFrom}, {dateTo}).
eventsForSourceAnd DateAndFragmentType	EventCollection URI template	1	Read-only collection of all events from a particular source object, containing a particular fragment type, from a particular period (placeholders {source}, {dateFrom}, {dateTo}, {fragmentType}).
eventsForSourceAnd DateAndFragmentTypeAndType	EventCollection URI template	1	Read-only collection of all events from a particular source object, with a particular type, containing a particular fragment type, from a particular period (placeholders {source}, {dateFrom}, {dateTo}, {fragmentType}, {type}).
eventsForSourceAnd FragmentTypeAndType	EventCollection URI template	1	Read-only collection of all events from a particular source object, with a particular type, containing a particular fragment type (placeholders {source}, {fragmentType}, {type}).
eventsForSourceAndTimeAndType	EventCollection URI template	1	Read-only collection of all events from a particular source object, with a particular type, from a particular period (placeholders {source}, {type}, {dateFrom}, {dateTo}).
eventsForDateAnd FragmentTypeAndType	EventCollection URI template	1	Read-only collection of all events from a particular type, containing a particular fragment type, from a particular period (placeholders {type}, {dateFrom}, {dateTo}, {fragmentType}).

GET the Event API resource

Response body: Event Api

Required role: ROLE_EVENT_READ

Example request: Retrieve information about Event API Resource

GET /event
 Host: [hostname]
 Authorization: Basic xxxxxxxxxxxxxxxxxxx
 Accept: application/vnd.com.nsn.cumulocity.eventApi+json;ver=0.9

Example response:

HTTP/1.1 200 OK
Content-Type: application/vnd.com.nsn.cumulocity.eventApi+json;ver=...
Content-Length: ...
{
  "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]

Name	Type	Occurs	Description
self	URI	1	Link to this resource.
events	Event	0..n	List of events, see below.
statistics	PagingStatistics	1	Information about paging statistics.
prev	URI	0..1	Link to a potential previous page of events.
next	URI	0..1	Link to a potential next page of events.

GET an event collection

Response body: Event Collection

Required role: ROLE_EVENT_READ

Example request: Retrieve information about an Event Collection

GET /event/events
 Host: [hostname]
 Authorization: Basic xxxxxxxxxxxxxxxxxxx
 Accept: application/vnd.com.nsn.cumulocity.eventCollection+json;ver=0.9

Example response:

HTTP/1.1 200 OK
Content-Type: application/vnd.com.nsn.cumulocity.eventCollection+json;ver=...
Content-Length: ...

{
 "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":{ "id":"12345", "self": "..." }
   }, {
     "id":"11",
     ...
   }
 ],
 "statistics" : {
    "totalPages" : 2,
    "pageSize" : 5,
    "currentPage : 1
 }
}

POST - create a new event

Request body: Event

Response body: Event

Required role: ROLE_EVENT_ADMIN or owner of source object

Example request: Create a new Event

POST /event/events
Host: ...
Authorization: Basic ...
Content-Length: ...
Content-Type: application/vnd.com.nsn.cumulocity.event+json;ver=...

{
  "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
Content-Type: application/vnd.com.nsn.cumulocity.event+json;ver=...
Content-Length: ...
Location: <<URL of new event>>

{
  "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 ": "..." }
}

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 measurement 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 a event

Request body: Event

Response body: Event

Required role: ROLE_EVENT_ADMIN or owner of source object

Example Request: Change the text of a event

PUT /event/events/<<eventId>>
Host: ...
Authorization: Basic ...
Accept: application/vnd.com.nsn.cumulocity.event+json;ver=...
Content-Type: application/vnd.com.nsn.cumulocity.event+json;ver=...
Content-Length: ...
{
  "text": "Life full of events"
}

Example response:

HTTP/1.1 200 OK
Content-Type: application/vnd.com.nsn.cumulocity.event+json;ver=...
{
  "creationTime": "2016-11-08T16:07:40.917+01:00",
  "time": "2014-03-03T12:03:27.845Z",
  "id": "10400",
  "self": ".../event/events/10400",
  "source": {
    "id": "10216",
    "self": ".../inventory/managedObjects/10216"
  },
  "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: /event/events....
 Host: ...
 Authorization: Basic ...

Example response:

HTTP/1.1  204 NO CONTENT

Event

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

Name	Type	Occurs	Description	PUT/POST
id	String	1	Uniquely identifies an event.	No
self	URI	1	Link to this resource.	No
creationTime	String	1	Time when event was created in the database.	No
type	String	1	Identifies the type of this event.	POST: Mandatory PUT: No
time	String	1	Time of the event.	POST: Mandatory PUT: No
text	String	1	Text description of the event.	POST: Mandatory PUT: Optional
source	ManagedObject	1	The ManagedObject that the event originated from, as object containing properties “id”, “self”, “name”, and “type”.	POST: Mandatory PUT: No
*	Object	0..n	Additional properties of the event.	POST: Optional PUT: Optional

GET a representation of an Event

Response body: Event

Required role: ROLE_EVENT_READ

Example request: Retrieve information about an Event

GET /event/events/<<eventID>>
 Host: [hostname]
 Authorization: Basic xxxxxxxxxxxxxxxxxxx
 Accept: application/vnd.com.nsn.cumulocity.event+json;ver=0.9

Example response:

HTTP/1.1 200 OK
Content-Type: application/vnd.com.nsn.cumulocity.event+json;ver=...
Content-Length: ...

{
  "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 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 /event/events/<<eventID>>
 Host: [hostname]
 Authorization: Basic xxxxxxxxxxxxxxxxxxx

Example Response:

HTTP/1.1  204 NO CONTENT

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.

Example Response:

HTTP/1.1 200 OK
Content-Type: application/json
[
  {
    "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"
  }
]

Required role: ROLE_EVENT_READ

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
Authorization: Basic <<auth>>

Example response when binary exists:

HTTP/1.1 200 OK
Content-Type: <<content-type>>
Content-Disposition: attachment; filename=”file.txt”
<<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
Content-Type: <<content-type>>
Content-Length: <<content-lenght>>
Authorization: Basic <<auth>>
<<content-body>>

Successful response:

HTTP/1.1 201 Created
Location: <<url>>/event/events/<<eventId>>/binaries
Content-Type: application/vnd.com.nsn.cumulocity.event+json
{
  "self”: “<<url>>/event/binaries/<<eventId>>”,
  “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
Content-Type: multipart/form-data; boundary=--myBoundary
Authorization: Basic <<auth>>

--myBoundary
Content-Type: application/octet-stream
Content-Disposition: form-data; name="file.txt"

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

Successful response:

HTTP/1.1 201 Created
Location: <<url>>/event/events/<<eventId>>/binaries
Content-Type: application/vnd.com.nsn.cumulocity.event+json
{
  "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
Authorization: Basic <<auth>>
Content-Type: <<content-type>>
Content-Length: 100
Content-Range: 0-399/*
<<content-body>>

Example response for first chunk:

HTTP/1.1 200 OK
Content-Type: application/vnd.com.nsn.cumulocity.event+json
{
  "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
Authorization: Basic <<auth>>
Content-Type: <<content-type>>
Content-Length: 100
Content-Range: 400-499/500
<<content-body>>

Example response for last chunk:

HTTP/1.1 201 Created
Location: <<url>>/event/events/<<eventId>>/binaries
Content-Type: application/vnd.com.nsn.cumulocity.event+json
{
  "self”: “<<url>>/event/binaries/<<eventId>>”,
  “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-Type: <<content-type>>
Content-Length: <<content-lenght>>
Authorization: Basic <<auth>>
<<content-body>>

Successful response:

HTTP/1.1 201 Created
Location: <<url>>/event/events/<<eventId>>/binaries
Content-Type: application/vnd.com.nsn.cumulocity.event+json
{
  "self”: “<<url>>/event/binaries/<<eventId>>”,
  “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:

HTTP/1.1 204 NO CONTENT

Example response when binary or event doesn’t exist

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