6장. OpenShift Serverless Logic overview

An event state consists of one or more event definitions. Event definitions are combined to designate the CloudEvent types that the event state listens to. You can use the event state to start a new workflow instance upon the reception of a designated CloudEvent, or to pause the execution of an existing workflow instance until a designated CloudEvent is received.

In an event state definition, the onEvents property is used to group the CloudEvent types that might trigger the same set of actions. The exclusive property in an event definition indicates how an event match is calculated. If the value of exclusive property is false, then all CloudEvent types in the eventRefs array must be received for a match to occur. Otherwise, the reception of any referenced CloudEvent type is considered a match.

The following example shows event definitions, consisting of two CloudEvent types, including noisy and silent:

"events": [
    {
      "name": "noisyEvent",
      "source": "",
      "type": "noisy",
      "dataOnly" : "false"
    },
    {
      "name": "silentEvent",
      "source": "",
      "type": "silent"
    }
  ]

To indicate that an event match occurs when both noisy and silent CloudEvent types are received and to execute different actions for both CloudEvent types, define an event state containing both event definitions in separate onEvent items and set the exclusive property to false.

{
    "name": "waitForEvent",
    "type": "event",
    "onEvents": [
      {
        "eventRefs": [
          "noisyEvent"
         ],
         "actions": [
           {
             "functionRef": "letsGetLoud"
           }
         ]
      },
      {
        "eventRefs": [
           "silentEvent"
        ],
        "actions": [
          {
            "functionRef": "beQuiet"
          }
        ]
      }
    ]
    ,
    "exclusive": false
  }