Events#

Events execute Provisioning Workflows in response to a trigger. The trigger is an operation that is carried out on a selected model. The available actions for a selected model define the list of available operations.

Event instances to trigger are searched for as follows: the lower of:

  • the transaction hierarchy (in other words the transaction “breadcrumb”)

  • the triggering resource hierarchy

When an Event instance is defined, the following values are specified:

  • Workflow - the created Provisioning Workflow is selected.

  • Active - if the Event is to be enabled, it is set to be active. This means events can be created without being active.

  • Model Type - This is a part of the transaction. Operations on Model Types define the transaction.

  • Operation - the available operations depend on the selected Model Type.

  • Phase - the event can take place before or after the defined transaction. For example, if the Create Operation is available for the Model Type and the Phase is Pre Execution, then the event workflow is run before the Create Operation.

  • Synchronous - if enabled, the transaction is only carried out if the HTTP response from the HTTP request in the workflow shows the request was received, in other words the response is of the format HTTP 2xx. If the Event is not set to be Synchronous, in other words it is asynchronous, the transaction is carried out regardless of the HTTP response.

    Warning

    Always enable events as Synchronous, unless there is a good reason to set an event as asynchronous. Failed asynchronous events do not roll back the triggering transaction and can lead to unexpected issues.

A hierarchy context of the selected model is available to a Workflow in the case of events. In the case where a model allows for a Move operation and a Post Execution Phase is specified, this hierarchy value would be changed to the new hierarchy.

Consider for example the following transaction context data:

Pre event hierarchy: 5404f304c8e69d774458660e
Post event hierarchy: 5404f711c8e69d774458a92a

device/cucm/User Pre Asynchronous move:


Step 0 - Executing workflow (testEVPWF) with the following context data:
 {
    "input": {
        "device_pkid": "5404f345c8e69d7744586676"
    },
    "trigger": {
        "model_type": "device/cucm/User",
        "phase": "preexecution",
        "operation": "move",
        "trigger_model_type": "data/Event",
        "name": "testEV_cucmUser_Pre_async_move"
    },
    "resource_meta": {
        "model_type": "device/cucm/User",
        "pkid": "5405ba26c8e69d77445b8769",
        "hierarchy": "5404f304c8e69d774458660e",
        "device_pkid": "5404f345c8e69d7744586676"
    },


device/cucm/User Post Asynchronous move:


Step 0 - Executing workflow (testEVPWF) with the following context data:
 {
    "input": {
        "device_pkid": "5404f345c8e69d7744586676"
    },
    "trigger": {
        "model_type": "device/cucm/User",
        "phase": "postexecution",
        "operation": "move",
        "trigger_model_type": "data/Event",
        "name": "testEV_cucmUser_Post_async_move"
    },
    "resource_meta": {
        "model_type": "device/cucm/User",
        "pkid": "5405ba26c8e69d77445b8769",
        "hierarchy": "5404f711c8e69d774458a92a",
        "device_pkid": "5404f345c8e69d7744586676"
    },

The Provisioning Workflow is triggered from the lower of: the transaction hierarchy (eg. breadcrumb) and the hierarchy where the event instance is located.

To override this hierarchy in order that the workflow is run in the target hierarchy, use the {{ resource_meta.hierarchy }} macro for the workflow context hierarchy.

For example:

{
   "meta": {},
   "resources": [
      {
         "meta": {
             "model_type": "data/ProvisioningWorkflow",
             "pkid": "53fde2d02afa4356c87e45c4",
             "schema_version": "0.3.9",
             "hierarchy": "sys",
             "tags": []
         },
          "data": {
             "name": "__post_event_test",
             "parameters": {
                "max_workers": "1",
                "parallel": "false"
             },
             "workflow": [
                {
                  "entity_type": "model",
                  "hierarchy": "{{ resource_meta.hierarchy }}",
                  "entity": "data/Countries",
                  "method": "refresh",
                  "advanced_find_options": [
                      {
                          "model_attribute": "iso_country_code",
                          "mapped_value": "USA"
                      }
                    ],
                  "advanced_find_search_direction": "full_tree"
                }
             ]
          }
      }
   ]
 }