post hook edit entity

Question

We have a post hook that sends some data to an external api when a participant is created or edited.

function kavo_civicrm_post($op, $objectName, $objectId, &$objectRef) { if (($op == 'create' || $op == 'edit') && $objectName == 'Participant') {

Based on the response of that api a custom field on the response of that API a couple of custom fields on the participant should be set. This is done using the php api, but results in a loop with the post hook being called, even when following the add_callback instructions in the post hook documentation.

try { civicrm_api3('Kavo', 'createparticipant', ['participant_id' => $objectId]); $successState = CRM_Kavo_Status::KAVO_ATTENDED(); CRM_Core_Transaction::addCallback(CRM_Core_Transaction::PHASE_POST_COMMIT, 'set_kavo_state', [$objectId, $successState]); } catch (CiviCRM_API3_Exception $ex) { $contact = $worker->getContact($participant); CRM_Core_Session::setStatus($ex->getMessage(), ts("Failed sending participant %1 to KAVO.", [1 => $contact['display_name']]), 'error'); $failedState = CRM_Kavo_Status::KAVO_FAILED(); CRM_Core_Transaction::addCallback(CRM_Core_Transaction::PHASE_POST_COMMIT, 'set_kavo_state', [$objectId, $failedState, $ex->getMessage()]); }

function set_kavo_state($participant_id, $state, $message='success'){ $kavo_status_field = CRM_Kavo_Field::KAVO_PARTICIPANT_STATUS(); $kavo_message_field = CRM_Kavo_Field::KAVO_PARTICIPANT_MESSAGE(); civicrm_api3('Participant', 'create', array( 'id' => $participant_id, $kavo_status_field => $state, $kavo_message_field => $message )); }

The kavo create_participant call does our call to the external api Is there another way to edit the participant being edited in a post hook?

Answer 1

The participant create in set_kavo_state() triggers your post hook again which then calls set_kavo_state() etc. You need to determine whether the post hook is being called just to update the $kavo_status_field and $kavo_message_field fields - and therefore not set up another callback to set_kavo_state().

Do you actually need to call your external API for participant edits? If you could limit the post hook to only trigger on 'create' you would avoid the loop.

Answer 2

You have two choices:

• Use hook_civicrm_pre instead of hook_civirm_post. This isn't ideal because it's synchronous and will slow down your writes.
• Since you're updating custom fields only, continue to use hook_civicrm_post, but instead of calling Participant.create, call CustomValue.create, which won't trigger the post hook a second time.

Answer 3

If you are using Drupal, you can use the Drupal static cache infrastructure to break the cycle. In this particular example, the static cache is only available for one page load / http request. You can set a database cache as well, see References below for detailed explanation and instructions

function set_kavo_state($participant_id, $state, $message='success'){
  $stop = &drupal_static(__FUNCTION__);
  // could use more logic in this conditional if need be ... but at least you will know if you've come back a second time...
  if (!isset($stop)) {
    $kavo_status_field = CRM_Kavo_Field::KAVO_PARTICIPANT_STATUS();
    $kavo_message_field = CRM_Kavo_Field::KAVO_PARTICIPANT_MESSAGE();
    civicrm_api3('Participant', 'create', array(
      'id' => $participant_id,
      $kavo_status_field => $state,
      $kavo_message_field => $message
    ));
    $stop = 1;
  }
}

References: Drupal API documentation A Beginner's Guide to Caching Data in Drupal 7