Implementing tokens and tokenValues hooks for Event custom field

Question

I'm trying to implement a hook for inserting Event custom fields into Scheduled reminders; however, I'm not a developer so I'm really not sure what the code needs to look like. The custom field is custom_115 (Learning Materials link), which I know is the correct field as I located it using the API Explorer. The problem for me has been the hooks; not really understanding the structure. I'm running CiviCRM 5.7.2 on WordPress. I've pasted the following code (which I pieced together from various sources, and partly guessed) into my functions.php file but I know it's wrong and I don't know how to get it to work:

<?php 
/* CiviCRM token addition for custom_115 */
function civicrm_tokens(&$tokens) {
  $tokens['event'] = array(
    'event.custom_115' => 'Custom 115',
    );
}


/**
* Populates a token named "custom_115" with the value from a custom field 
* (id 115) for use in Scheduled Reminders
* Implements hook_civicrm_tokenValues().
*/

function civicrm_tokenValues(&$values, $cids, $job = null, $tokens = array(), $context = null) {
static $events = array();

  if (is_numeric($cids)) {
    // We're being called by CRM/Core/BAO/ActionSchedule.php:465
    // Params are structured differently than they're supposed to be, but we 
    // can work with it. See https://civicrm.stackexchange.com/questions/3573/can-tokenvalue-hooks-be-used-in-scheduled-reminder-emails

if ($event_id = CRM_Utils_Array::value('event.event_id', $values)) {
  // We've been passed an event ID

  if (!array_key_exists($event_id, $events)) {
    // We haven't looked up the custom field value yet

    // Fetch the custom field value from the database
    $event = civicrm_api3('Event', 'getsingle', array(
      'sequential' => 1,
      'return' => "custom_115",
      'id' => $event_id,
    ));

  $val = CRM_Utils_Array::value('custom_115', $event);

  // Keep this value in memory to use with the other event participants
  $events[$event_id] = $val;

  } else {
    // We stored the value previously
    $val = $events[$event_id];
  }

  $values['event.custom_115'] = $val;
  }

 }
}
?>

I'm assuming that if it is set up properly, I'll be able to locate "Custom_115" as an option in the Tokens list - is that right? Any help/advice would be appreciated. Thanks

Answer 1

The code doesn't go in functions.php, you need to create a little extension. See https://docs.civicrm.org/dev/en/latest/extensions.