Altering form values

Question

I have a Custom Group with two custom fields: Field A is a view only input field (ID: custom_32) Field B is a select with a few options (ID: custom_33).

When the user selects one option from Field B and hits save I would like to add a value to Field A based on the selected option.

Which hook shall I use for this?

I tried civicrm_preProcess, civicrm_postProcess and civicrm_validateForm.

My aproach to the problem is to alter the submitted (empty) value in the form object but it doesn't seem to work.

function insert_value_for_b($formName, &$form){
    //determine $newValue
    //other business logic
    $data = &$form->controller->container();
    $data['values']['CustomData'][$customIDforB] = $newValue;
}

Could someone advise please?

Answer 1

View only fields can only be updated via the API, see: https://issues.civicrm.org/jira/browse/CRM-17843

So you could use one of the hooks (eg: hook_civicrm_pre) to 'detect' when that field has changed, and read the value, and then use the API to set the other value. _pre might be more reliable than the form hooks, as the field might be set by other methods than by submitting a form.

For example:

function foo_civicrm_pre($op, $objectName, $id, &$params) {
  if ($objectName == 'Contact' && empty($params['custom_xxx'])) {
    // make an API call to set custom_yyy
  }
}