Update checkbox value through plugin (Craft 3)

Question

I'm trying to update a checkbox field of an entry through a plugin service. I tried two things:

1. Get the field values with $entry->fieldHandle->getOptions(), then manipulating the resulting array, then set the value with $entry->fieldHandle->setOptions()

   $contact = Entry::find()
       ->id(...)
       ->one();
   $newsletters = $contact->contactNewsletterSubscriptions->getOptions();
   $newsletters[$index]->selected = false;
   $contact->contactNewsletterSubscriptions->setOptions($newsletters);
   Craft::$app->elements->saveElement($contact);
   

(where $index is the array index of the setting I want to change)

-> this didn't work (no error message, changes just didn't get saved)

2. If I make a var_dump of $contact, the field contactNewsletterSubscriptions is showed as string. I played around with json_decode and serialize to get the right formatting (it looks exactly as when doing a var_dump):

   $newsletterSubscriptions = json_decode($contact->contactNewsletterSubscriptions->serialize());
   $index = array_search($newsletterName, $newsletterSubscriptions);
   unset($newsletterSubscriptions[$index]);
   $contact->contactNewsletterSubscriptions = (string)json_encode(array_values($newsletterSubscriptions))
   

-> doesn't work either; value gets saved as string; if I later call getOptions() on the field I'm getting "Call to a member function getOptions() on string"

Any idea how I can change the status of a checkbox from selected = true to selected = false?

Best regards.

Answer 1

You need to set the field value, not the options

$entry->setFieldValue('fieldHandle' [
    'value1', 'value2'
});
Craft::$app->getElements()->saveElement($entry);

If you want to change the values, the easiest method is

$allOptions = $entry->getFieldValue('fieldHandle');
$selected = [];
foreach($allOptions as $option){
    if($option->selected){
         $selected[] = $option->value;
    }
}
// unset a value
unset($selected[1]);
// add another value
$selected[] = 'anotherValue';
$entry->setFieldValue('fieldHandle', $selected);
Craft::$app->getElements()->saveElement($entry);

edit

Another approach - a little bit less code and more general since it's the same for every single field in Craft - but more resource heavy

$field = Craft::$app->getFields()->getFieldByHandle('handle);
$selected = $field->serializeValue($entry->getFieldValue('handle'), $entry);
$selected[] = 'anotherValue';
$entry->setFieldValue('handle', $selected);
Craft::$app->getElements()->saveElement($entry);