/**
* {@inheritdoc}
*/
public function preSave()
{
parent::preSave();
// Merge field defaults on top of global ones.
$default_tags = metatag_get_default_tags();
// Get the value about to be saved.
$current_value = $this->value;
$current_tags = unserialize($current_value);
// Only include values that differ from the default.
// @TODO: When site defaults are added, account for those.
$tags_to_save = [];
foreach ($current_tags as $tag_id => $tag_value) {
if (!isset($default_tags[$tag_id]) || $tag_value != $default_tags[$tag_id]) {
$tags_to_save[$tag_id] = $tag_value;
}
}
// Update the value to only save overridden tags.
$this->value = serialize($tags_to_save);
}
/**
* {@inheritdoc}
*/
public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state)
{
$item = $items[$delta];
$default_tags = metatag_get_default_tags();
// Retrieve the values for each metatag from the serialized array.
$values = array();
if (!empty($item->value)) {
$values = unserialize($item->value);
}
// Populate fields which have not been overridden in the entity.
foreach ($default_tags as $tag_id => $tag_value) {
if (!isset($values[$tag_id]) && !empty($tag_value)) {
$values[$tag_id] = $tag_value;
}
}
// Create the form element.
$element = $this->metatagManager->form($values, $element);
return $element;
}
