How to use presave hook to save a field value as node title?

Question

I have a custom date field in a node type 'day'. When the node is saved (or edited then saved), I would like to get the field_date value (not the published date) and save it into the title field.

I would like to know how, perhaps using a module to:

hook_presave

• GET FIELD VALUE

• SET TITLE AS FIELD VALUE

• SAVE NODE

Answer 1

You need to implement the hook_entity_presave()

/**
 * Implements hook_entity_presave().
 */
function YOUR_MODULE_entity_presave(Drupal\Core\Entity\EntityInterface $entity) {
  switch ($entity->bundle()) {
    // Here you modify only your day content type
    case 'day':
      // Setting the title with the value of field_date.
      $entity->setTitle($entity->get('field_date')->value);
     break;
  }
}

Answer 2

For entity of type profile i have used below code

/**
 * Implements hook_entity_presave().
 */
function YOUR_MODULE_entity_presave(Drupal\Core\Entity\EntityInterface $entity) {
  if ($entity->getEntityType()->id() == 'profile') {
    $zipcode = $entity->field_zip_code->value;
    $url = "http://maps.googleapis.com/maps/api/geocode/json?address=".$zipcode."&sensor=false";
    $details=file_get_contents($url);
    $result = json_decode($details,true);
    $lat=$result['results'][0]['geometry']['location']['lat'];
    $lng=$result['results'][0]['geometry']['location']['lng'];
    $entity->field_geolocation->lat = $lat;
    $entity->field_geolocation->lng = $lng;
 }
}

Answer 3

For entity of type user

/**
 * Implements hook_entity_presave().
 */
function YOUR_MODULE_entity_presave(Drupal\Core\Entity\EntityInterface $entity) {
  $entity->field_uhid->value = 'testing';     //set value for field
}

Answer 4

This worked for me to get and set the date field value using presave hook based on content type

/**
 * Implements hook_entity_presave().
 */

function YOUR_MODULE_global_entity_presave(Drupal\Core\Entity\EntityInterface $entity) 
{
  if ($entity->bundle() == 'blog') {
    $published = $entity->get('created')->value;
    $entity->set('field_published_date', date('Y-m-d\TH:i:s', $published));
 }
}

Answer 5

You can alter and save the title to any available field using Automatic Entity Label https://www.drupal.org/project/auto_entitylabel