Formatter and Handler Create custom Update handler

• Create custom update Handler

Create custom update Handler

If the two handlers do not meet your expectations, you can (of course) create your own. If you look at the interface (\Watcher\UpdateHandler), you see that this is easy:

interface UpdateHandler
{

    public function handleUpdate(ChangedField $changedField, ValueFormatter $formatter, WatchedEntity $entity);

}

The method UpdateHandler::handleUpdate() is called for each field individually. Grouping is not possible since doctrines flush process can be executed several times during the runtime.

The three parameters should be self-explanatory:

• The ChangedField instance is a non-persistent domain object which contains methods to receive the following property details:
  • The field name (is equal to the property name from your entity)
  • The field label (a user-friendly representation from your entity field)
  • The old value*
  • The new value*
• The ValueFormatter handles the job for the upcoming string conversion. It was set when creating the FlushListener OR overridden in your entity (see "Usage" > "Annotation options" for more information)
• WatchedEntity is the entity which is related to the changed field

*) Keep in mind that this values are not "stringified". Have a look at the ValueFormatter for further information.

With this in mind, you can create your own handler. Let's say you want to receive an SMS on your mobile phone when a a user changes his email address:

Create a new class and dont forget to implement the interface \Watcher\UpdateHandler:

namespace Example;

use Watcher\ChangedField\ChangedField;
use Watcher\Entity\WatchedEntity;
use Watcher\UpdateHandler;
use Watcher\ValueFormatter;

class SmsHandler implements UpdateHandler {

    public function handleUpdate(ChangedField $changedField, ValueFormatter $formatter, WatchedEntity $entity)
    {

        if(($entity instanceof \Example\Entity\User) && ('emailAddress' == $changedField->getFieldName())) {

            $newEmailAddress = $formatter->formatValue($changedField->getNewValue());
            $message = sprintf('Wohoo! %s has changed his email adress to "%s"!', $entity->getUsername(), $newEmailAddress);

            SomeSmsSenderService::send($message);
        }

    }

}

The last step is to assign your new handler within the configuration:

$updateHandler = new SmsHandler();
$em = EntityManager::create($dbParams, $config, Watcher::createEventManager($updateHandler));