Error action 

Extbase offers an out of the box handling for errors. Errors might occur during the mapping of incoming action arguments. For example, an argument can not be mapped or validation did not pass.

How it works 

  1. Extbase will try to map all arguments within ActionController. During this process arguments will also be validated.
  2. If an error occurred, the class will call the $this->errorMethodName instead of determined $this->actionMethodName.

  3. The default is to call errorAction() which will:

    1. Clear cache in case persistence.enableAutomaticCacheClearing is activated and current scope is frontend.
    2. Add an error Flash Message by calling addErrorFlashMessage(). It will in turn call getErrorFlashMessage() to retrieve the message to show.
    3. Return the user to the referring request URL. If no referrer exists, a plain text message will be displayed, fetched from getFlattenedValidationErrorMessage().