[Backport 12.4] [TASK] Improve information on ProductionExceptionHand…

…ler (#4386)

* [TASK] Improve information on ProductionExceptionHandler

In preparation for documentation of TYPO3-Documentation/Changelog-To-Doc#883

Releases: main, 12.4, 11.5

* Update Documentation/ApiOverview/ErrorAndExceptionHandling/ProductionExceptionHandler/Index.rst

* Update Documentation/ApiOverview/ErrorAndExceptionHandling/ProductionExceptionHandler/Index.rst

* Update Documentation/ApiOverview/ErrorAndExceptionHandling/ProductionExceptionHandler/Index.rst

* Update Documentation/ApiOverview/ErrorAndExceptionHandling/ProductionExceptionHandler/Index.rst

---------

Co-authored-by: lina.wolf <lwolf@w-commerce.de>
Co-authored-by: Chris Müller <2566282+brotkrueml@users.noreply.github.com>

Documentation/ApiOverview/ErrorAndExceptionHandling/ProductionExceptionHandler/Index.rst

@@ -1,18 +1,71 @@
-.. include:: /Includes.rst.txt
-.. index::Exceptions; ProductionExceptionHandler
-.. _error-handling-production-exception-handler:
+..  include:: /Includes.rst.txt
+..  index::Exceptions; ProductionExceptionHandler
+..  _error-handling-production-exception-handler:
 
 ============================
-Production Exception Handler
+Production exception handler
 ============================
 
 Functionality of the :php:`\TYPO3\CMS\Core\Error\ProductionExceptionHandler`:
 
--  Shows brief exception message ("Oops, an error occurred!") using
-   :php:`TYPO3\CMS\Core\Controller\ErrorPageController` and its attendant template.
+*   Shows brief exception message ("Oops, an error occurred!") using
+    :php:`\TYPO3\CMS\Core\Controller\ErrorPageController` and its attendant template.
+*   Logs exception messages via the :ref:`logging API <logging>`.
+*   Logs exception messages to the sys\_log table. Logged errors are displayed
+    in the belog extension (:guilabel:`Admin Tools > Log`). This will only work with an
+    existing DB connection.
 
--  Logs exception messages via the :ref:`logging API <logging>`.
+Depending on the :ref:`Logging writer configuration <logging-configuration-writer>`
+the exception output can be found for example in the following locations:
 
--  Logs exception messages to the sys\_log table. Logged errors are displayed
-   in the belog extension (:guilabel:`Admin Tools > Log`). This will only work with an
-   existing DB connection.
+:php:`\TYPO3\CMS\Core\Log\Writer\FileWriter`
+    In Composer-based installations the information can be found in directory
+    :path:`var/logs/`. In legacy installations in :path:`typo3temp/var/logs/`.
+:php:`\TYPO3\CMS\Core\Log\Writer\SyslogWriter`
+    Logs exception messages to the :sql:`sys_log` table. Logged errors are displayed
+    in the backend module :guilabel:`Admin Tools > Log`.
+
+Here you find a complete list of :ref:`Log writers <logging-writers>`.
+
+..  _error-handling-oops-an-error:
+
+Message "Oops, an error occurred!"
+==================================
+
+The generic error message "Oops, an error occurred!" is displayed when an
+exception or error happens within a TypoScript content object like
+:ref:`FLUIDTEMPLATE <t3tsref:cobj-template>` or a plugin. When the exception
+affects only one content element or plugin it is displayed in place of that
+elements. However, if it affects the content element representing the whole page
+like :ref:`PAGEVIEW <t3tsref:cobj-pageview>` only a plain page with this text on
+it is displayed.
+
+This message is displayed in :ref:`production context <Environment-context>`
+instead of a more detailed exception message. The detailed message can then be
+found in the log.
+
+..  _error-handling-oops-an-error-detail:
+
+Show detailed exception output
+------------------------------
+
+When the frontend debugging is activated, a detailed exception message is output
+instead of the generic "Oops, an error occurred!" message.
+
+By default, debugging is enabled in the
+:ref:`TYPO3 contexts <Environment-context>` starting with `Development`. It can
+also be enabled by setting
+:ref:`config.contentObjectExceptionHandler <t3tsref:setup-config-contentObjectExceptionHandler>`
+in TypoScript.
+
+..  _error-handling-oops-an-error-detail-admin:
+
+Example: prevent "Oops, an error occurred!" messages for logged-in admins
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+..  code-block:: typoscript
+    :caption: EXT:my_extension/Configuration/TypoScript/setup.typoscript
+
+    [backend.user.isAdmin]
+        config.contentObjectExceptionHandler = 0
+    [END]