.. include:: /Includes.rst.txt






.. _globals-variables:

Global variables
^^^^^^^^^^^^^^^^

.. note::
   Variables in italics *may* be set in a script prior to
   inclusion of :file:`init.php` so they are optional.

.. note::

   To make the table below a bit more compact, namespaces were left out. Here
   are the fully qualified class names referred to below:

   - "SystemEnvironmentBuilder" = :code:`\TYPO3\CMS\Core\Core\SystemEnvironmentBuilder`
   - "Bootstrap" = :code:`\TYPO3\CMS\Core\Core\Bootstrap`


.. t3-field-list-table::
 :header-rows: 1

 - :Variable,20: Global variable
   :Defined,20: Defined in
   :Description,50: Description
   :FE,10: Avail. in FE


 - :Variable:
         $TYPO3\_CONF\_VARS
   :Defined:
         :file:`typo3/sysext/core/Configuration/DefaultConfiguration.php`
   :Description:
         TYPO3 configuration array. Please refer to mentioned file where each option is described in detail
         as comments. The same comments are also available in the Install Tool
         under the menu "All Configuration".
   :FE:
         Yes


 - :Variable:
         $TYPO3\_LOADED\_EXT
   :Defined:
         Bootstrap::populateTypo3LoadedExtGlobal()
   :Description:
         Array with all loaded extensions listed with a set of paths. You can
         check if an extension is loaded by the function
         :code:`\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::isLoaded($key)` where :code:`$key` is the extension key.
   :FE:
         Yes


 - :Variable:
         $TYPO3\_DB
   :Defined:
         Bootstrap::initializeTypo3DbGlobal()
   :Description:
         An instance of the TYPO3 DB wrapper class, :code:`\TYPO3\CMS\Core\Database\DatabaseConnection`.

         You have to use this object for all interaction with the database.

         :code:`\TYPO3\CMS\Core\Database\DatabaseConnection` contains MySQL wrapper functions so you easily swap all
         hardcoded MySQL calls with function calls to :code:`$GLOBALS['TYPO3_DB']->`.
   :FE:
         Yes


 - :Variable:
         $EXEC\_TIME
   :Defined:
         SystemEnvironmentBuilder::initializeGlobalTimeTrackingVariables()
   :Description:
         Is set to :code:`time()` so that the rest of the script has a common value
         for the script execution time.
   :FE:
         YES


 - :Variable:
         $SIM\_EXEC\_TIME
   :Defined:
         SystemEnvironmentBuilder::initializeGlobalTimeTrackingVariables()
   :Description:
         Is set to :code:`$EXEC_TIME` but can be altered later in the script if we
         want to simulate another execution-time when selecting from e.g. a
         database (used in the frontend for preview of future and past dates)
   :FE:
         Yes


 - :Variable:
         $PARSETIME\_START
   :Defined:
         SystemEnvironmentBuilder::initializeGlobalTimeTrackingVariables()
   :Description:
         Time in milliseconds right after inclusion of the configuration.
   :FE:
         No


 - :Variable:
         *$TYPO3\_AJAX*
   :Defined:
         ajax.php
   :Description:
         Set to true to indicate that an AJAX call is being processed
   :FE:
         No


 - :Variable:
         $PAGES\_TYPES
   :Defined:
         typo3/sysext/core/ext_tables.php
   :Description:
         See :ref:`page-types`
   :FE:
         (occasionally)


 - :Variable:
         $TCA
   :Defined:
         Bootstrap::loadExtensionTables()
   :Description:
         See :doc:`TCA Reference <t3tca:Index>`
   :FE:
         Yes, partly


 - :Variable:
         $TBE\_MODULES
   :Defined:
         typo3/sysext/core/ext_tables.php
   :Description:
         The backend main/sub-module structure. See section elsewhere plus
         source code of class :code:`\TYPO3\CMS\Backend\Module\ModuleLoader` which also includes some
         examples.
   :FE:
         (occasionally)


 - :Variable:
         $TBE\_STYLES
   :Defined:
         typo3/sysext/core/ext_tables.php
   :Description:
         Contains information related to BE skinning.
   :FE:
         (occasionally)


 - :Variable:
         $T3\_SERVICES
   :Defined:
         SystemEnvironmentBuilder::initializeGlobalVariables()
   :Description:
         Global registration of services.
   :FE:
         Yes


 - :Variable:
         $T3\_VAR
   :Defined:
         SystemEnvironmentBuilder::initializeGlobalVariables()
   :Description:
         Space for various internal global data storage in TYPO3. Each key in
         this array is a data space for an application. Keys currently defined
         for use is:

         ['callUserFunction'] + ['callUserFunction\_classPool']: Used by
         :code:`\TYPO3\CMS\Core\Utility\GeneralUtility::callUserFunction` to store singleton objects.

         ['getUserObj'] : Used by :code:`\TYPO3\CMS\Core\Utility\GeneralUtility::getUserObj` to store singleton
         objects.

         ['RTEobj'] : Used to hold the current RTE object if any. See
         :code:`\TYPO3\CMS\Backend\Utility\BackendUtility`.

         ['ext'][ *extension-key* ] : Free space for extensions.
   :FE:
         Yes




 - :Variable:
         $BE\_USER
   :Defined:
         Bootstrap::initializeBackendUser()
   :Description:
         Backend user object. See :ref:`be-user`.
   :FE:
         (depends)


 - :Variable:
         *$TBE\_MODULES\_EXT*
   :Defined:
         [In ext\_tables.php files of extensions]
   :Description:
         Used to store information about modules from extensions that should be
         included in "function menus" of real modules. See the Extension API
         for details.
   :FE:
         (occasionally)


 - :Variable:
         *$TCA\_DESCR*
   :Defined:
         [tables.php files]
   :Description:
         Can be set to contain file references to local lang files containing
         :code:`TCA_DESCR` labels. See section about Context Sensitive Help.
   :FE:
         No


.. _globals-exploring:

Exploring global variables
""""""""""""""""""""""""""

Many of the global variables described above can be inspected using the
Admin Tools > Configuration module.

.. warning::
   This module is always viewed in the BE context. Variables defined
   only in the FE context will not be visible there.

.. figure:: ../../../Images/ConfigurationModule.png
   :alt: The Configuration module in Admin Tools

   Viewing the :code:`$TCA` array using the Admin Tools > Configuration module