Attention

TYPO3 v8 has reached its end-of-life March 31st, 2020 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.

There is no further ELTS support. It is recommended that you upgrade your project and use a supported version of TYPO3.

Bootstrapping¶

TYPO3 CMS has a clean bootstrapping process driven mostly by class \TYPO3\CMS\Core\Core\Bootstrap. This class contains a host of methods each responsible for a little step along the initialization of a full TYPO3 process, be it the backend or other contexts.

Some contexts add their own bootstrap class (like the command line, which additionally requires \TYPO3\CMS\Core\Core\CliBootstrap.

Note

The frontend's bootstrapping process is not yet fully encapsulated in a bootstrap class.

Warning

This boostrapping API is internal and may change any time in the near future even in minor updates. It is thus discouraged to use it in third party code. Choose this solution only if other extensbility features such as Hooks, Signals or XCLASS are not enough to reach your goals.

One can see the bootstrapping process in action in file

typo3/init.php:

define('TYPO3_MODE', 'BE');

require 'sysext/core/Classes/Core/Bootstrap.php';

\TYPO3\CMS\Core\Core\Bootstrap::getInstance()
   ->baseSetup('typo3/')
   ->redirectToInstallToolIfLocalConfigurationFileDoesNotExist('../')
   ->startOutputBuffering()
   ->loadConfigurationAndInitialize()
   ->loadTypo3LoadedExtAndExtLocalconf(TRUE)
   ->applyAdditionalConfigurationSettings()
   ->initializeTypo3DbGlobal()
   ->checkLockedBackendAndRedirectOrDie()
   ->checkBackendIpOrDie()
   ->checkSslBackendAndRedirectIfNeeded()
   ->checkValidBrowserOrDie()
   ->loadExtensionTables(TRUE)
   ->initializeSpriteManager()
   ->initializeBackendUser()
   ->initializeBackendUserMounts()
   ->initializeLanguageObject()
   ->initializeModuleMenuObject()
   ->initializeBackendTemplate()
   ->endOutputBufferingAndCleanPreviousOutput()
   ->initializeOutputCompression();

Note that most methods of the Bootstrap class must be called in a precise order. It is perfectly possible to define one's own bootstrapping process, but care should be taken about the call order.

Also note that all bootstrapping methods return the instance of the Bootstrap class itself, allowing calls to be chained.

Application Context¶

Each request, no matter if it runs from the command line or through HTTP, runs in a specific application context. TYPO3 CMS provides exactly three built-in contexts:

Production (default) - should be used for a live site
Development - used for development
Testing - is only used internally when executing TYPO3 core tests. It must not be used otherwise.

The context TYPO3 runs in is specified through the environment variable TYPO3_CONTEXT. It can be set on the command line:

# run the TYPO3 CMS CLI commands in development context
TYPO3_CONTEXT=Development ./typo3/cli_dispatch.phpsh

or be part of the web server configuration:

# In your Apache configuration (either .htaccess or vhost)
# you can either set context to static value with:
SetEnv TYPO3_CONTEXT Development

# Or set context depending on current host header
# using mod_rewrite module
RewriteCond %{HTTP_HOST} ^dev\.example\.com$
RewriteRule .? - [E=TYPO3_CONTEXT:Development]

RewriteCond %{HTTP_HOST} ^staging\.example\.com$
RewriteRule .? - [E=TYPO3_CONTEXT:Production/Staging]

RewriteCond %{HTTP_HOST} ^www\.example\.com$
RewriteRule .? - [E=TYPO3_CONTEXT:Production]

# or using setenvif module
SetEnvIf Host "^dev\.example\.com$" TYPO3_CONTEXT=Development
SetEnvIf Host "^staging\.example\.com$" TYPO3_CONTEXT=Production/Staging
SetEnvIf Host "^www\.example\.com$" TYPO3_CONTEXT=Production

# In your Nginx configuration, you can pass the context as a fastcgi parameter
location ~ \.php$ {
   include         fastcgi_params;
   fastcgi_index   index.php;
   fastcgi_param   TYPO3_CONTEXT  Development/Dev;
   fastcgi_param   SCRIPT_FILENAME  $document_root$fastcgi_script_name;
}

Custom Contexts¶

In certain situations, more specific contexts are desirable:

a staging system may run in a Production context, but requires a different set of credentials than the production server.
developers working on a project may need different application specific settings but prefer to maintain all configuration files in a common Git repository.

By defining custom contexts which inherit from one of the three base contexts, more specific configuration sets can be realized.

While it is not possible to add new "top-level" contexts at the same level like Production and Testing, you can create arbitrary sub-contexts, just by specifying them like <MainContext>/<SubContext>.

For a staging environment a custom context Production/Staging may provide the necessary settings while the Production/Live context is used on the live instance.

Note

This even works recursively, so if you have a multiple-server staging setup, you could use the context Production/Staging/Server1 and Production/Staging/Server2 if both staging servers needed different configuration.

Attention

Testing Is reserved for internal use when executing TYPO3 core functional and unit tests It must not be used otherwise. Instead sub-contexts must be used: Production/Testing or Development/Testing

Usage Example¶

The current Application Context is set very early in the bootstrap process can be accessed through public API for example in the AdditionalConfiguration.php file to automatically set different configuration for different contexts.

In file typo3conf/AdditionalConfiguration.php:

switch (\TYPO3\CMS\Core\Utility\GeneralUtility::getApplicationContext()) {
   case 'Development':
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['displayErrors'] = 1;
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['devIPmask'] = '*';
      break;
   case 'Production/Staging':
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['displayErrors'] = 0;
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['devIPmask'] = '192.168.1.*';
      break;
   default:
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['displayErrors'] = 0;
      $GLOBALS['TYPO3_CONF_VARS']['SYS']['devIPmask'] = '127.0.0.1';
}