Core API

ext_emconf.php

Definition of extension properties

Name, category, status etc. Used by the EM. Also auto-written by EM when extensions are imported from repository.

Notice: If this file is not present the EM will not find the extension.

ext_localconf.php

Addition to "localconf.php" which is included if found. Should contain additional configuration of $TYPO3_CONF_VARS and may include additional PHP class files.

All 'ext_localconf.php' files of included extensions are included right after the typo3conf/localconf.php file has been included and database constants defined. Therefore you cannot setup database name, username, password though, because database constants are defined already at this point.

 
Notice: Observe rules for content of these files. See section on caching below.

ext_tables.php

Addition to "tables.php" which is included if found. Should contain configuration of tables, modules, backend styles etc. Everything which can be done in an "extTables" file is allowed here.

All 'ext_tables.php' files of loaded extensions are included right after the 'tables.php' file in the order they are defined in the global array TYPO3_LOADED_EXT but right before a general "extTables" file (defined with the var $typo_db_extTableDef_script in the typo3conf/localconf.php file, later set as the constant TYPO3_extTableDef_script). Thus a general "extTables" file in typo3conf/ may overrule any settings made by loaded extensions.

You should not use this file for setting up $TYPO3_CONF_VARS. See "ext_localconf.php".

Notice: Observe rules for content of these files. See section below.

ext_tables.sql

SQL definition of database tables.

This file should contain a table-structure dump of the tables used by the extension. It is used for evaluation of the database structure and is therefore important to check and update the database when an extension is enabled.
If you add additional fields (or depend on certain fields) to existing tables you can also put them here. In that case insert a CREATE TABLE structure for that table, but remove all lines except the ones defining the fields you need.
The ext_tables.sql file may not necessarily be "dumpable" directly to MySQL (because of the semi-complete table definitions allowed defining only required fields, see above). But the EM or Install Tool can handle this. The only very important thing is that the syntax of the content is exactly like MySQL made it so that the parsing and analysis of the file is done correctly by the EM.

ext_tables_static+adt.sql

Static SQL tables and their data.

If the extension requires static data you can dump it into a sql-file by this name.
Example for dumping mysql data from bash (being in the extension directory):

mysqldump --password=[password] [database name] [tablename] --add-drop-table > ./ext_tables_static.sql

--add-drop-table will make sure to include a DROP TABLE statement so any data is inserted in a fresh table.

You can also drop the table content using the EM in the backend.

Notice: The table structure of static tables needs to be in the ext_tables.sql file as well - otherwise an installed static table will be reported as being in excess in the EM!

ext_typoscript_constants.txt

Preset TypoScript constants

Deprecated (use static template files instead, see extMgm API description)

Such a file will be included in the constants section of all TypoScript templates.

ext_typoscript_setup.txt

Preset TypoScript setup

Deprecated (use static template files instead, see extMgm API description)

Such a file will be included in the setup section of all TypoScript templates.

ext_typoscript_editorcfg.txt

Preset TypoScript editor configuration

Deprecated (use static template files instead, see extMgm API description)

Such a file will be included in the "Backend Editor Configuration" section of all TypoScript templates.

ext_conf_template.txt

Extension Configuration template.

Configuration code in TypoScript syntax setting up a series of values which can be configured for the extension in the EM.

If this file is present the EM provides you with an interface for editing the configuration values defined in the file. The result is written as a serialized array to localconf.php file in the variable $TYPO3_CONF_VARS["EXT"]["extConf"][extension_key]

The content of the "res/" folder is used for filelists in configuration forms.

If you want to do user processing before the content from the configuration form is saved (or shown for that sake) there is a hook in the EM which is configurable with $TYPO3_CONF_VARS['SC_OPTIONS']['typo3/mod/tools/em/index.php']['tsStyleConfigForm'][] = "function reference"

ext_icon.gif

Extension Icon

18x16 gif icon for the extension.

(*/) locallang*.php

Localization values.

The filename "locallang.php" (or any file matching locallang*.php) is used for traditional definition of language labels in the $LOCAL_LANG array. If you use this name consistently those files will be detected by the translation tool!

Notice: PLEASE DO ONLY put the definition of the variable $LOCAL_LANG into this file and don't rely on comments in the file. The file will be automatically updated by the extension repository when translations are applied.

class.ext_update.php

Local Update tool class

If this file is found it will install a new menu item, "UPDATE", in the EM when looking at details for the extension. When this menu item is selected the class inside of this file (named "ext_update") will be instantiated and the method "main()" will be called and expected to return HTML content.

Also you must add the function "access()" and make it return a boolean value whether or not the menu item should be shown. This feature is meant to let you disable the update tool if you can somehow detect that it has already been run and doesn't need to run again.
The point of this file is to give extension developers the possibility to provide an update tool if their extensions in newer versions require some updates to be done. For an example, see "newloginbox" extension.

ext_api_php.dat

PHP API data

A file containing a serialized PHP array with API information for the PHP classes in the extension. The file is created - and viewed! - with tools found in the extension "extdeveval" (Extension Development Evaluator)

pi*/

Typical folder for a frontend plugin class.

mod*/

Typical folder for a backend module.

res/

Extensions normally consist of other files: Classes, images, html-files etc. Files not related to either a frontend plugin (pi/) or backend module (mod/) might be put in a subfolder of the extension directory named "res/" (for "resources") but you can do it as you like (inside of the extension directory that is).
The "res/" folder content will be listed as files you can select in the configuration interface.

Files in this folder can also be selected in a selector box if you set up Extension configuration in a "ext_conf_template.txt" file.