--- title: "Code editor" manual: "TYPO3 Explained" version: "13.4" permalink: "https://docs.typo3.org/permalink/t3coreapi:code-editor@13.4" source: "ApiOverview/CodeEditor/Index.rst" rendered: "2026-09-20T16:02:56+00:00" --- # Code editor {#code-editor} The code editor functionality was moved from the optional "t3editor" system extension into the "backend" system extension. The code editor is therefore always available.Checks whether the previous system extension is installed via \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::isLoaded('t3editor') are now obsolete. The code editor provides a backend editor with syntax highlighting. The editor is used by TYPO3 itself for [TCA fields with type "text" and renderType "codeEditor"](https://docs.typo3.org/m/typo3/reference-tca/13.4/en-us/ColumnsConfig/Type/Text/T3Editor/Index.html#columns-text-renderType-codeEditor) and in the module **File > Filelist**. Under the hood, [CodeMirror](https://github.com/codemirror/codemirror5) is used. - [Usage in TCA](https://docs.typo3.org/permalink/t3coreapi:usage-in-tca@13.4) - [Extend the code editor](https://docs.typo3.org/permalink/t3coreapi:extend-the-code-editor@13.4) ## Usage in TCA {#code-editor-usage-tca} Extensions may configure backend fields to use the code editor by TCA. The editor is only available for fields of type [text](https://docs.typo3.org/m/typo3/reference-tca/13.4/en-us/ColumnsConfig/Type/Text/Index.html#columns-text). By setting the `renderType` to `codeEditor` the syntax highlighting can be activated. By setting the property [format](https://docs.typo3.org/m/typo3/reference-tca/13.4/en-us/ColumnsConfig/Type/Text/T3Editor/Index.html#columns-text-properties-format) the mode for syntax highlighting can be chosen. Allowed values: - `css` - `html` - `javascript` - `json` - `php` - `sql` - `typoscript` - `xml` - and any [custom mode](https://docs.typo3.org/permalink/t3coreapi:code-editor-register-mode@13.4) registered by an extension. ### Example {#code-editor-usage-tca-example} **Excerpt of TCA definition (EXT:my_extension/Configuration/TCA/tx_myextension_domain_model_mytable.php)** ```php [ 'columns' => [ 'codeeditor1' => [ 'label' => 'codeEditor_1 format=html, rows=7', 'description' => 'field description', 'config' => [ 'type' => 'text', 'renderType' => 'codeEditor', 'format' => 'html', 'rows' => 7, ], ], ], ] ``` Displays an editor like the following: ![A code editor with syntax highlighting for HTML](../../Images/ManualScreenshots/CodeEditor/CodeEditor.png) ## Extend the code editor {#code-editor-extend} Custom modes (used for syntax highlighting) and addons can be registered. [CodeMirror](https://github.com/codemirror/codemirror5) delivers a lot more modes and addons than registered in the code editor by default. More supported addons and modes are available at: - [https://github.com/codemirror/codemirror5/tree/5.27.4/addon](https://github.com/codemirror/codemirror5/tree/5.27.4/addon) - [https://github.com/codemirror/codemirror5/tree/5.27.4/mode](https://github.com/codemirror/codemirror5/tree/5.27.4/mode) To register custom addons and modes, extensions may have these two files to extend the code editor: - `Configuration/Backend/T3editor/Addons.php` - `Configuration/Backend/T3editor/Modes.php` Both files return an array, as known as in [TCA](https://docs.typo3.org/m/typo3/reference-tca/13.4/en-us/Index.html#start) and [backend routes](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-backend-routes@13.4), for example. ### Register an addon {#code-editor-register-addon} To register an addon, the following code may be used: **EXT:my_extension/Configuration/Backend/T3editor/Addons.php** ```php [ 'module' => JavaScriptModuleInstruction::create( '@codemirror/addon', 'addon', )->invoke(), 'cssFiles' => [ 'EXT:my_extension/Resources/Public/Css/MyAddon.css', ], 'options' => ['foobar' => 'baz'], ], 'modes' => ['htmlmixed', 'xml'], ]; ``` The following configuration options are available: - **\** - *Type:* string - *Required:* true Represents the unique identifier of the module (`my/addon` in this example). #### module {#code-editor-register-addon-module} - **module** - *Type:* string - *Required:* true Holds the JavaScriptModuleInstruction of the CodeMirror module. #### cssFiles {#code-editor-register-addon-cssfiles} - **cssFiles** - *Type:* array Holds all CSS files that must be loaded for the module. #### options {#code-editor-register-addon-options} - **options** - *Type:* array Options that are used by the addon. #### modes {#code-editor-register-addon-modes} - **modes** - *Type:* array If set, the addon is only loaded if any of the modes supplied here is used. ### Register a mode {#code-editor-register-mode} To register a mode, the following code may be used: **EXT:my_extension/Configuration/Backend/T3editor/Modes.php** ```php [ 'module' => 'cm/mode/css/css', 'extensions' => ['css'], ], ]; ``` The following configuration options are available: - **\** - *Type:* string - *Required:* true Represents the unique identifier and format code of the mode (`css` in this example). The format code is used in TCA to define the CodeMirror mode to be used. Example: ```php $GLOBALS['TCA']['tt_content']['types']['css']['columnsOverrides']['bodytext']['config']['format'] = 'css'; ``` #### module {#code-editor-register-mode-module} - **module** - *Type:* string - *Required:* true Holds the JavaScriptModuleInstruction of the CodeMirror module. #### extensions {#code-editor-register-mode-extensions} - **extensions** - *Type:* array Binds the mode to specific file extensions. This is important for using the code editor in the module **File > Filelist**. #### default {#code-editor-register-mode-default} - **default** - *Type:* bool If set, the mode is used as fallback if no sufficient mode is available. By factory default, the default mode is `html`.