---
title: "Configure custom backend preview for content element"
manual: "TYPO3 Explained"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3coreapi:configurece-preview@main"
source: "ApiOverview/ContentElements/CustomBackendPreview.rst"
rendered: "2026-09-22T15:26:06+00:00"
---

# Configure custom backend preview for content element {#configurece-preview}

To allow editors a smoother experience, all custom content elements and plugins
should be configured with a corresponding backend preview that shows an
approximation of the element's appearance in the TYPO3 page module. The
following sections describe how to achieve that.

A preview renderer is used to facilitate (record) previews in TYPO3. This
class is responsible for generating the preview and the wrapping.

The default preview renderer is `\TYPO3\CMS\Backend\Preview\StandardContentPreviewRenderer`
and handles the Core's built-in content types (field `CType` in table `tt_content`).

## Extend the default preview renderer {#contentpreviewrenderer}

There are two ways to provide previews for your custom content types:
via page [TSconfig](https://docs.typo3.org/permalink/t3coreapi:configurece-preview-pagetsconfig@main) or [event listener](https://docs.typo3.org/permalink/t3coreapi:configurece-preview-eventlistener@main).

### Preview rendering with a Fluid template and page TSconfig {#configurece-preview-pagetsconfig}

<!-- TODO: no Markdown rendering for "versionchanged" -->

A \TYPO3\CMS\Core\Domain\RecordInterface is passed as variable
{record} to the Fluid Template. The fields are not passed as direct
variables anymore. {pi_flexform_transformed} has been replaced by
{record.pi_flexform}. See also Breaking: #92434 - Use Record API in Page Module Preview Rendering.

This is the "integrator" way, no PHP coding is required. Just some page TSconfig
and a Fluid template.

**EXT:my_extension/Configuration/page.tsconfig**

```typoscript
mod.web_layout {
  tt_content {
    preview {
      # Your CType
      example_ctype = EXT:my_extension/Resources/Private/Templates/Preview/MyCType.fluid.html
    }
  }
}

```

For more details see the [TSconfig Reference](https://docs.typo3.org/m/typo3/reference-typoscript/main/en-us/PageTsconfig/Mod/WebLayout.html#pageweblayoutpreview).

In the Fluid template, the following variables are available:

-   The current record as object (`Record`)
    in variable `{record}`

**EXT:my_extension/Resources/Private/Templates/Preview/MyCType.fluid.html**

```html
<h2>{record.header}</h2>
<p>{record.bodytext}</p>
<f:if condition="{record.image}">
  <p>Image UID: {record.image.uid}</p>
</f:if>

<f:variable name="path" value="s_messages/settings" />
<small>{record.pi_flexform.{path}.welcome_header}</small>

Or, the following (same result):

<small>{record.pi_flexform.sheets.s_messages.settings.welcome_header}</small>

```

**Migration**

**EXT:my_extension/Resources/Private/Templates/Preview/MyCType.fluid.html (migration)**

```diff
-<h2>{header}</h2>
+<h2>{record.header}</h2>
-<p>{bodytext}</p>
+<p>{record.bodytext}</p>
-<small>{pi_flexform_transformed.settings.welcome_header}</small>
+<small>{record.pi_flexform.sheets.s_messages.settings.welcome_header}</small>
```

### Event listener {#configurece-preview-eventlistener}

This requires at least some PHP coding, but allows more flexibility in
accessing and processing the content elements properties.

The event `PageContentPreviewRenderingEvent` is being dispatched by the
`StandardContentPreviewRenderer`. You can listen to it with your own
event listener.

Have a look at this [showcase implementation](https://docs.typo3.org/permalink/t3coreapi:pagecontentpreviewrenderingevent@main).

For general information see the chapter on [implementing an event listener](https://docs.typo3.org/permalink/t3coreapi:eventdispatcherimplementation@main).

## Writing a preview renderer {#configurece-preview-preview-renderer}

<!-- TODO: no Markdown rendering for "versionchanged" -->

The @internal class
GridColumnItem has been
updated to work with Record objects.

A custom preview renderer must implement the interface
`\TYPO3\CMS\Backend\Preview\PreviewRendererInterface` which contains
the following API methods:

-   **interface PreviewRendererInterface**

    -   *Fully qualified name:* `\TYPO3\CMS\Backend\Preview\PreviewRendererInterface`

    Interface PreviewRendererInterface

    Contract for classes capable of rendering previews of a given record
    from a table. Responsible for rendering preview header, preview content
    and wrapping of those two values.

    Responsibilities are segmented into three methods, one for each responsibility,
    which is done in order to allow overriding classes to change those parts
    individually without having to replace other parts. Rather than relying on
    implementations to be friendly and divide code into smaller pieces and
    give them (at least) protected visibility, the key methods are instead required
    on the interface directly.

    Callers are then responsible for calling each method and combining/wrapping
    the output appropriately.

    -   **renderPageModulePreviewHeader(\\TYPO3\\CMS\\Backend\\View\\BackendLayout\\Grid\\GridColumnItem $item)**

        Dedicated method for rendering preview header HTML for
        the page module only. Receives the GridColumnItem
        that contains the record for which a preview header
        should be rendered and returned.

        -   *param $item:* the item

        *Returns:* `string`

    -   **renderPageModulePreviewContent(\\TYPO3\\CMS\\Backend\\View\\BackendLayout\\Grid\\GridColumnItem $item)**

        Dedicated method for rendering preview body HTML for
        the page module only. Receives the GridColumnItem
        that contains the record for which a preview should be
        rendered and returned.

        -   *param $item:* the item

        *Returns:* `string`

    -   **renderPageModulePreviewFooter(\\TYPO3\\CMS\\Backend\\View\\BackendLayout\\Grid\\GridColumnItem $item)**

        Render a footer for the record to display in page module below
        the body of the item's preview.

        -   *param $item:* the item

        *Returns:* `string`

    -   **wrapPageModulePreview(string $previewHeader, string $previewContent, \\TYPO3\\CMS\\Backend\\View\\BackendLayout\\Grid\\GridColumnItem $item)**

        Dedicated method for wrapping a preview header and body
        HTML. Receives $item, an instance of GridColumnItem holding
        among other things the record, which can be used to determine
        appropriate wrapping.

        -   *param $previewHeader:* the previewHeader
        -   *param $previewContent:* the previewContent
        -   *param $item:* the item

        *Returns:* `string`

Implementing these methods allows you to control the exact composition of the
preview.

This means assuming your preview renderer returns `<h4>Header</h4>`
from the header render method and `<p>Body</p>` from the preview content
rendering method and your wrapping method does
`return '<div>' . $previewHeader . $previewContent . '</div>';` then the
entire output becomes `<div><h4>Header</h4><p>Body</p></div>` when
combined.

<!-- TODO: no Markdown rendering for "versionchanged" -->

StandardContentPreviewRenderer has been turned
into a stateless, dependency-injected service. It is now declared final
and can no longer be subclassed.

The standard renderer may be composed and its rendering methods delegated to where its output
is desired, as `FormPagePreviewRenderer` demonstrates.

## Configuring the implementation {#configure-ce-preview-configuring-implementation}

Individual preview renderers can be defined by using one of the following
approaches:

1.  Any record

    ```php
    $GLOBALS['TCA'][$table]['ctrl']['previewRenderer']
        = MyVendor\MyExtension\Preview\MyPreviewRenderer::class;
    ```

    This specifies the preview renderer to be used for any record in `$table`.
1.  Table has a type field/attribute

    ```php
    $GLOBALS['TCA'][$table]['types'][$type]['previewRenderer']
        = MyVendor\MyExtension\Preview\MyPreviewRenderer::class;
    ```

    This specifies the preview renderer only for records of type `$type` as
    determined by the [type field](https://docs.typo3.org/m/typo3/reference-tca/main/en-us/Types/Index.html#types) of your table.

Like all other content types, `text`, `textpic`, `textmedia` and
`image` use the standard
`StandardContentPreviewRenderer`. To customize
previews for these elements, use the
[page TSconfig](https://docs.typo3.org/permalink/t3coreapi:configurece-preview-pagetsconfig@main) or
[event listener](https://docs.typo3.org/permalink/t3coreapi:configurece-preview-eventlistener@main) approach described
above (instead of registering type-specific preview renderers as in the past).

> [!NOTE]
> The [recommended location](https://docs.typo3.org/permalink/t3coreapi:extension-configuration-tca@main) is in the
> `ctrl` array in your extension's `Configuration/TCA/$table.php`
> or `Configuration/TCA/Overrides/$table.php` file. The former is used
> when your extension is the one that creates the table, the latter is used
> when you need to override TCA properties of tables added by the Core or
> other extensions.