---
title: "Add sub data processors"
manual: "Headless Content Blocks"
version: "main"
permalink: "https://docs.typo3.org/permalink/netzbewegung/nb-headless-content-blocks:add-sub-data-processors@main"
source: "Howto/AddSubDataprocessors.rst"
rendered: "2026-09-22T01:10:25+00:00"
---

# Add sub data processors {#add-sub-data-processors}

This guide shows how to add TypoScript-computed data — menus, record lists, plugin output — to a Content Block's `data`.

## The problem it solves {#the-problem-it-solves}

Content Block fields hold editor-managed content. Sometimes the JSON needs computed data: a page tree menu, a list of the latest news records, or anything else a TYPO3 data processor can produce. Instead of writing that in `headless.php`, wire standard data processors via TypoScript.

## Wire a sub data processor {#wire-a-sub-data-processor}

```typoscript
tt_content.vendor_yourcontentblockelement.fields.data.dataProcessing.10 {
    dataProcessing {
        10 = menu
        10 {
            levels = 2
            as = navigation
        }
    }
}
```

What happens:

-   The path addresses the `nb-content-blocks-json` processor (setup position `10` inside `fields.data.dataProcessing`) that the Site Set defines for `lib.contentBlock`.
-   Inside it, `dataProcessing.` works exactly like everywhere else in TypoScript — any registered data processor can be used (`menu`, `database-query`, `files`, your own ...).
-   The `as` name of each sub processor becomes a new key in `data` (here: `data.navigation`).

## Result {#result}

```json
{
    "data": {
        "header": "My header",
        "navigation": [
            { "title": "Home", "link": "/" },
            { "title": "Products", "link": "/products/" }
        ]
    }
}
```

The sub-processor results are merged into `data` after the Content Block fields; the internal keys `data` and `current` are stripped from the result first, so they cannot collide with your fields.

## Notes {#notes}

-   Sub data processors run with the block's `ContentObjectRenderer` context — `field:` references in the sub processor resolve against the block's record.
-   This mechanism is used in production (e.g. dynamic card lists rendered by an additional processor with `as = cards`).
-   Prefer it over [headless.php](https://docs.typo3.org/permalink/netzbewegung/nb-headless-content-blocks:post-process-json-with-headless-php@main) for anything TypoScript already provides.