---
title: "Breaking: #102151 - XML prologue always added in flexArray2Xml()"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:breaking-102151-1697111006"
source: "Changelog/13.0/Breaking-102151-XMLPrologueAlwaysAddedInFlexArray2Xml.rst"
modified: "2026-09-15T10:46:36+00:00"
---

# Breaking: #102151 - XML prologue always added in flexArray2Xml()

See [forge#102151](https://forge.typo3.org/issues/102151)

## Description

The second argument `$addPrologue = false` on
`\TYPO3\CMS\Core\Configuration\FlexForm\FlexFormTools->flexArray2Xml()`
has been dropped: When imploding a FlexForm array to an XML string using
this method, the "XML prologue" is always added.

## Impact

This should have no impact for consumers of this method. The counterpart method
`\TYPO3\CMS\Core\Utility\GeneralUtility::xml2array()` happily deals with this.

## Affected installations

Instances with extensions using `FlexFormTools->flexArray2Xml()` can drop
the second argument. The extension scanner will find usages with a weak match.

Since this is a detail method of the TYPO3 Core FlexForm handling, not often
handled by extensions themselves, few instances will be affected in the first place.

## Migration

No data migration needed, PHP consumers should drop the second argument
when calling the method.