---
title: "Breaking: #101392 - getIdentifier() and setIdentifier() from AbstractFile removed"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:breaking-101392-1742741515"
source: "Changelog/14.0/Breaking-101392-GetIdentifierAndSetIdentifierFromAbstractFileRemoved.rst"
typo3-version: "14.0"
typo3-major: 14
type: "breaking"
issue: 101392
forge: "https://forge.typo3.org/issues/101392"
tags: ["PHP-API", "NotScanned", "ext:core"]
rendered: "2026-09-20T18:31:11+00:00"
---

# Breaking: #101392 - getIdentifier() and setIdentifier() from AbstractFile removed {#breaking-101392-1742741515}

See [forge#101392](https://forge.typo3.org/issues/101392)

## Description {#description}

When using the PHP API of the **File Abstraction Layer (FAL)**, several classes
are involved in representing file objects.

In addition to the
`FileInterface`, there is also the
`AbstractFile` class, from which most file-
related classes inherit.

To ensure stricter type consistency, the abstract class no longer implements
the methods `getIdentifier()` and `setIdentifier()`. Implementing
these methods is now the responsibility of each subclass.

The methods are now implemented in the respective concrete classes inheriting
from `AbstractFile`.

## Impact {#impact}

In the unlikely case that the TYPO3 File Abstraction Layer has been extended
with custom PHP classes derived from
`AbstractFile`, this change will
cause a fatal PHP error, as the new abstract methods `getIdentifier()` and
`setIdentifier()` must be implemented by the subclass.

## Affected installations {#affected-installations}

TYPO3 installations that include custom code extending the File Abstraction
Layer are affected. Such cases are considered highly uncommon.

## Migration {#migration}

Implement the two methods `getIdentifier()` and `setIdentifier()` in
any custom file class extending
`AbstractFile`.

This can also be implemented in older TYPO3 versions to ensure forward
compatibility with TYPO3 v14 and later.