TYPO3 Core

Based on my note https://forge.typo3.org/issues/86141#note-5 when analyzing the behavior

TL;DR¶

When skimming over the examples below, focus and compare the values in l10n_parent and realize that l10n_source is optional.

Usage¶

Localizations can be created using the graphical backend interface (e.g. page module) or by invoking direct commands to DataHandler [1]. Thus even if the page module is only valid for tt_content records, it does not prevent records from being translated or localized explicitly. That's why this analysis used element instead of tt_conent a pointer to a database table holding relevant records.

Terminology¶

Connected Mode¶

When translating elements, each element is bound to it's relative ancestor. This results into a chain (that can be used for language fallbacks etc.).
The following example illustrates that, l10n_parent always points to the initial record in default language, l10n_source points to it's relative translation ancestor - that's the record a new translation is based on. All records are connected in a chain.

+ element:1 - English (Default)           - language:0, l10n_parent=0, l10n_source=0
+ element:2 - French Translation          - language:1, l10n_parent=1, l10n_source=1
+ element:3 - Franco-Canadian Translation - language:2, l10n_parent=1, l10n_source=2

Free Mode¶

When localizing elements in free-mode, the previously mentioned translation chain is broken up, thus "free-mode localizaion elements" are in a specific language, but are not related to any relative ancestor and thus are idependent. The following example uses element:3 as "free-mode localization", l10n_parent is set to 0, but l10n_source still points to it's relative localization ancestor (just as information, not as a strict relation in like a "composition" [2] would have been).

+ element:1 - English (Default)           - language:0, l10n_parent=0, l10n_source=0
+ element:2 - French Translation          - language:1, l10n_parent=1, l10n_source=1
+ element:3 - Franco-Canadian Translation - language:2, l10n_parent=0, l10n_source=2

The Challenge¶

Translation from existing localization¶

It is possible, to create a new localization directly, that does not have a record in default language - or as alternative start a translation based on a "free-mode localization element".
The example shows, that the "English (Default)" record is now missing - the translation chain should(!) start with "French Translation" as first chain link. Since no record in default language s involved l10n_parent stay empty with 0, only l10n_source point to their according relative ancestor records.

+ element:2 - French Translation          - language:1, l10n_parent=0, l10n_source=1  # <- translation chain or free-mode localization?!
+ element:3 - Franco-Canadian Translation - language:2, l10n_parent=0, l10n_source=2  # <- translation chain or free-mode localization?!

When comparing the "Franco-Canadian Translation" here to the one shown in the "Free Mode" section, it cannot be distinguished anymore, whether the record is part of a "translation chain" or has been created as "free-mode localization".

The information in l10n_source is not mandatory¶

Besides that, the information stored in the l10n_source field is optional and has to be configured in the control section of $TCA using the translationSource property. Thus, that information might not be available at all. The following examples show persisted results without having the l10n_source information.

Connected Mode without l10n_source¶

+ element:1 - English (Default)           - language:0, l10n_parent=0
+ element:2 - French Translation          - language:1, l10n_parent=1  # <- part of a translation chain, which one?!
+ element:3 - Franco-Canadian Translation - language:2, l10n_parent=1  # <- part of a translation chain, which one?!

It is not possible anymore to determine at all, whether a record is part of a translation chain - since the relative ancestor is missing.

Free Mode without l10n_source¶

+ element:1 - English (Default)           - language:0, l10n_parent=0
+ element:2 - French Translation          - language:1, l10n_parent=1  # <- part of a translation chain, which one?!
+ element:3 - Franco-Canadian Translation - language:2, l10n_parent=0  # <- translation chain or free-mode localization?!

It is (like in section "Translation from existing localization") not possible to distinguish between "connected translations" and "free-mode localizations".

References¶

[1]: DataHandler commands "localize" and "copyToLanguage": https://docs.typo3.org/typo3cms/CoreApiReference/ApiOverview/Typo3CoreEngine/Database/Index.html#command-keywords-and-values
[2]: Association, Aggregation, Composition in UML: https://www.visual-paradigm.com/guide/uml-unified-modeling-language/uml-aggregation-vs-composition/