Untranslated translatable fields on translations of nodes are not marked for Language of Parts

Created on 25 May 2023, about 1 year ago

Updated 31 May 2023, about 1 year ago

Problem/Motivation

If content translation has been enabled for a website, and a field within a content type has been designated as translatable, then when a node in the site's primary language gets a new translation, the translatable fields in the new translation are pre-populated with the original contents in the website's language. Until such time as the contents of the field are translated, I would expect that content to be surrounded with a tag that marks its language as not being in the page's language. However, as of Drupal 10.0.9, the content is not being so marked.

Steps to reproduce

As an administrator:
1. Create an English-language website
2. Add Spanish as a content translation language
3. Make the Article content type translatable and hide untranslatable fields from translation edits
4. Make all the existing fields translatable
7. Add Content > Article
8. Enter a title "English page with translatable content"
9. Enter body text "This content is translatable."
10. Leave the page language as English
11. Save/publish
12. Click the Translate tab
13. Replace the title with "Página en inglés con contenido traducible"
14. Do not edit the body field
15. Save/publish
17. Right-click the words "This content is translatable."

Expected result:
<div class="field__item" lang="en"><p>This content is translatable.</p></div>

Actual result:
<div class="field__item"><p>This content is translatable.</p></div>

Proposed resolution

Option 1:
Assume that if an editor has edited the field, that the contents of the field are now translated. While this is a risky assumption, at least formattable text fields can take appropriate within-field language attributes. This option is probably not appropriate for any plain-text fields, since those cannot take in-field language attributes.

If the translatable field on the translated instance has not been edited before saving, then on rendering the translated instance, wrap the field in a language attribute for the original node language.
If the translatable field on the translated instance has been edited before saving, then on rendering the translated instance, do not wrap the field in a language attribute for the original node language.

Option 2:
Require the editor to confirm whether they have translated each edited field on the translated instance.

Whenever an editor types into a translatable field on a translated instance, add a checkbox below the field "This field has been translated".
If the checkbox has not been checked before saving, then on rendering the translated instance, wrap the field in a language attribute for the original node language.
If the checkbox has been checked before saving, then on rendering the translated instance, do not wrap the field in a language attribute for the original node language.