## Summary Language scope should only be usable when the site has more than one language. On a single-language site (Language module off, or Language module on with only one language), treat the plugin as unavailable — the same way a disabled scope is skipped — instead of showing a stub widget that silently drops stored values on save. Found while reviewing #3586405 / MR !258. Pre-existing; not caused by the scope field storage change. ## Problem `AiContextScopeLanguage::buildValueForm()` special-cases `count($values) <= 1`: it hides the checkboxes and shows “This site has only one language … so language scoping is ignored.” That is only a form-widget stub. The plugin stays enabled, so: - The Languages details box still appears on the item form. - Agent subscription forms can still expose language. - Selection / hard filters can still use stored `language` values (`AiContextScopeResolver` skips only `!$plugin->isEnabled()`). - Item form submit rebuilds the whole scope from posted values (`AiContextItemForm` → `setScope($processed_scope)`). Language posts nothing, so `extractFormValues()` returns `[]` and any stored language scope (API, recipe, Default Content, or an import from a multilingual site) is removed on the first UI save. “Language module disabled” is the same path today. Core still has one language (`en`); there is no hard unavailable check. Language scope means multilingual targeting. With one language it has nothing to match against and should not be assignable. ## Proposed approach Treat “fewer than two languages” as unavailable, using the same skip paths as a disabled scope (`isEnabled() === FALSE` in the item form, subscription form, resolver, and listing pills). Suggested implementation (open to a cleaner hook): - Add something like `isAvailable()` on the language plugin (or fold it into `isEnabled()` so settings + runtime stay one source of truth). - Unavailable when `count($this->languageManager->getLanguages()) <= 1`. - Hide Languages on the item form and agent subscription form (no stub details box). - Skip `language` in selection / hard filters and listing pills. - On `/admin/config/ai/context/settings/scope`, hide or disable the Language card unless a second language exists. - Leave stored `language` rows in the field. Recipes that ship `language: en` should no-op on a single-language site. Do not rely on form save to strip them. When a second language is added, the plugin becomes available again and existing stored values start applying. ## Out of scope - #3586405 field-type / Default Content storage work - Changing language detection or translation fallback - Folding language scope into entity langcode - `AiContextScopeItem::generateSampleValue()` (separate DX follow-up) ## Acceptance criteria - [ ] On a site with one language, Languages does not appear on the context item form or agent subscription form - [ ] On a site with one language, stored `language` values do not filter or score items - [ ] Saving an item on a single-language site does not need to be the mechanism that “clears” language scope; selection already ignores it - [ ] Adding a second language makes the plugin available; existing stored values apply without a re-save - [ ] Removing the last extra language makes the plugin unavailable again - [ ] Docs (`docs/features/scopes.md`, multilingual notes) state that language scope requires more than one language - [ ] Kernel/functional coverage for the one-language vs two-language split (form + selection) ## Testing instructions 1. Single-language site (Language module off, or on with only English): - Item add/edit form has no Languages widget. - Create an item via `setScope(['language' => ['en'], 'use_case' => ['working_with_text']])` or recipe YAML. Save through the UI. Use Case remains. Language does not affect listing or selection. 2. Add Spanish. Edit the same item: Languages checkboxes appear. Selection can filter by language. 3. Delete Spanish so only English remains. Languages disappears again; stored values are ignored. ## Related - #3586405 — scope field storage (discovery only; do not fix here) - #3586196 — scope model discussion ## AI usage - [x] AI assisted issue