>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3588091. --> Reported by: [mably](https://www.drupal.org/user/3375160) Related to !34 !32 >>> <h3>Problem / Motivation</h3> <p><code>domain_config_ui</code> supports per-domain configuration overrides through <code>ConfigFormBase</code> forms (<code>system.site</code>, etc.). It does <strong>not</strong> currently surface those overrides on <code>EntityForm</code>-based config-entity admin flows (block, view modes, search pages, views, &hellip;):</p> <ol> <li>The parent module's <code>form_alter</code> only injects the "Enable domain configuration" toggle on <code>ConfigFormBase</code> and <code>ConfigTranslationFormBase</code>; <code>EntityForm</code>-based edit pages never see it.</li> <li>Drupal core's <code>AdminPathConfigEntityConverter</code> loads config entities <em>override-free</em> on every admin route, so the edit form for a domain-overridden block renders the base values.</li> <li><code>ConfigEntityListBuilder::load()</code> calls <code>loadMultipleOverrideFree()</code> on the entity storage handler, so admin list pages render base values too. The same call path bites <code>BlockListBuilder::submitForm()</code>, where saving region or weight on a block whose label is overridden silently overwrote the existing override via the diff bridge in <code>DomainConfigOverrideEditable::save()</code>.</li> </ol> <h3>Proposed resolution</h3> <p>A new experimental submodule <code>domain_config_entity_ui</code> in this project, layering five coordinated pieces on top of <code>domain_config_ui</code>:</p> <ul> <li><code>DomainAwareConfigEntityStorageTrait</code> overrides <code>doLoadMultiple()</code> to fold the active domain's override on top of the override-free read path. Regular loads (saves, runtime, drush, &hellip;) flow through unchanged: the trait short-circuits when <code>$this-&amp;gt;overrideFree</code> is FALSE.</li> <li><code>DomainAwareConfigEntityStorageInterface</code> is an empty marker. The form_alter and ParamConverter both gate on <code>$storage instanceof DomainAwareConfigEntityStorageInterface</code> &mdash; capability discovery is runtime introspection rather than a hardcoded entity-type list.</li> <li><code>DomainAwareConfigEntityStorage</code> is a thin shell that uses the trait, implements the interface, and extends core's <code>ConfigEntityStorage</code>. <code>DomainAwareSwapRegistry::computeSwaps()</code> auto-discovers every config entity type whose default <code>storage_class</code> is <code>ConfigEntityStorage</code> (block, view modes, search pages, views, &hellip;) and registers a swap to this class. <code>hook_entity_type_alter()</code> applies it.</li> <li><code>DomainConfigEntityUiFormHooks::formAlter()</code> exposes the parent module's "Enable domain configuration" toggle on EntityForm-based config-entity edit pages, gated on the marker interface so types we do not cover never see the toggle.</li> <li><code>DomainOverrideConfigEntityConverter</code> runs at higher priority than core's <code>AdminPathConfigEntityConverter</code>. Same capability gate; loads override-merged for registered configs on the active domain, otherwise defers to core's behavior.</li> </ul> <h3>Two-stage opt-in</h3> <ol> <li><strong>Installing the submodule</strong> &mdash; <code>lifecycle: experimental</code> plus Drupal's install confirmation prompt is the gross gate.</li> <li><strong>Per-entity-type checkboxes</strong> on a SettingsForm at <code>/admin/config/domain/config-entity-ui</code>. Default install: empty. The user explicitly checks each entity type they want covered. The settings subscriber clears entity-type definitions on save so the swap takes effect on the next request without <code>drush cr</code>. The form opens with a yellow warning that only <code>block</code> has been validated end-to-end; the other auto-discovered types are best-effort and should be tested on a non-production environment first.</li> </ol> <h3>Extensibility &mdash; <code>hook_domain_config_entity_ui_swaps_alter</code></h3> <p>Documented in <code>domain_config_entity_ui.api.php</code>. Contrib modules ship a sibling <code>DomainAware*Storage</code> subclass (extending the entity type's existing storage handler, using the trait, implementing the interface) and register it via the alter hook for entity types whose default <code>storage_class</code> is a custom subclass (<code>image_style</code> &rarr; <code>ImageStyleStorage</code>, <code>user_role</code> &rarr; <code>RoleStorage</code>, <code>menu</code> &rarr; <code>MenuStorage</code>, &hellip;). Modules can also REMOVE auto-discovered entries from <code>$swaps</code> to opt a vanilla-storage entity type out of coverage entirely.</p> <h3>Tests</h3> <p>Kernel (3 files, 11 tests / 49 assertions):</p> <ul> <li><code>DomainAwareConfigEntityStorageTest</code> &mdash; storage swap on install, override-merged read on registered configs, BlockListBuilder save flow regression, mid-request override re-read, non-curated entity type stays on its own handler, disabling un-checks the swap.</li> <li><code>DomainOverrideConfigEntityConverterTest</code> &mdash; converter capability gate (registered &rarr; override-merged, unregistered &rarr; defer to parent).</li> <li><code>DomainAwareSwapRegistryAlterTest</code> &mdash; alter-registered entries surface in the registry, coexist with auto-discovery, strict-equality guard rejects mismatched contrib registrations.</li> </ul> <p>Functional (<code>DomainConfigEntityUiToggleTest</code>):</p> <ul> <li>Toggle present on Configure block; absent on Place block; absent on uncovered <code>user_role</code>.</li> <li>SettingsForm flips coverage on the next request (full UX path: empty &rarr; check block &rarr; toggle appears).</li> <li>Save round-trip: toggle &rarr; register &rarr; edit label &rarr; save &rarr; per-domain override holds the new value, base config untouched, form re-renders override-merged. Skipped on environments where the parent diff bridge is missing (<code>property_exists($baseData)</code> probe).</li> </ul> <h3>Module info</h3> <ul> <li>name: Domain Configuration Entity UI</li> <li>package: Domain</li> <li>lifecycle: experimental, lifecycle_link points at this issue</li> <li>core_version_requirement: ^10.3 || ^11 (uses <code>\Drupal\Core\Form\ConfigTarget</code> from 10.3)</li> <li>configure: <code>domain_config_entity_ui.settings_form</code> (Configure link on the Modules admin page)</li> <li>menu link: under <em>Configuration &rarr; Domain &rarr; Domain config entity types</em></li> <li>permission: <code>administer domain config entity ui</code> for the SettingsForm</li> <li>dependencies: <code>domain:domain_config_ui</code> (no hard <code>block</code> dep &mdash; runtime is generic)</li> </ul> <h3>Related</h3> <ul> <li><a href="https://www.drupal.org/project/domain/issues/3587744">domain #3587744</a> &mdash; parent issue, write-side correctness in <code>domain_config</code>; merged.</li> <li><a href="https://www.drupal.org/project/domain/issues/3588057">#3588057</a> / <a href="https://www.drupal.org/project/domain_extras/issues/3588108">#3588108</a> &mdash; parallel "menu plugin manager cache leaks across domains" pair.</li> </ul>