>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3588342. --> Reported by: [joncjordan](https://www.drupal.org/user/855992) Related to !68 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p><code>AltTextRules</code> validation behaves correctly when editing or creating media on dedicated media routes (e.g. <code>/media/add/{type}</code>, <code>/media/{id}/edit</code>). On content types that use a Media reference field with the <strong>Media Library</strong> widget, users observe no validation (or validation appears inconsistent), even though the same media type and image field are subject to alt text rules when saved from the media UI.</p> <p>This creates an inconsistent editorial experience and can allow media with invalid alt text to be attached to nodes without surfacing the same errors that appear on the media form.</p> <h4 id="summary-steps-reproduce">Steps to reproduce</h4> <ol> <li>Enable Alt Text Validation and configure rules (e.g. rules that clearly fail on trivial alt text).</li> <li>Confirm validation on Media UI: <ol> <li>Visit <code>/media/add/image</code> (or your image media bundle), set alt text that violates a rule, save &rarr; validation error appears (expected).</li> <li>Edit an existing item at <code>/media/{mid}/edit</code>, violate a rule, save &rarr; error appears (expected).</li> </ol> </li> <li>On a content type (e.g. Article), use a Media field configured with the Media Library widget.</li> <li>Create new media from the library or attach media in a way that would previously only be validated on the media form. Use alt text that should fail rules where the UI allows editing alt.</li> <li>Click "Save and select" or "Save and insert" </li></ol> <p><strong>Actual result</strong>: No alt text validation (or no validation in the same way as /media/...).</p> <p><strong>Expected result</strong>: The same (or clearly documented equivalent) alt text rules should apply when media is created or edited in the Media Library context, and/or when saving content that references media whose alt rules matter for accessibility.</p> <h3>How the issue was introduced</h3> <p><strong>Validator exits early on &ldquo;AJAX&rdquo; requests</strong><br> <code>AltTextRulesConstraintValidator::validate()</code> returns immediately when <code>HTTP_X-Requested-With: XMLHttpRequest</code> is present (see <code>isAjaxRequest()</code>). Media Library flows often use Drupal AJAX; media saves initiated from those flows may skip validation entirely even when the media entity is the one being validated.</p> <p>This issue was first introduced here:</p> <ul> <li><a href="https://www.drupal.org/project/alt_text_validation/issues/3541613">https://www.drupal.org/project/alt_text_validation/issues/3541613</a></li> <li><a href="https://git.drupalcode.org/project/alt_text_validation/-/merge_requests/61/diffs#0cc72a029a23c561517de2119e24327e598b539e_76_75">https://git.drupalcode.org/project/alt_text_validation/-/merge_requests/61/diffs#0cc72a029a23c561517de2119e24327e598b539e_76_75</a></li> </ul> <p><a href="https://www.drupal.org/project/alt_text_validation/issues/3541613">#3541613</a> (&ldquo;Clicking the Add paragraph button triggers validation&rdquo;) showed that AJAX-driven partial updates on entity forms (paragraphs &ldquo;Add&rdquo;, image field widgets, etc.) were causing full entity validation, so AltTextRules ran at the wrong time and surfaced errors/warnings above unrelated UI.</p> <p>The issue was fixed in <a href="https://git.drupalcode.org/project/alt_text_validation/-/merge_requests/61">!61</a> by detecting AJAX and bypassing validation in <code>AltTextRulesConstraintValidator::validate()</code>. It was noted that <code>#limit_validation_errors</code> is not available from a field constraint, so a form-level fix was not practical for this module as written. That approach correctly stops spurious validation on intermediate AJAX requests on large entity forms.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p><strong>Narrow the AJAX bypass</strong><br> Replace the blanket &ldquo;skip on every XHR&rdquo; rule with a narrower condition that still matches the original failure mode, for example:</p> <ul> <li>Only skip when the entity being validated is of a type that exhibited the bug, starting with node (and optionally other types added via config if the same problem appears on block_content, etc.).</li> <li>Do not skip when the entity is media (or whatever types must enforce alt on AJAX saves).</li> <li>Check route name: if the current route is something like <code>media_library.ui</code> (modal) or a deliberate media save endpoint, don't skip. If it's a generic entity form with AJAX, skip. </li></ul> <p>But there could be other solutions I'm no aware of. </p>