>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3519344. --> Reported by: [anicoto](https://www.drupal.org/user/3489541) Related to !84 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>Constrain Validator (BookOutlineConstraintValidator) is prevents content editors from saving layout changes in Draft state, even for content that isn't part of any book structure. This issue was fixed on <a href="https://www.drupal.org/project/book/issues/2918537">https://www.drupal.org/project/book/issues/2918537</a> but in did not work.</p> <p>For some reason !empty($value-&gt;book) is not empty, and when editing page Layout with Layout Builder the validation is triggered and I wasn't able to save a new revision in draft.</p> <h4 id="summary-steps-reproduce">Steps to reproduce</h4> <ol> <li>Start with a clean D10 installation with Layout builder and Content moderation workflow enabled on any content type (lets say an Article).</li> <li>Make sure you also have Book module installed and enable for a different content type (lets create a book content type).</li> <li>Create a page (Article) and published the page.</li> <li>Switch to the "Layout" tab and make some changes to the layout.</li> <li>Attempt to save the layout with "Draft" state selected in the moderation control.</li> <li>Note the error message: "You can only change the book outline for the published version of this content. Visit Book outlines page to make changes."</li> <li>Note that no new revision is created despite selecting the Draft state.</li> </ol> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p>A. The Core Book module's constraints validation need to be modified to only apply to content types that are actually part of the book hierarchy or have book functionality enabled. Currently, the validation is triggered for all content with moderation regardless of whether it's actually using book functionality. That should have been solved on a <a href="https://www.drupal.org/project/book/issues/2918537">Cannot save unpublished versions of published content for users without manage book privileges</a></p> <p>B. The Core Book module should be completely deleted or disable if not in use. (I need to validate this again)<br> Reference on -&gt; <a href="https://www.drupal.org/project/book/issues/3519344#comment-16069023">https://www.drupal.org/project/book/issues/3519344#comment-16069023</a></p> <p>C. Create a patch that overrides core Book module constraints validation.<br> <a href="https://git.drupalcode.org/project/book/-/merge_requests/84">MR 84</a></p> <h3 id="summary-remaining-tasks">Remaining tasks</h3> <ol> <li><del>Investigate which specific validation constraint in the Book module is being triggered.</del></li> <li><del>Determine if this is an issue with content moderation in general or specific to Layout Builder.</del></li> <li><del>Create a patch that checks if the entity is actually part of a book hierarchy before applying validation constraints.</del></li> <li>Update the patch to 3.0.x</li> <li>Manual test.</li> <li>Review authomatic tests to ensure the fix doesn't break actual book functionality.</li> </ol> <h3 id="summary-ui-changes">User interface changes</h3> <p>No UI changes required. The goal is to remove the error message for content that isn't part of a book outline.</p> <h3 id="summary-api-changes">API changes</h3> <p>Likely modification to one of the following:<br> - Book module's validation constraints<br> - Entity validation flow when triggered from Layout Builder</p> <h3 id="summary-data-model-changes">Data model changes</h3> <p>No data model changes expected.</p>