EDW Mercury Editor

Overrides for Drupal Mercury Editor.

Why

Mercury Editor's tempstore-backed editing session has a few rough edges on multi-editor sites. This module patches them:

• Concurrent-edit detection. Mercury Editor forces the entity's changed timestamp on every form validate, which defeats Drupal core's optimistic-locking check. This module restores it: it swaps in a param converter that keeps the tempstore's original base version on a save request, and a form validation handler that compares it against the live database row, so a user gets "content has been updated by another user" instead of silently overwriting someone else's edit. On a plain read request it does the opposite — a stale tempstore entry is discarded in favor of a newer database version (e.g. saved via the standard edit form, a bulk action, or another user), and a tempstore entry pointing at a deleted entity 404s instead of resurrecting it.
• Published checkbox. The Gin admin theme relocates the "Published" checkbox into markup that only its own page/form templates print. Mercury Editor renders neither, so the checkbox silently disappears from the editor tray; this module puts it back.
• Admin toolbar. Mercury Editor hides the admin toolbar on its editor route by default; this module keeps it visible so editors retain normal site navigation while editing.
• 404/403 chrome. Suppresses Mercury Editor's page template on system error pages, where it doesn't apply.
• Component attributes audit. Warns (log, plus an on-page banner when Twig debug is enabled) when a Layout Paragraphs component's Twig template doesn't forward the attributes variable — Layout Paragraphs/Mercury Editor need it to track the component for drag-reorder, edit and save.

This module was extracted from a project-specific edw_mercury_editor module.

Installation

Add this repository to your project's composer.json and require it:

"repositories": [
    {"type": "vcs", "url": "https://github.com/eaudeweb/edw_mercury_editor.git"}
]

composer require eaudeweb/edw_mercury_editor
drush en edw_mercury_editor

Requirements

The active theme must define two libraries, named after the theme (e.g. for a theme called mytheme: mytheme/edit_screen and mytheme/mercury_editor_preview):

• edit_screen: styles for the editor chrome — toolbar, dialogs and the tray around the preview iframe. Attached to the page--mercury-editor page.
• mercury_editor_preview: styles for the document rendered inside the preview iframe (e.g. rules targeting Layout Paragraphs builder markup like .js-lpb-component). Attached only while mercury_editor.context reports the current request as a preview, since the preview is a separate document from the editor chrome.

If a theme doesn't define these libraries, Drupal silently drops the missing library from the page's asset list — no error, no log entry. The editor and preview just render unstyled until the libraries are added.