Renderlet editable never sends parentDocumentId — useParams is empty inside the document editor iframe

[Maxara]

Affected Version

2026.2

Affected capability

Documents

Steps to reproduce

1. Create an area brick with a renderlet editable whose controller reads the host document, e.g.:

   public function renderAction(Request $request): Response
   {
       $document = $request->attributes->get('contentDocument'); // null in Studio
       // pass $document to a template that requires it, e.g. a non-nullable Twig function argument
   }

2. Drop a data object onto the renderlet in the Studio document editor.
3. Observe GET /pimcore-studio/api/documents/renderlet/render?... — no parentDocumentId in the query string → controller receives no contentDocument → 500 if the template requires the document.
4. Supplying parentDocumentId=<docId> on the same request (e.g. via the config workaround below) makes it succeed, since RenderletService::getAttributes() then calls ActionRenderer::addDocumentAttributes() which sets contentDocument.

Actual Behavior

parentDocumentId is missing from the request. Renderlet controllers that read $request->attributes->get('contentDocument') get null. Templates that need the host document (design/theming resolution, site context) throw, and the editable shows "error-loading-renderlet" with a 500.

Expected Behavior

The renderlet render request includes the id of the document being edited as parentDocumentId, matching what the Classic UI does (ExtJS sends pimcore_parentDocument with every renderlet request, and the admin RenderletController sets contentDocument from it). Note that the host document is not part of the documented renderlet controller contract (Renderlet docs only document id, type, subtype and custom config params) — but parentDocumentId exists as a dedicated parameter in the Studio API (RenderletParameter), Classic editmode has always provided the document, and frontend rendering provides it too, so the Studio editor is the only context where it's missing.

[Maxara]

Root Cause

File: assets/js/src/core/modules/element/dynamic-types/definitions/document/editable/components/renderlet-editable/renderlet-content.tsx

import { useParams } from 'react-router-dom'
// ...
const { id } = useParams<{ id: string }>()          // always {} inside the editor iframe
const documentId = !isNil(id) ? parseInt(id) : undefined
// ...
parentDocumentId: documentId ?? undefined,           // therefore always undefined

The iframe app (.../tabs/edit/iframe-app/iframe-app-view.tsx) mounts editables without any router, wrapped in DocumentProvider:

<DocumentProvider id={ documentId }>   // documentId from ?documentId= query param
  <EditablesLoader editableDefinitions={ editableDefinitions } />
</DocumentProvider>

Sibling code already does it correctly — the areablock hook:

File: assets/js/src/core/modules/element/dynamic-types/definitions/document/editable/components/areablock-editable/hooks/use-areablock-editable.ts

import { DocumentContext } from '@Pimcore/modules/document/document-provider'
// ...
const { id: documentId } = useContext(DocumentContext)

Suggested Fix

In renderlet-content.tsx, replace useParams with the document context:

import { useContext } from 'react'
import { DocumentContext } from '@Pimcore/modules/document/document-provider'
// ...
const { id: contextDocumentId } = useContext(DocumentContext)
const documentId = contextDocumentId > 0 ? contextDocumentId : undefined