ADR for backend data initialization #3734

adamhaeger · 2025-09-23T08:41:19Z

Description

The Frontend Next task force is proposing to load initial app data on the backend.

Related Issue(s)

closes #16309

Summary by CodeRabbit

Documentation
- Added an Architecture Decision Record detailing a move to backend-driven initial data loading and path-based routing (while preserving legacy hash URLs).
- Clarifies the bootstrap payload, routing behavior for deep links, and planned pagination improvements.
- Outlines security, rollout considerations, and acceptance criteria targeting faster initial load (≤2 requests before interactivity) and avoiding redundant refetches for embedded data.
- No user-facing functionality changes yet; this documents upcoming direction.

coderabbitai · 2025-09-23T08:41:26Z

📝 Walkthrough

Walkthrough

Introduces a new ADR documenting a plan to shift initial data loading to the backend, generate bootstrap HTML in HomeController, switch to path-based routing (with legacy hash support), embed AppData and optional InitialInstanceData in the bootstrap payload, and remove frontend-led initial queries and certain components in a later task.

Changes

Cohort / File(s)	Summary
ADR: Backend-driven bootstrap and routing `adr/002-backend-data-initialization.md`	Adds an ADR detailing backend-generated bootstrap HTML, path-based routing, embedding immutable AppData and optional InitialInstanceData, deprecating frontend orchestration (RuleHandler/RuleConfiguration later), rollout plan, security notes, consequences, open questions, and acceptance criteria.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The title succinctly and accurately summarizes the primary change — an ADR proposing backend initialization of app data — and directly matches the added adr/002-backend-data-initialization.md, making it clear to reviewers.
Description Check	✅ Passed	The PR description gives a concise summary and includes a Related Issue (closes #16309), satisfying the template's core context, but it omits the Verification/QA checklist and other template sections (tests, accessibility, docs, labels) that should be completed or explicitly marked when applicable.
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.

✨ Finishing touches

🧪 Generate unit tests

Create PR with unit tests
Post copyable unit tests in a comment
Commit unit tests in branch adr/backend-data-init

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

coderabbitai

Actionable comments posted: 2

🧹 Nitpick comments (5)

adr/002-backend-data-initialization.md (5)
112-121: Use proper headings instead of bold for section titles (fix MD036).

Convert the emphasized lines to markdown headings.
-**Positive**
+### Positive
@@
-**Negative / Trade-offs**
+### Negative / Trade-offs
130-133: Fix ordered list formatting in rollout plan.

Numbers are missing periods/spaces and bold is misapplied.
-1**Route migration:** enable path-based routing; ship redirects for legacy hash URLs; validate deep links.
-2**Delete old providers/effects** and RuleHandler/RuleConfiguration.
-3**Docs & templates:** update app templates and docs; provide migration guide for app owners.
+1. Route migration: enable path-based routing; ship redirects for legacy hash URLs; validate deep links.
+2. Delete old providers/effects and RuleHandler/RuleConfiguration.
+3. Docs & templates: update app templates and docs; provide migration guide for app owners.
94-100: Avoid optional chaining in inline bootstrap and add null checks.

Safer and more compatible DOM access; keeps behavior identical.
-  <script>
-    window.AltinnAppData = JSON.parse(document.getElementById('__appdata').textContent);
-  </script>
-  <script>
-    window.AltinnInitialInstanceData = JSON.parse(
-      document.getElementById('__initialInstanceData')?.textContent || 'null',
-    );
-  </script>
+  <script>
+    (function () {
+      var elApp = document.getElementById('__appdata');
+      if (elApp && elApp.textContent) {
+        window.AltinnAppData = JSON.parse(elApp.textContent);
+      }
+    })();
+  </script>
+  <script>
+    (function () {
+      var elInst = document.getElementById('__initialInstanceData');
+      window.AltinnInitialInstanceData = elInst && elInst.textContent
+        ? JSON.parse(elInst.textContent)
+        : null;
+    })();
+  </script>
78-86: Clarify bootstrap schema versioning.

Add an explicit version to the embedded contract to enable coordinated rollouts.
 - **Bootstrap contract**
+ - Include an explicit `schemaVersion` in both `AppData` and `InitialInstanceData` to support backward/forward compatibility during deploys.
@@
   <script
     id="__appdata"
     type="application/json"
   >
-    { ... AppData ... }
+    { "schemaVersion": "1", ... AppData ... }
   </script>
103-106: Routing ops: add server fallback and proxy-aware handling.

Ensure SPA deep links and asset paths work behind reverse proxies/CDNs.

Serve a single controller/action for all app routes with a catch-all and do not 404 on refresh.

Honor app basePath when generating asset URLs.

Return 404/403 statuses while still serving the app shell for client-side routing to show error pages, as appropriate.

Verify redirects from legacy hash routes are relative and cacheable with short TTL.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 8556c9a and 46a29c2.

📒 Files selected for processing (1)

adr/002-backend-data-initialization.md (1 hunks)

🧰 Additional context used

🪛 markdownlint-cli2 (0.18.1)