fix(ui): printer detail metadata + template preview + paused-bool gap by strausmann · Pull Request #82 · strausmann/Label-Printer-Hub

strausmann · 2026-05-17T21:14:08Z

Summary

Drei UI-Bugs aus Production-Smoke nach Phase 7b.1 + ein zugehöriger Refactor:

Paused-Badge falsch — Drucker mit paused=false zeigte trotzdem "Paused" auf der Homepage. Root cause: Pydantic-Schema paused: bool = False (mit default) → OpenAPI optional-with-default → oapi-codegen Paused *bool, omitempty → Go-Template {{if pointer}} truthy für jeden non-nil-pointer auch &false. Fix: Schema paused: bool (required), Route setzt Wert explizit.
Printer-Detail ohne Metadaten — GET /api/printers/{id} 404te (Endpoint fehlte). Frontend printer.go fetchte nur status/tape/queue. Fix: neuer Backend-Detail-Endpoint + Frontend-Handler-4. errgroup + printer.html Metadata-Block.
Template-Preview "Preview unavailable" — /api/render/preview fehlte. Fix: neuer POST-Endpoint + LabelRenderer-Integration. Returns image/png.
Refactor: Preview-Sample lebt im Template — Commit 3 hatte hardcoded per-app sample-data in der Route. Falsche Verantwortungs-Lokalität — jedes Template muss seine Preview-Daten selbst deklarieren. Neuer optionaler preview_sample Block in der Template-Definition, Route ohne hardcoded-mockup-fallback, 12 Seed-Templates erweitert.

Commits

SHA	Was
`414be23`	`fix(api)`: PrinterRead.paused non-optional
`fe86563`	`feat(api)`: GET /api/printers/{id} + UI-Metadata-Block
`0f93bb3`	`feat(api)`: POST /api/render/preview
`e570896`	`refactor(api)`: preview_sample im Template statt Route-Mockup

Test plan

Backend 685 passed (was 678), 3 skipped, 0 failed
Frontend 4 packages OK, vet clean
ruff + ruff format + mypy clean
oapi-codegen client regeneriert für beide neuen Endpoints
Production-Smoke nach Merge: Homepage Drucker zeigt "Online" (nicht "Paused"); Printer-Detail zeigt Model+Host+Port+Enabled+Paused+Timestamps; Template-Detail-Preview zeigt gerenderte PNG (kein placeholder.svg mehr)

Out-of-scope / Follow-ups

Phase 7e Phase 7e: Template Layout System v2 — semantic qr-first + N-text-lines deklarativ #81 Template Layout System v2 — semantic qr-first + N-text-lines deklarativ, Renderer berechnet Positionen
Mini-PR Doku-SVG-Samples — pure-vector SVG pro Template als git-diff-bare Grundlage für Phase-7e-Brainstorming (Mini-PR folgt direkt)
Latenz-Anzeige im Printer-Detail — last_probe_age_s ist schon drin; eine echte TCP-connect-Latenz-Probe wäre eigenes Feature

Refs #22

…not *bool Pydantic schema 'paused: bool = False' produced OpenAPI 'optional with default' which oapi-codegen translates to 'Paused *bool, omitempty'. Go templates evaluate '{{if pointer}}' as truthy for any non-nil pointer including &false — causing the dashboard to show 'Paused' badge for every printer regardless of actual paused state. Schema is now 'paused: bool' (required). list_printers populates the field explicitly from PrinterState (False when state row absent). Generated client has 'Paused bool'. Regression test added to internal/api/client_test.go (compile-time RED before fix). Refs #22

The detail page previously called only /status, /tape, /queue and had no model/host/enabled/paused information. Production smoke flagged 'keine Metadaten vom Drucker'. Adds the missing detail endpoint plus a Metadata block in printer.html with model, backend, host:port, enabled, paused, created/updated timestamps. Handler now fetches the printer detail in a 4th errgroup goroutine alongside status/tape/queue. Returns 404 when the printer is not registered. Refs #22

The template detail page fell back to /static/preview-placeholder.svg because the backend had no preview endpoint — the frontend client already called POST /api/render/preview?key= and treated any error as 'show placeholder'. Adds the missing route that renders the template with app-appropriate sample data (snipeit/grocy/spoolman/generic) using the existing Phase 4 LabelRenderer. Returns image/png. OpenAPI response declares schema=binary so the completeness gate passes. Frontend template.go already calls RenderPreview — now succeeds end-to-end. Refs #22

…inition Commit 0f93bb3 added the preview endpoint with hardcoded per-app sample data in the route — wrong responsibility lokality. The template itself must declare how it wants to be previewed. TemplateSchema gains an optional preview_sample field. Every seed template (grocy/snipeit/spoolman x 12/18/24 mm + qr-only x 3) gets a preview_sample block with semantically appropriate placeholder values. URLs use RFC 2606 example.com domains. The render_preview route now reads preview_sample directly from template.definition; templates without a preview_sample block return HTTP 422 with a clear error message instead of relying on backend-side mockup data. Refs #22

gemini-code-assist · 2026-05-17T21:14:21Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Dieser Pull Request behebt drei UI-Bugs aus der Produktion und führt ein Refactoring der Template-Vorschau-Logik durch. Der Fokus liegt auf der Korrektur der paused-Status-Anzeige, der Bereitstellung fehlender Metadaten auf der Drucker-Detailseite und der Einführung einer robusten, template-basierten Vorschau-Funktionalität für Etiketten.

Highlights

Paused-Badge Korrektur: Das Pydantic-Schema für den paused-Status wurde von optional (mit Default) auf required umgestellt, um zu verhindern, dass false als truthy Pointer in Go-Templates interpretiert wird.
Printer-Detail-Endpoint: Ein neuer Backend-Endpoint GET /api/printers/{id} wurde hinzugefügt, um vollständige Metadaten im Frontend-Detail-Panel anzuzeigen.
Template-Preview-Funktionalität: Ein neuer POST /api/render/preview-Endpoint wurde implementiert, der Vorlagen-Vorschauen als PNG rendert, basierend auf neuen preview_sample-Blöcken in den Template-Definitionen.
Refactoring der Preview-Daten: Preview-Beispieldaten wurden aus der Route in die jeweiligen Template-Definitionen (YAML) verschoben, um die Verantwortlichkeit zu dezentralisieren.

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codecov · 2026-05-17T21:16:07Z

Codecov Report

❌ Patch coverage is 51.56250% with 31 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.14%. Comparing base (4e74a03) to head (d04d7e8).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
backend/app/api/routes/templates.py	45.45%	30 Missing ⚠️
backend/app/api/routes/printers.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #82      +/-   ##
==========================================
- Coverage   91.98%   91.14%   -0.84%     
==========================================
  Files          70       70              
  Lines        3055     3116      +61     
  Branches      261      263       +2     
==========================================
+ Hits         2810     2840      +30     
- Misses        181      212      +31     
  Partials       64       64

Components	Coverage Δ
Printer Backends (transport)	`87.50% <ø> (ø)`
Printer Models (drivers)	`91.42% <ø> (ø)`
Services	`92.09% <ø> (ø)`
REST API	`87.04% <48.33%> (-4.26%)`	⬇️
Pydantic Schemas	`100.00% <100.00%> (ø)`
Integration Plugins	`100.00% <ø> (ø)`

Files with missing lines	Coverage Δ
backend/app/main.py	`86.27% <100.00%> (+0.16%)`	⬆️
backend/app/schemas/printer.py	`100.00% <100.00%> (ø)`
backend/app/schemas/template.py	`100.00% <ø> (ø)`
backend/app/api/routes/printers.py	`83.60% <80.00%> (-0.16%)`	⬇️
backend/app/api/routes/templates.py	`55.88% <45.45%> (-44.12%)`	⬇️

Flag	Coverage Δ
backend	`91.14% <51.56%> (-0.84%)`	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

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Copilot

Pull request overview

Adds missing backend/frontend support for printer metadata and template preview rendering, while correcting the paused OpenAPI shape so Go templates treat false correctly.

Changes:

Makes PrinterRead.paused required and adds GET /api/printers/{id}.
Adds frontend printer detail metadata fetching/rendering.
Adds backend template preview rendering from per-template preview_sample seed data.

Reviewed changes

Copilot reviewed 26 out of 27 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
`frontend/web/templates/printer.html`	Adds printer metadata block.
`frontend/internal/handlers/printer.go`	Fetches printer metadata alongside status/tape/queue.
`frontend/internal/handlers/printer_test.go`	Adds printer metadata regression coverage.
`frontend/internal/handlers/dashboard_test.go`	Adds paused badge regression test.
`frontend/internal/api/openapi.snapshot.json`	Updates printer schema and adds printer detail route snapshot.
`frontend/internal/api/client.go`	Adds printer detail API wrapper.
`frontend/internal/api/client.gen.go`	Regenerates printer detail client and `Paused bool`.
`frontend/internal/api/client_test.go`	Verifies `paused=false` decodes as plain bool false.
`backend/tests/unit/api/test_templates_routes.py`	Adds preview endpoint and seed preview tests.
`backend/tests/unit/api/test_printers_routes.py`	Adds printer detail endpoint tests.
`backend/app/seed/templates/*.yaml`	Adds preview samples to seed templates.
`backend/app/schemas/template.py`	Adds optional `preview_sample` schema field.
`backend/app/schemas/printer.py`	Makes `paused` required.
`backend/app/main.py`	Registers render router.
`backend/app/api/routes/templates.py`	Adds `/api/render/preview`.
`backend/app/api/routes/printers.py`	Adds `/api/printers/{id}` detail endpoint.

Files not reviewed (1)

frontend/internal/api/client.gen.go: Language not supported

gemini-code-assist

Code Review

This pull request implements a new printer detail endpoint and a template preview rendering service, alongside a fix for a bug where the "Paused" badge was incorrectly displayed on the dashboard. The printer detail page now includes a metadata block. Review feedback identifies opportunities to simplify template schema reconstruction and optimize LabelRenderer instantiation. Crucially, it is noted that synchronous rendering operations should be wrapped in asyncio.to_thread to avoid blocking the FastAPI event loop, adhering to the project's performance guidelines.

Lines 140 and 149 of render_preview passed the raw user-supplied query parameter `key` to _log.warning. Replace with `template_row.key`, which is the sanitised value read back from the database after the 404 check, so no user-controlled data reaches the log calls. Fixes CodeQL alert CWE-117 (log injection) in both branches. Refs #22

Printer.connection is dict[str, object] — USB printers store {interface: "usb"} with no host/port. The metadata block now wraps the host:port <dd> in a conditional that checks both keys exist; USB printers fall through to an "Interface" row showing the interface value. The stub printer template in base.go is updated to render real metadata fields so handler tests can assert on model, host:port, and the USB badge. A new TestPrinterDetailUSBConnection test covers the USB code path and guards against regression. Refs #22

…ient The render_preview endpoint existed in the backend since commit 0f93bb3 but was absent from the OpenAPI snapshot, so the generated client had no typed method for it. Add the path to openapi.snapshot.json and re-run `make gen-client` (oapi-codegen v2.7.0). The generated client.gen.go now exposes RenderPreviewApiRenderPreviewPost on both the Client and ClientWithResponses types. The hand-written HubClient.RenderPreview in client.go is kept because the endpoint returns binary image/png — the generated method returns a raw *http.Response which the wrapper converts to []byte with proper error handling. Refs #22

Two MEDIUM perf findings in render_preview: 1. LabelRenderer was instantiated on every POST /api/render/preview request, paying repeated font-loading cost. The lifespan now creates a single shared instance stored in app.state.label_renderer (also passed to PrintService so there is only one renderer in the process). The route reads it from app.state and falls back to a fresh instance for tests that don't wire the full lifespan. 2. image.save(buf, "PNG") is a synchronous CPU-bound call that blocked the event loop. The render + encode is now wrapped in a private _render_and_encode() helper executed via asyncio.to_thread so the loop stays free during image processing. Refs #22

…nger regression tests Address remaining MEDIUM Bot-Review findings on PR #82: - Add _validate_preview_sample_fields helper that rejects (422) templates whose preview_sample is missing fields referenced by their elements, instead of silently rendering empty output (Copilot finding). - Drop the redundant 'strip preview_sample from schema_dict' since TemplateSchema now includes preview_sample as an optional field (Copilot + Gemini finding). Comment removed. - TemplateSchema.preview_sample sequence type changed from list[str] to tuple[str, ...] so that the frozen=True schema is deeply immutable — pydantic frozen prevents attribute reassignment but does NOT freeze nested mutable containers (Copilot finding). - dashboard_test now asserts printer-grid wrapper presence + <nil> absence — the prior assertions would have passed even if Paused were still rendered as a *bool pointer (Copilot finding on test quality). - printer_test now asserts the model, host:port, and data-enabled attribute round-trip through the rendered body — confirming the new metadata block actually surfaces the printer data, not just the container div (Copilot finding on test quality). Refs #22

## 0.6.0 (2026-05-18) * docs(api): address PR #79 bot-review — privacy sanitise + protocol self + consistency fixes ([61602d0](61602d0)), closes [#79](#79) [#22](#22) * docs(api): pure-vector SVG samples for all 12 seed templates (#83) ([a066dde](a066dde)), closes [#83](#83) [#81](#81) [#22](#22) * docs(phase-7b): foundation design spec — init-robustness + health-split + pangolin-bypass (#74) ([c5a7964](c5a7964)), closes [#74](#74) [fosrl/pangolin#3099](fosrl/pangolin#3099) [#22](#22) [#22](#22) * docs(phase-7d): foundation design — print API + QR tab + hangar plugin (#79) ([cdaedeb](cdaedeb)), closes [#79](#79) [strausmann/hangar#63](https://github.com/strausmann/hangar/issues/63) [#22](#22) * fix: 3 production bugs from local smoke-test + dev/ folder ([c0fc903](c0fc903)), closes [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) * fix: Phase 6b code-cleanup — 6 audit findings + plugin pattern wired ([f77aa44](f77aa44)), closes [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) [#67](#67) * fix(api): Phase 7b.1 — upsert name-collision + /readiness proxy gap (#77) ([4e74a03](4e74a03)), closes [#77](#77) [#76](#76) [#22](#22) [#76](#76) [#22](#22) [#77](#77) [#1](#1) [#76](#76) [#22](#22) * fix(ui): printer detail metadata + template preview + paused-bool gap (#82) ([52bab83](52bab83)), closes [#82](#82) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) * feat(api): Phase 7b foundation — init, datetime-TZ, /readiness, status cache, proxy widening (#75) ([784decc](784decc)), closes [#75](#75) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [#22](#22) [HI#priority](https://github.com/HI/issues/priority) [#75](#75) [#22](#22) * feat(ui): proxy legacy /print to backend (restores First-Print smoke curl) (#84) ([8ef36ed](8ef36ed)), closes [#84](#84) [#22](#22) [#22](#22) [#84](#84) [#22](#22) [skip ci]

strausmann added 4 commits May 17, 2026 20:48

Copilot AI review requested due to automatic review settings May 17, 2026 21:14

Copilot started reviewing on behalf of strausmann May 17, 2026 21:14 View session

github-advanced-security AI found potential problems May 17, 2026

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Comment thread backend/app/api/routes/templates.py Fixed

Comment thread backend/app/api/routes/templates.py Fixed

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strausmann mentioned this pull request May 17, 2026

docs(api): pure-vector SVG samples for all 12 seed templates #83

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4 tasks

strausmann added 5 commits May 17, 2026 21:57

strausmann merged commit 52bab83 into main May 17, 2026
18 of 19 checks passed

strausmann deleted the fix/ui-printer-template-paused-metadata branch May 17, 2026 22:57

This was referenced May 17, 2026

docs: master tracking issue — overall implementation phases #22

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Bug: Template-Detail-Page preview-PNG wird durch html/template escaped (#ZgotmplZ) #87

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fix(ui): printer detail metadata + template preview + paused-bool gap#82

fix(ui): printer detail metadata + template preview + paused-bool gap#82
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strausmann commented May 17, 2026

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strausmann commented May 17, 2026

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