fix(signage): stop playback leaks, restarts and stalls

[MrYuion]

Over days of looping, the media player leaked blob URLs, restarted items, cut items short and could hold the screen:

• No ngOnDestroy, so up to 5 blob URLs leaked per takeover or template change.
• Any playlist change restarted the current item after a blank gap.
• A fatal error from a preloaded plugin cut the active image short.
• Retries counted as plays in the metrics.
• iframe.src comparisons failed after URL normalisation, so preloaded webpages loaded twice.
• A lone play-through plugin played once, then stopped.
• A single-pass takeover with one webpage or plugin never ended.

Changes

• URL cleanup: ngOnDestroy revokes item URLs, and URLs that resolve late are revoked.
• Playlist changes: the current item keeps its URL and output when it is still in the new list.
• Plugin errors: handled only for the active plugin on its own output.
• Metrics: emitted on a real advance only. Debug "previous" and playlist-panel picks no longer count.
• URL storage: item URLs are stored as normalised strings.
• plugin-embed: a new finished output, emitted for every finished message. The player replays a lone play-through plugin on each one. Other users of the component don't bind it.
• Held lone items: a held webpage or plugin reports one pass, so a single-pass takeover can end.
• Other: mutedInput changes are applied, webpage iframes get sandbox="allow-scripts allow-same-origin allow-forms", hot validity checks use isMediaValid, and dead members are removed.

Testing

• Unit tests for each fix. Each fails without its fix, including a test through the real plugin-embed.
• nx test signage (432), nx test components and nx build signage pass.
• Local PlaceOS stack: all checks pass. These covered no restart on playlist edits, one preload request, no second plugin play, a preloaded plugin's fatal error, lone plugin replay over 12 rounds, single-pass with a lone webpage or plugin, a timed takeover holding until its end, blob URL count across takeovers, the sandbox, and mute.

Notes

• Chrome warns that allow-scripts + allow-same-origin can escape the sandbox. That is expected for this setting; cross-origin pages stay blocked.

Independent of the other signage PRs from this review. Based on develop.

---

Changes made by Claude Opus 5.5 (1M context) in Claude Code, running in T3 Code.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
frontend-templates	Ignored		Oct 2, 2026 3:14am UTC

[greptile-apps]

Confidence Score: 5/5

[Medium risk] Fixes media playback timing and plugin lifecycle handling.

The PR appears safe to merge; both earlier findings are addressed, and no new actionable issue was found.

What we checked:

• Old media source returns late: No. Each request has a token, and the player releases a result when that token is no longer current.
• Failed preload reused later: No. The player clears the failed output, skips another preload, and clears that skip when it starts a fresh display attempt.

Summary

The signage player keeps playback steady through playlist edits and handles plugin finishes, media URLs, and playback counts more consistently. It also limits webpage frames, applies mute to both video outputs, and updates the playback controls and media-validity checks.

• Unchanged items keep playing when a playlist changes.
• Plugin preloads and repeated finishes no longer control the wrong playback step.
• URL cleanup and playback counts follow real playback activity.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart TD
  A[Playlist changes] --> B{Item unchanged?}
  B -- Yes --> C[Keep its URL and output]
  B -- No --> D[Cancel its URL request]
  D --> E[Start a fresh request]
  F[Old request returns] --> G{Token still current?}
  G -- No --> H[Release result]
  G -- Yes --> I[Save URL]

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