v146 · Web APIs · Before/After Comparison

Before/After Comparison

Side-by-side view of the old behaviour — consumer re-fires on reload — versus the Chrome 146 fix where reload is treated as a clean page load with no queued LaunchParams.

consumer firing: old vs new

Before Chrome 146 (buggy)

FIRES Initial launch from OS file association
FIRES Page reload after file-handling launch
FIRES Multiple reloads — each one re-queues original params
FIRES Hard reload (Ctrl+Shift+R) after launch

Problem: stale file handles and params from the original launch re-delivered on every reload — file-handling code runs unexpectedly, file handles may already be closed.

Chrome 146+ (fixed)

FIRES Initial launch from OS file association
SILENT Page reload after file-handling launch
SILENT Subsequent reloads — no params to re-queue
SILENT Hard reload after launch

Fix: reload = fresh page load. LaunchParams are consumed once, never stored for re-delivery. Consumer only fires on genuine launches.

lifecycle: file launch then reload

1 User opens report.csv from the OS — browser launches the PWA with a file association
2 launchQueue.setConsumer() fires — LaunchParams.files contains the file handle; PWA reads and opens the file
3 Pre-146 only: user reloads the page → Chrome re-queues the original LaunchParams → consumer fires again with the same (now possibly expired) file handle
3 Chrome 146+: user reloads the page → browser treats it as a new page load → consumer does not fire → file-handling code stays idle

code implications

// ✓ Standard pattern — works correctly in Chrome 146+
if ('launchQueue' in window) {
  launchQueue.setConsumer(async launchParams => {
    for (const handle of launchParams.files) {
      const file = await handle.getFile();
      await openInEditor(file);
    }
  });
}

// If you relied on reload-retrigger to survive page refreshes (rare),
// use sessionStorage to persist launch state across reloads instead:

launchQueue.setConsumer(async launchParams => {
  // Store metadata (not handles — those can't be serialised)
  const names = launchParams.files.map(h => h.name);
  sessionStorage.setItem('pendingFiles', JSON.stringify(names));

  // Process files from the actual live handles immediately
  for (const handle of launchParams.files) {
    const file = await handle.getFile();
    await openInEditor(file);
  }
});

// On next page load (e.g. after reload) you can show UI
// based on the stored names — but re-open via your own
// logic, not by re-reading launchParams (won't arrive).

scenario focus

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