feat: support documentTitle for PDF printing via document.title guard#724
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danielrose7 wants to merge 2 commits into
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feat: support documentTitle for PDF printing via document.title guard#724danielrose7 wants to merge 2 commits into
danielrose7 wants to merge 2 commits into
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For PDF iframes, Chrome uses document.title (not the iframe's <title>) for "Save as PDF" filenames. Since print() on a PDF iframe is non-blocking, Chrome reads document.title asynchronously after return. This adds a MutationObserver-based guard that temporarily holds document.title to the desired value, preventing framework re-renders (React <Head>, Vue router, etc.) from resetting it during that window. Adds documentTitleHoldMs param (default 3000ms) to let users tune the hold duration. Closes crabbly#487 Closes crabbly#66 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This was referenced Apr 23, 2026
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Two buttons added: - "Print PDF with documentTitle" — basic test, verify Chrome's print dialog shows "My Custom Report" as the filename - "Print PDF with documentTitle (simulated framework reset)" — uses a setInterval to aggressively reset document.title, proving the MutationObserver guard holds the title stable Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
document.title(not the iframe's<title>) for "Save as PDF" filenames. Sinceprint()is deferred viasetTimeout, there's a window between setting the title and Chrome actually reading it — during which a framework (React<Head>, Vue router, etc.) can reset it.MutationObserver-based guard that holdsdocument.titleto the desired value across that window, catching and reverting any mutations. Falls back gracefully whenMutationObserveris unavailable.documentTitleHoldMsparam (default3000ms) to let users tune the hold duration.Closes #487
Closes #66
Reference
Standalone helper with writeup: https://gist.github.com/danielrose7/adb604b9334118d98de6e856efd043df
Test plan
Manual test cases are included in
test/manual/index.html— runnpm start(or serve the project root) and click:document.titleevery 50ms to prove theMutationObserverguard holdsAdditional checks:
html,image,json) still work as before (no title guard, immediate cleanup)document.titleis restored after the hold perioddocumentTitleHoldMs: 500to verify custom hold durations work🤖 Generated with Claude Code