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fix: prevent duplicate iframes on CldUploadWidget unmount/remount - #658

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PaulBoye-py merged 1 commit into
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fix/widget-unmount-duplicate-iframes
Sep 15, 2026
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PaulBoye-py merged 1 commit into
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fix/widget-unmount-duplicate-iframes

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Description

When CldUploadWidget unmounts and remounts, next/script's onLoad callback fires again (the script is already cached in the browser, but the callback re-registers on remount). The existing triggerOnIdle callback had no guard against the component unmounting before the idle callback fired, thus allowing a zombie widget instance to be created with an orphaned iframe in the DOM.

Root cause: triggerOnIdle defers widget creation asynchronously via requestIdleCallback. If the component unmounts during that window, the cleanup runs (widget.current = undefined), but the pending idle callback still fires, passes the !widget.current check, and creates a new widget on an unmounted component.

Fix: Add an isMounted ref that gates both the handleOnLoad entry point and the async idle callback. The single cleanup useEffect sets isMounted.current = false before calling widget.current?.destroy(), ensuring no in-flight callbacks can recreate the widget after cleanup.

A manual test page has been added at tests/nextjs-app/app/test-widget/page.tsx to verify the fix via unmount/remount cycling in the browser.

Issue Ticket Number

Fixes #587. Supersedes #588.

Type of change

  • Bug fix (non-breaking change which fixes an issue)

Checklist

  • I have followed the contributing guidelines of this project as mentioned in CONTRIBUTING.md
  • I have created an issue ticket for this PR
  • I have checked to ensure there aren't other open Pull Requests for the same update/change
  • I have performed a self-review of my own code
  • I have run tests locally to ensure they all pass
  • I have commented my code, particularly in hard-to-understand areas
  • I have made corresponding changes needed to the documentation

When CldUploadWidget unmounts and remounts, next/script's onLoad fires
again. The triggerOnIdle callback had no guard against the component
unmounting before the idle callback fired, allowing a zombie widget to
be created with an orphaned iframe.

Add an isMounted ref that gates both handleOnLoad and the idle callback.
Set isMounted=true on mount; false + destroy on cleanup, in that order.

Closes #587. Supersedes #588.
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@PaulBoye-py
PaulBoye-py merged commit f3b1fee into main Sep 15, 2026
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@PaulBoye-py

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supersedes #588

@PaulBoye-py
PaulBoye-py deleted the fix/widget-unmount-duplicate-iframes branch September 15, 2026 21:12
eportis-cloudinary added a commit that referenced this pull request Sep 25, 2026
Brings 146 commits from main onto the v7 branch, including Next.js 16
compatibility (#657), the Node 20/22 CI matrix (#656), the Trusted
Publishers release plumbing, and three recent fixes: duplicate iframes on
CldUploadWidget unmount (#658), open() called before the widget script
loads (#659), and the docs Table component (#661).

Conflicts resolved as follows:

- CldVideoPlayer.tsx: union. Kept beta's 'use client' and named-only
  react import, added main's useState, which the merged body needs for
  isScriptLoaded/playerInitialized.
- next-cloudinary/package.json: kept beta's preconstruct build config,
  exports map, files and 7.0.0-beta.11 version; adopted the repository
  field main added in 554e2a0.
- package.json: kept @preconstruct/cli (beta's build needs it); dropped
  @colbyfayock/semantic-release-pnpm, which the merged .releaserc no
  longer references; took main's semantic-release 25 and
  @semantic-release/npm 13.
- pnpm-workspace.yaml: beta's list, which adds the test app - required
  because beta's test:app builds it via pnpm rather than npm install.
- tests/nextjs-app/package.json: main's Next 16 / React 19 versions plus
  beta's next-cloudinary workspace link.
- CHANGELOG.md: kept both release histories.
- pnpm-lock.yaml: regenerated against the merged manifests.

Also fixes CldUploadWidget.tsx, which git auto-merged without conflicting
but produced broken output: beta had dropped the default React import
while main's useUploadWidgetId helper calls React.useId and React.useRef.
The combination built fine and failed at prerender with "ReferenceError:
React is not defined". Restored the default import. Caught by test:app,
not by the unit tests.

Note: .releaserc auto-merged to main's @semantic-release/npm, which drops
beta's publishBranch "main|beta" setting. Branch gating now comes from
the top-level branches config alone.

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Successfully merging this pull request may close these issues.

[Bug] Duplicate iframes created when <CldUploadWidget /> re-renders

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