Prevent editor creation on detached element

[sculpt0r]

What is the purpose of this pull request?

New feature

Does your PR contain necessary tests?

All patches that change the editor code must include tests. You can always read more
on PR testing,
how to set the testing environment and
how to create tests
in the official CKEditor documentation.

This PR contains

• Unit tests
• Manual tests

Did you follow the CKEditor 4 code style guide?

Your code should follow the guidelines from the CKEditor 4 code style guide which helps keep the entire codebase consistent.

• PR is consistent with the code style guide

What is the proposed changelog entry for this pull request?

* [#4461](https://github.com/ckeditor/ckeditor4/issues/4461): Delay editor creation if target element is detached.

What changes did you make?

Give an overview…

• If config.delayDetached is true and target element isDetached: immediately return null and start checking in 1000ms periods.
• If target element is attached -> create an editor instance and stop checking.
• Editor will be available e.g. inside onInstanceReady via this

CKEDITOR.replace( textArea, {
	delayDetached: true,
	on: {
		instanceReady: function(evt) {
			this.setData("Editor created");
		}
	}
} )

Which issues does your PR resolve?

Closes #4461 .

[f1ames]

CI is red for this PR could you check what's going on?

Could you also provide unit tests which covers this case?

[sculpt0r]

CI is red for this PR could you check what's going on?

Could you also provide unit tests which covers this case?

Initially, it was red because I didn't check if the config exists before use it. I fixed this.

Now it's only red for `BROWSER=Firefox MOZ_HEADLESS=1`. One of them shows fail with pdf export and second tests/plugins/pastefromlibreoffice/generated/imagesextraction

I restart one of them to check if there is any randomness.

[f1ames]

fail with pdf export

This is a known issue we have already reported so it's not caused by this PR.

and tests/plugins/pastefromlibreoffice/generated/imagesextraction

And this is not so if it still fails after restart it means this PR may be the cause here.

[sculpt0r]

fail with pdf export

This is a known issue we have already reported so it's not caused by this PR.

and tests/plugins/pastefromlibreoffice/generated/imagesextraction

And this is not so if it still fails after restart it means this PR may be the cause here.

The second run: shows only fail with pdf on single BROWSER=Firefox MOZ_HEADLESS=1.

I will make all correct and I'll back to verify CI

[sculpt0r]

Also, I add new CKEditor error code, and made a ckeditor4-docs PR: ckeditor/ckeditor4-docs#344

[sculpt0r]

CI is green (except pdf exporter). Ready for review.

[github-actions]

It's been a while since we last heard from you. We are marking this pull request as stale due to inactivity. Please provide the requested feedback or the pull request will be closed after next 7 days.

[github-actions]

There was no activity regarding this pull request in the last 14 days. We're closing it for now. Still, feel free to provide us with requested feedback so that we can reopen it.

[sculpt0r]

Waiting for next planing, after release

[sculpt0r]

Rebase onto newest major.

[github-actions]

It's been a while since we last heard from you. We are marking this pull request as stale due to inactivity. Please provide the requested feedback or the pull request will be closed after next 7 days.

[github-actions]

There was no activity regarding this pull request in the last 14 days. We're closing it for now. Still, feel free to provide us with requested feedback so that we can reopen it.

[f1ames]

Rebased onto latest major.

[f1ames]

LGTM 🎉 Good job @sculpt0r and @Dumluregn 👏 👏 👏

---

• added two manual tests: detachedcustomcallbackmobile and detachedcustominterval. Both are ignored in the non-mobile environment - since the test cases are the same as detachedcustomcallback and detachedcustominterval. However, I added message field in those tests. Because on mobile (at least mine) some operations are so slow, that in the first place you can think that nothing happened. So this field informs about the current stage.
• For detachedcustomcallback and detachedcustominterval I added mobile ignore.

👍

Please take a look at #4463 (comment). Should I create follow up?

Yes, please 👍

---

Rechecked tests on IE9 and IE10 - everything's green ✔️

[f1ames]

Just waiting for the CI to finish after rebase and I'll be merging this PR 👍

[sculpt0r]

Yes, please +1

Created: #4641