TypeError: implode(): Argument #1 ($pieces) must be of type array, string given in implode() (line 29 of /app/web/core/lib/Drupal/Core/Form/FormElementHelper.php)

The patch for the <strong>FormElementHelper</strong> has been provided.

Thanks for providing steps. Have not a full change to verify but this seems like a larger issue could be at work.

But as a bug will need a test case.

the numbering on the patch is wrong. but it fixed the problem for me.

Hi The patch #2 fixes the issue on media library for alt text. but as mentioned in #5 the patch name is not correct. updated the patch.

Thank!

Ran into an issue today that triggered this for us in Drupal 10. Patch from #6 fixed the issue.

Created a MR from patch #6
MR: https://git.drupalcode.org/project/drupal/-/merge_requests/8297
Branch: 3353388-type-error-implode

I have reached this issue after having the same error using Inline Entity Form. The error appeared when developing a custom validation via "#element_validate", specifically when I called the setError method. I mention it in case it would be interesting that the test also covered this case. The path #6 fixes the issue.

I ran into this issue on an Open Social site, where a flexible group creation form had a taxonomy term entity reference field. Without the patch, there was no $form[$key]['#parent'] which led to a WSOD. The patch here showed the error message in the wrong place instead of the entire form white screening.

Confirming that patch #6 fixes the issue, but do not have time at the moment to contribute a test case to support the fix.

As per Comment #4, I have created the Test case for the patch. Verified the patch changes, Seems require manual test for change. The code changed for FormElementHelper.php, the class used in all form.

The Needs Review Queue Bot → tested this issue. It no longer applies to Drupal core. Therefore, this issue status is now "Needs work".

This does not mean that the patch necessarily needs to be re-rolled or the MR rebased. Read the Issue Summary, the issue tags and the latest discussion here to determine what needs to be done.

Consult the Drupal Contributor Guide → to find step-by-step guides for working with issues.

arunkumark → changed the visibility of the branch 3353388-type-error-implode to hidden.

arunkumark → changed the visibility of the branch 3353388-typeerror-implode-argument to hidden.

Mr shouldn’t be against 11.0

The previous MR was pointing to the correct branch why open a new one?

arunkumark → changed the visibility of the branch 3353388-type-error-implode to active.

arunkumark → changed the visibility of the branch 3353388-type-error-implode-fix to hidden.

arunkumark → changed the visibility of the branch 3353388-type-error-implode-d11 to hidden.

I faced the issue of creating MR against the 11.x branch. Now it is working to update the MR

The MR is almost 500 commits back

Done the backmerge to 11.x

Removing tests tag as https://git.drupalcode.org/issue/drupal-3353388/-/jobs/3078752 shows coverage.

believe rest of the feedback has been addressed.

How are we getting form elements with no parents. I think it points to unprocessed part of the form being added at the wrong point (after ) and to a larger issue.

Note I've followed the instructions in the error is no longer reproducible for a media field so I think we fixed this in a different, probably better, way.

I've tried to re-create the problem on 11.x, 10.1.0 and 10.0.0 following the steps in the issue summary and it did not work. Also this is very similar to 🐛 Notice: Undefined index: #parents in a Form/FormElementHelper.php Needs work