TypeError: preg_match_all(): Argument #2 ($subject) must be of type string, array given in preg_match_all()

How did you trigger this error? Were you viewing a node page? Were you editing configuration somewhere?

Get the same error when saving a content like an article (Metatag 1.19, Drupal 9.3, Php 8.0, Ubuntu 20..LTS.

The website encountered an unexpected error. Please try again later.
TypeError: preg_match_all(): Argument #2 ($subject) must be of type string, array given in preg_match_all() (line 240 of core/lib/Drupal/Core/Utility/Token.php).

Thank you for the patch. It works for me - tested with standard processes with my Drupal test installation so far.

I receive the same warning on drupal 9.3.5 and metatag 1.19.0. The metatag "mask_icon" seems to trigger it in my case.

Confirmed that I'm seeing this issue crop up specifically after updating to Drupal 9.3.5 and Metatag 1.19.0. Like @captain_hindsight, I also see this issue with the "mask_icon" metatag.

• Visit /admin/config/search/metatag
• Configure the Global metatags
• Specify a "Mask icon (SVG)" value
• Save
• View any page that uses the global metatags, with full error reporting enabled, you now get the preg_match_all() error at the top of the page.

In the metatag.metatag_defaults.global.yml, the mask icon seems to not use the same format as all other tags. Instead of a string value, it's a multivalue array:

  mask_icon:
    href: /themes/custom/curio/assets/images/metadata/safari-pinned-tab.svg
    color: ''

And then when the token is getting replaced, the array of both href and color is getting passed in, rather than just the href string.

That said, I don't think the current patch is the right fix. We should be fixing the data that gets passed in, not just skipping the metatag output.

I found that \Drupal\metatag\MetatagManager::generateRawElements already use some logic for dealing with array values. Why don't we use similar in \Drupal\metatag\MetatagManager::generateTokenValues

The patch with draft changes. Need to look closer. Probably this logic should also be obtained to separate method to not repeat it twice.

(It seems the last patch passed all the tests, contrary to what the previous comment says.)

Comment #2 asked:

How did you trigger this error? Were you viewing a node page? Were you editing configuration somewhere?

The IS should be updated with an answer to those questions.

Adding patch with tests. Set Needs Review to tests be running. But it needs further work to avoid code duplication.

Oh, latest patch metatag-typeerror-preg_match_all-3258427-14.patch do not contains tests. Here the proper patch with test and fix.

After follow the Steps to reproduce I get the error below:

My environment:
- Drupal 9.4.0-dev
- Metatag 8.x-1.x
- PHP 8.1

After apply patch #16 the issue is resolved

This is the patch with same logic as #16, but the repeatitive code was extracted to the protected method processTagValue().
And there are a couple of typos fixes in the comments in MetatagManager.php

Cannot apply patch #19

The tests apply the patch to test it. If the patch would not be applicable, the tests would not run.

The tests fail to apply, please help to check again.

Rerolled patch

Weird thing with tests. First run fails, but if rerun - passes.

I have the same issue with Metatag 1.19.0. When adding a new metatag setting for a node type of your choice, an empty mask_icon key gets added. Opening a node of that type leads to the reported error message.
Patch #24 can't be applied to 1.19.0.

#24 is for current dev branch. I think #19 should be suitable for 1.19

#19 didn't apply against 1.19.0 either.
Here's a slightly adapted version of #19 which does apply, but unfortunately doesn't fix the issue – the empty mask icon entry still gets added and crashes the node's detail page.
Patch added just for the record, thus hiding it.

Great work, thank you all!

If there are additional scenarios that trigger similar problems, please open a new issue.