`Page` has limited built-in metatag features, disable advanced form fields there as initial stop-gap

Added screenshot.

Added more info on which bits are metatag code in XB.

@catch: I think its also fine to do something along these lines in XB. As said this is a stop-gap.

@damienmckenna: XB adds the metatags field as a base field, and it is set as internal but also configurable (see code snippet below) :D I don't think there is a way to actually configure this, it does not show up on admin/reports/fields and also XB does not have a way to edit the fields on XB entities (by design I think).

Does metatag need the field to be present to pull from the description and image base fields for metadata? The only thing that XB pulls out of this for its own SEO settings is $form['metatags']['widget'][0]['basic']['title'].

I think "out of the advanced section" in code terms if sidebar FALSE? When I tried that it merely made the metatag fields show up above the SEO settings section. Same problem with robots field then though :)

  #[Hook('entity_base_field_info')]
  public function entityBaseFieldInfo(EntityTypeInterface $entity_type): array {
    $fields = [];
    if ($entity_type->id() === Page::ENTITY_TYPE_ID) {
      if ($this->moduleHandler->moduleExists('metatag')) {
        $fields['metatags'] = BaseFieldDefinition::create('metatag')
          ->setLabel(new TranslatableMarkup('Metatags'))
          ->setDescription(new TranslatableMarkup('The meta tags for the entity.'))
          ->setTranslatable(\TRUE)
          ->setDisplayOptions('form', [
            'type' => 'metatag_firehose',
            'settings' => ['sidebar' => \TRUE, 'use_details' => \TRUE],
          ])
          ->setDisplayConfigurable('form', \TRUE)
          ->setDefaultValue(Json::encode([
            'title' => '[xb_page:title] | [site:name]',
            'description' => '[xb_page:description]',
            'canonical_url' => '[xb_page:url]',
            // @see https://stackoverflow.com/a/19274942
            'image_src' => '[xb_page:image:entity:field_media_image:entity:url]',
          ]))
          ->setInternal(\TRUE)
          ->setProvider('metatag');
      }
    }
    return $fields;
  }

Does XB really need the metatags field on the entity for metatag to work? The easiest would be to not even have the field on :)

This is with sidebar FALSE :)

Let me repeat the key question: Does metatag [module] need the [full metatag] field to be present to pull from the description and image base fields for metadata?

@mglaman: with that alter the basic elements go away as expected, the closeable metatags section becomes a non-closeable Advanced but the robots checkboxes are still there and therefore lead to the error described. Is that the full extent of the alter you use? All these fields are still present with that alter hook from #13 which I doubt you all expose to users @mglaman :) I'm using metatag 2.1.1.

Adding related issue in #3526130: \Drupal\experience_builder\ClientDataToEntityConverter::setEntityFields doesn't work with booleans outside of boolean field that may cause the checkbox to not work. Even if that would work I think "metatag" working fine is not quite leaving every single field as-is in the sidebar, so lacking further product direction I think leaving all but the XB base field provided (image / description) SEO stuff out for now would be much better. Otherwise (even if the checkboxes then work fine) enabling metatag throws this massive amount of form elements, most of which are quite confusing and super advanced.

That said, until the checkboxes get fixed we do need a workaround that keeps metatag working IMHO.

@damienmckenna: are these mappings possible to reproduce in a global config somehow? I think the reason for the field is to use these mappings for xb metadata (unless explicit settings otherwise).

          ->setDefaultValue(Json::encode([
            'title' => '[xb_page:title] | [site:name]',
            'description' => '[xb_page:description]',
            'canonical_url' => '[xb_page:url]',
            // @see https://stackoverflow.com/a/19274942
            'image_src' => '[xb_page:image:entity:field_media_image:entity:url]',
          ]))

Had a zoom meeting with Lauri where I showed him the current state. XB has an opinion on what basic SEO fields should be shown and implements all of them as base fields (except the SEO title). So the metatag field is mostly used to wire in the token replacements as shown above in #17. I understand this could be in global config for this entity type. Lauri told me that keeping the field would still be better as it would give the option to create a custom, simpler widget for more complicated SEO settings in the future. I think the field could still be added then, but my aim is to solve metatags not working with XB, not to argue about architecture :)

So attaching a few lines of added code that alters out the metatag section of the form at the existing place where it moves the SEO title field. This works for me, although I don't have the SEO title field somehow in metatag 2.1.1 that I have, so not sure if that would be affected by the #access even though it is moved out of the group. I think for this stop-gap issue that is the remaining question.

I understand that @damienmckenna. I don't have an opinion either way, so I personally leave considering that to @lauriii and/or other code owners in this area of XB :) My main aim is to make metatag and XB work peacefully together, I don't have architectural opinions about this, trying to help with whatever is needed :)

The remaining fails are around #edit-seo-settings #edit-metatags-0-basic-title of course. I still did not find where this one comes from metatag, but access false-ing the parent does make this inaccessible apparently.

Would be good to get a clear answer from the XB team whether the field should stay and further altering should be put into place (as in #13 but that does not list all the items, see #14) or the field should be removed (which does sound like would be the cleaner solution IMHO).

Re #13, basically this was missing in my MR compared to #13. I don't think this should be committed as-is but this does make metatag work with XB and not emit any scary widgets :)

      $form['metatags']['widget'][0]['advanced']['#access'] = FALSE;

Also adding the current diff file for composer patching purposes.

Moving to Canvas.

Also update title and issue summary.

Patch for Canvas for composer patching. I merely do this to maintain xb-demo, not to take sides in what is the best solution.

Neither the phpstan nor the playwright fails are related to this issue, so I think the (basic) MR is ready for review :) If we want to keep the widget in a selective form, we'll need to start from a more strict place, because the lots of advanced elements are too much that appear without this patch :)