Warning: Array to string conversion in etracker_set_default_variables()

Just ran into this issue on a customer project, when trying to access a taxonomy term.

This is the line that causes the error:

$variables['et_areas'][] = implode('/', $titles);

Stacktrace:

Warning: Array to string conversion in _etracker_set_default_variables() (line 339 of modules/contrib/etracker/etracker.module).
_etracker_set_default_variables(Object) (Line: 366)
_etracker_add_variable(Object) (Line: 208)
etracker_page_attachments_alter(Array, NULL, NULL) (Line: 562)
Drupal\Core\Extension\ModuleHandler->alter('page_attachments', Array) (Line: 323)
Drupal\Core\Render\MainContent\HtmlRenderer->invokePageAttachmentHooks(Array) (Line: 289)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 580)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 290)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 132)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 142)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 174)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 2) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 2, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 2, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 2, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 2, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 2, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 2, 1) (Line: 270)
Drupal\shield\ShieldMiddleware->bypass(Object, 2, 1) (Line: 143)
Drupal\shield\ShieldMiddleware->handle(Object, 2, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 2, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 2, 1) (Line: 49)
Drupal\remove_http_headers\StackMiddleware\RemoveHttpHeadersMiddleware->handle(Object, 2, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 2) (Line: 166)
Drupal\Core\EventSubscriber\DefaultExceptionHtmlSubscriber->makeSubrequest(Object, '/system/403', 403) (Line: 112)
Drupal\Core\EventSubscriber\DefaultExceptionHtmlSubscriber->on403(Object) (Line: 109)
Drupal\Core\EventSubscriber\HttpExceptionSubscriberBase->onException(Object, 'kernel.exception', Object)
call_user_func(Array, Object, 'kernel.exception', Object) (Line: 142)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.exception') (Line: 229)
Symfony\Component\HttpKernel\HttpKernel->handleThrowable(Object, Object, 1) (Line: 92)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191)
Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128)
Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 270)
Drupal\shield\ShieldMiddleware->bypass(Object, 1, 1) (Line: 169)
Drupal\shield\ShieldMiddleware->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 49)
Drupal\remove_http_headers\StackMiddleware\RemoveHttpHeadersMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 718)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

$titles has the following content:

array(1) {
  [0]=>
  array(2) {
    ["#markup"]=>
    string(9) "Rohstoffe"
    ["#allowed_tags"]=>
    array(12) {
      [0]=>
      string(1) "a"
      [1]=>
      string(2) "em"
      [2]=>
      string(6) "strong"
      [3]=>
      string(4) "cite"
      [4]=>
      string(10) "blockquote"
      [5]=>
      string(4) "code"
      [6]=>
      string(2) "ul"
      [7]=>
      string(2) "ol"
      [8]=>
      string(2) "li"
      [9]=>
      string(2) "dl"
      [10]=>
      string(2) "dt"
      [11]=>
      string(2) "dd"
    }
  }
}

Fixes the issue. I think rendering the render array first, would be too heavy for this functionality.

LGTM! Although is there ever a case where $titles is an array, but NOT a multidimensional array? From the output you provided, it seems very unlikely, that the implode will ever execute.

@Grevil: Yes, the typical expected case here is, that it's NOT multidimensional and just contains strings of the text. You can also see this in the existing implementation.

The render array is the more untypical one, otherwise the error would appear on any page.

Alright! Thanks for the explanation! 🙂

RTBC!

Thanks @Grevil, merged!

Automatically closed - issue fixed for 2 weeks with no activity.