This was observed in changes for #2008980: Replace theme() with drupal_render() in comment module. One of the suggestions was to use parent::render() from \Drupal\comment\Plugin\views\row\Rss, which is inherited from RowPluginBase.
This is the definition of RowPluginBase::render():
function render($row) {
return array(
'#theme' => $this->themeFunctions(),
'#view' => $this->view,
'#options' => $this->options,
'#row' => $row,
'#field_alias' => isset($this->field_alias) ? $this->field_alias : '',
);
}This gives an impression that render() can return render arrays. This was the rationale behind the suggestion. However, this breaks the system.
The analysis is explained in #2008980-20: Replace theme() with drupal_render() in comment module. The patch which introduced changes to RowPluginBase::render() is at #1811828-77: Use #attached to find the css/js of a view. This is the code in RowPluginBase::render() before the patch.
function render($row) {
return theme($this->theme_functions(),
array(
'view' => $this->view,
'options' => $this->options,
'row' => $row,
'field_alias' => isset($this->field_alias) ? $this->field_alias : '',
));
}I currently see two ways to solve this.
- Fix the change introduced in #1811828-77: Use #attached to find the css/js of a view but use
drupal_renderinstead of the originaltheme()call. - Fix the following foreach loop in
\Drupal\views\Plugin\views\style\Rssto support arrays, not just strings.foreach ($this->view->result as $row_index => $row) {
$this->view->row_index = $row_index;
$rows .= $this->view->rowPlugin->render($row);
}
I am inclined towards the second approach as we are moving towards render arrays for passing data around. However, I am not entirely sure what Render API element would be the best fit here. I will post a patch as soon as I figure that out. Meanwhile, please suggest on other methods or solutions.