I am trying to develop a Drupal 8 module in which I have to override the html.html.twig template. The idea is that I do not want any of the default html.html.twig template returned instead I only want the custom template returned. I have been spending hours Google hunting and trying to make sense of the many examples and I have gotten myself totally confused.
What is happening is the content of my custom template are being displayed in the default html template so I am seeing the custom content inside the default html template rather than overriding the default content.
For the sake of getting this template override working I have simplified the module as much as possible and simply want to return the contents of a variable into a placeholder in the twig template. Once this override is working I can go back and add the code that will create the correct content to be output into a number of variables in the template.
What I do not understand is exactly how to I override the html.html.twig template.
My module is called unsw_blocks and in the unsw_blocks.module I have the following
function unsw_blocks_theme() {
$theme = [
'unsw_blocks' => [
'variables' => ['test_var' => NULL],
],
];
return $theme;
}
In the Unsw_blocksController.php have the following
class Unsw_blocksController extends ControllerBase {
public function unsw_blocks($name) {
return [
'#theme' => 'unsw_blocks',
'#test_var' => $this->t('The variable called test_var simply passes this text itself to the theme template'),
];
}
}
In the custom modules templates directory I have unsw-blocks.html.twig which simply contains
<h1>Testing Template</h1>
<p>test_var: {{ test_var }}</p>
