Templates aren't called in custom module?

Question

I am trying to add templates for the paragraph in a custom module, but it uses only the paragraph.html.twig template file.

paragraph--example-ch-hero-panel.html.twig is one of the suggested template files, which is the one I am using.

By default, The template should be taken from the paragraph, but it doesn't work in my case. I didn't implement hook_theme() in a module for this because I am not passing any value to the templates.

I tried the following code, but I got an error.

function example_ch_hero_panel_theme() {
  return [
    'paragraph__example_ch_hero_panel' => [
      'render element' => 'element',
      'template' => 'paragraph--example-ch-hero-panel',
      'base hook' => 'paragraph',
    ],
  ];
}

function example_ch_hero_panel_theme_registry_alter(&$theme_registry) {
  $theme_registry['page']['path'] = drupal_get_path('module', 'example_ch_hero_panel') . '/templates';
}

It throws the following exception.

Twig\Error\LoaderError: Template "modules/custom/example_ch_hero_panel/templates/page.html.twig" is not defined. in Twig\Loader\ChainLoader->getCacheKey()

Can anyone tell me how to fix this issue?

Answer 1

Your problem is coming from this code:

$theme_registry['page']['path'] = drupal_get_path('module', 'example_ch_hero_panel') . '/templates';

The first array key, page, means you are working the page template. You've told the system to look for page.html.twig in your module's /templates directory. It's not finding it, so you get that error.

Remove that hook altogether, it's not the right way to do what you are trying to do.

Answer 2

The following code is taken from a module that creates an accordion from a paragraph. (The module name has been changed.)

The paragraph--accordion.html.twig template file exists in mymodule/templates/paragraph.

function mymodule_theme($existing, $type, $theme, $path) {
  $themes['paragraph__accordion'] = array(
    'template' => 'paragraph--accordion',
    'base hook' => 'paragraph',
    'path' => \Drupal::service('extension.list.module')->getPath('mymodule') . '/templates/paragraph'
  );

  return $themes;
}