Create a theme suggestion for taxonomy terms by view mode

Attaching a new patch that is sanitising the view mode, the same way node_theme_suggestions_node() does.

RTBC, but core committers might ask for a test for this.

FYI:

1. I'm moving this for 8.3.x and committers can decide if this could be included in 8.2.x also.
2. This could possibly face similar problems as this #2229355: Field template suggestions are colliding why it might make sense to figure out that issue first.

This is very similar to #2766379: Add User view mode template suggestions, is it worth adding these centrally somewhere? Also we should look at #9.2 here as well.

Sorry folks, but I think this should be fixed here instead: #2270883: Automatically add theme hook suggestions for all entity types

Hi,
I reorder suggestions of #6 to have view_mode before and make suggestion more generic. I hope it will help!

Fixed #13, sorry

I have tested the patch in comment #14 on drupal version 8.5.1 and the taxonomy term theme suggestions by view mode are displaying as excepted.

23 = tid
audience = vocabulary machine name
teaser = view mode

<!-- FILE NAME SUGGESTIONS:
   * taxonomy-term--23--teaser.html.twig
   * taxonomy-term--23.html.twig
   x taxonomy-term--audience--teaser.html.twig
   * taxonomy-term--audience.html.twig
   * taxonomy-term--teaser.html.twig
   * taxonomy-term.html.twig
-->

confirmed #14 works

Here's a workaround. Since the other task isn't complete, and this patch will not be going in.

/**
 * Implements hook_theme_suggestions_taxonomy_term_alter().
 */
function YOURTHEME_theme_suggestions_taxonomy_term_alter(array &$suggestions, array $variables) {
  /** @var \Drupal\taxonomy\TermInterface $term */
  $term = $variables['elements']['#taxonomy_term'];
  $sanitized_view_mode = strtr($variables['elements']['#view_mode'], '.', '_');
  // Add view mode theme suggestions.
  $suggestions[] = 'taxonomy_term__' . $sanitized_view_mode;
  $suggestions[] = 'taxonomy_term__' . $term->bundle() . '__' . $sanitized_view_mode;
  $suggestions[] = 'taxonomy_term__' . $term->id() . '__' . $sanitized_view_mode;
}

#17 works for me. Thanks. Just add to the theme file and build any suggestion that you want.

#17 Works for me. Thanks

A different approach that you could follow is to create
taxonomy-term--services.html.twig (services = vocabulary machine name) for your vocabulary and check (if view_mode == 'teaser') the machine name of your view modes

{% if view_mode == 'teaser' %}
     <div class="svglink">
         {{ content.field_svgimg }}
     </div>
{% endif %}


{% if view_mode == 'full' %}

  {%
    set classes = [ 'taxonomy-term',  'vocabulary-' ~ term.bundle|clean_class, ]
  %}

  <div{{ attributes.setAttribute('id', 'taxonomy-term-' ~ term.id).addClass(classes) }}>
    {{ title_prefix }}
    {% if not page %}
      <h2><a href="{{ url }}">{{ name }}</a></h2>
    {% endif %}
    {{ title_suffix }}
    <div class="content">
      {{ content }}
    </div>
  </div>
  
{% endif %}

Hm, wondering why not getting #14 in. It's more than three years since the issue was opened and no more general solution seems to be in sight anytime soon. So why not having it the same way that node does it for taxonomy too, maybe with a ToDo hint to remove it if a more general solutions will finally be available.

Even taxonomy_theme_suggestions_taxonomy_term() is already there and only needs to be amended slightly, so the risk with this change seems to be very small.

And regarding tests: At this moment taxonomy module does no tests on the suggestions although suggestions are already created. But if only tests are hindering, than I could maybe provide them analogous to how node does it.

Kindly asking maintainers to maybe have a look on this issue again.

Agreed with Stefan.

Contrib solution for now: Twig Template Suggester module

For those of us who are digging through issues trying to find what the latest status is, some work going on here: https://www.drupal.org/project/drupal/issues/2808481

#17 works great 👍

#17 Works for me. Thanks

#14 works great.

It is nice that this has been closed as a duplicate of https://www.drupal.org/project/drupal/issues/2270883 BUT that issue has been bogged down since 2014. Similarly in https://www.drupal.org/project/drupal/issues/2808481 also stuck in a bog.

#14 doesn't seem to apply on latest core but #17 is the way to go for now.

Re-rolled #14.