Get parent of term - timber

Question

I might have missed it in the Timber Docs but is there a possibility to get the parent terms of a given taxonomy?

Answer 1

two methods depending on Twig vs. PHP and what exactly you're looking to do.
Consider a post which as been assigned a category of "Politics" (which is a child category of "News")
Example 1: Get a parent term in a Twig file
<p>Find more posts in {{ post.category.name }} and {{ post.category.parent.name }}</p>
<!--- outputs as ... --->
<p>Find more posts in Politics and News</p>
Example 2: Get the top-level terms from a taxonomy
$context['parent_categories'] = Timber::get_terms(array('taxonomy' => 'category', 'parent' => 0));
Use in Twig like...
Top-level categories for my site are...
{% for term in parent_categories %}
<li>{{ term.name }}</li>
{% endfor %}
<!-- Outputs as... -->
<li>News</li>
<li>Sports</li>
<li>Opinion</li>

Answer 2

Let's say you are trying to use the parent of a category in a twig view. That was the case I tried to solve when stumbling upon this post.
In category.php you can get the parent category by getting the parent category ID of the currently viewed category:
$category = new TimberTerm();
$context['category'] = $category;
if ($category->parent) {
$context['parent_category'] = new TimberTerm($category->parent);
}
$category->parent corresponds to the ID of the parent category. It is null if the category doesn't have a parent. You can then use the resulting category in your template.
<a class="category_{{parent_category.slug|lower}}" href="{{parent_category.link}}">
{{parent_category.title}}
</a>