Count of nodes filter in views for a taxonomy with depth

Question

sorry for my English.

In views, Drupal 8/9, is it possible to have the count of nodes for a taxonomy-term with depth? I would like to have it for the filters in views.

I can't find any modules to get this information. Maybe I don't know how to look or a complex module gives this possibility but I couldn't find it.

Aggregation doesn't really help me. Performance is not a problem.

Answer 1

There are several ways to do it, based on how you are going to manage your content.
But for your problem I guess the solution can be this:

1. In Fileds: add Taxonomy term: Name
2. In Relationships, add a Taxonomy term: Content with term
3. Add a contextual filter for Taxonomy term: Name
    3a. Choose 'Display a summary'
    3b. Choose 'Display Record count with link'.

Here is several resources that can help:
Views and node count for taxonomy terms
How to display number of nodes with current term?
Showing how many nodes are associated with a term
Display node count per node reference field

Answer 2

We have to write a module, something like this

/modules/childs_count/childs_count.views.inc

function childs_count_views_data()
{

  $data['taxonomy_term_field_data']['childs_count'] = array(
    'title' => t('Childs count'),
    'help' => t('Get the number of childs in taxo.'),
    'field' => array(
      'id' => 'childs_count'
    ),
    'filter' => [
      'id' => 'childs_count_filter',
    ],
  );

  return $data;

}

/modules/childs_count/childs_count.module

//to do add limit and type..
function childs_count_query($depth = 5)
{
  if ($depth < 1) {
    $depth = 1;
  }
  $sql = "(
  SELECT COUNT(nid) FROM node_field_data WHERE node_field_data.nid IN (
    SELECT tn.nid AS nid FROM taxonomy_index tn
            LEFT JOIN taxonomy_term__parent th ON th.entity_id = tn.tid
            LEFT JOIN taxonomy_term__parent th1 ON th.parent_target_id = th1.entity_id";
  foreach (range(1, $depth - 1) as $level) {
    $sql .= "\n\tLEFT JOIN taxonomy_term__parent th" . ($level + 1) . " ON th" . $level . ".parent_target_id = th" . ($level + 1) . ".entity_id\n";
  }

  $sql .= "WHERE (tn.tid = taxonomy_term_field_data.tid)";
  foreach (range(1, $depth) as $level) {
    $sql .= "\nOR (th$level.entity_id = taxonomy_term_field_data.tid)";
  }
  $sql .= ")\n)\n";

  return $sql;
}

/modules/childs_count/src/Plugin/views/field/fieldChildsCount.php

namespace Drupal\childs_count\Plugin\views\field;

use Drupal\views\Plugin\views\field\NumericField;


/**
 * Field handler for search snippet.
 *
 * @ingroup views_field_handlers
 *
 * @ViewsField("childs_count")
 */
class ChildsCount extends NumericField
{

  public function query()
  {

    $this->field_alias="comptage";
    $this->query->addField(NULL, childs_count_query(), $this->field_alias);

  }

}

/modules/childs_count/src/Plugin/views/filter/ChildsCountFilter.php

namespace Drupal\childs_count\Plugin\views\filter;

use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Plugin\views\filter\NumericFilter;

/**
 * Defines a filter for filtering on numeric values.
 *
 * @ingroup views_filter_handlers
 *
 * @ViewsFilter("childs_count_filter")
 */
class ChildsCountFilter extends NumericFilter
{


  public function query()
  {
    $this->ensureMyTable();
    $where = $this->operator . ' ' . $this->value['value'];
    $this->query->addWhereExpression($this->options['group'], childs_count_query() . " $where");
  }

  /**
   * {@inheritdoc}
   */
  public function operators()
  {
    $operators = parent::operators();
    unset($operators['regular_expression']);
    unset($operators['between']);
    unset($operators['not between']);
    return $operators;
  }

  protected function valueForm(&$form, FormStateInterface $form_state)
  {
    parent::valueForm($form, $form_state);
    unset($form['value']['min']);
    unset($form['value']['max']);
  }
}

I will do it. it's not good for server performance, but it suits me. Thanks for your help.