class TermViewsData

class TermViewsData extends EntityViewsData {
    
    /**
     * {@inheritdoc}
     */
    public function getViewsData() {
        $data = parent::getViewsData();
        $data['taxonomy_term_field_data']['table']['base']['help'] = $this->t('Taxonomy terms are attached to nodes.');
        $data['taxonomy_term_field_data']['table']['base']['access query tag'] = 'taxonomy_term_access';
        $data['taxonomy_term_field_data']['table']['wizard_id'] = 'taxonomy_term';
        $data['taxonomy_term_field_data']['table']['join'] = [
            // This is provided for the many_to_one argument.
'taxonomy_index' => [
                'field' => 'tid',
                'left_field' => 'tid',
            ],
        ];
        $data['taxonomy_term_field_data']['tid']['help'] = $this->t('The tid of a taxonomy term.');
        $data['taxonomy_term_field_data']['tid']['argument']['id'] = 'taxonomy';
        $data['taxonomy_term_field_data']['tid']['argument']['name field'] = 'name';
        $data['taxonomy_term_field_data']['tid']['argument']['zero is null'] = TRUE;
        $data['taxonomy_term_field_data']['tid']['filter']['id'] = 'taxonomy_index_tid';
        $data['taxonomy_term_field_data']['tid']['filter']['title'] = $this->t('Term');
        $data['taxonomy_term_field_data']['tid']['filter']['help'] = $this->t('Taxonomy term chosen from autocomplete or select widget.');
        $data['taxonomy_term_field_data']['tid']['filter']['hierarchy table'] = 'taxonomy_term__parent';
        $data['taxonomy_term_field_data']['tid']['filter']['numeric'] = TRUE;
        $data['taxonomy_term_field_data']['tid_raw'] = [
            'title' => $this->t('Term ID'),
            'help' => $this->t('The tid of a taxonomy term.'),
            'real field' => 'tid',
            'filter' => [
                'id' => 'numeric',
                'allow empty' => TRUE,
            ],
        ];
        $data['taxonomy_term_field_data']['tid_representative'] = [
            'relationship' => [
                'title' => $this->t('Representative node'),
                'label' => $this->t('Representative node'),
                'help' => $this->t('Obtains a single representative node for each term, according to a chosen sort criterion.'),
                'id' => 'groupwise_max',
                'relationship field' => 'tid',
                'outer field' => 'taxonomy_term_field_data.tid',
                'argument table' => 'taxonomy_term_field_data',
                'argument field' => 'tid',
                'base' => 'node_field_data',
                'field' => 'nid',
                'relationship' => 'node_field_data:term_node_tid',
            ],
        ];
        $data['taxonomy_term_field_data']['vid']['help'] = $this->t('Filter the results of "Taxonomy: Term" to a particular vocabulary.');
        $data['taxonomy_term_field_data']['vid']['field']['help'] = t('The vocabulary name.');
        $data['taxonomy_term_field_data']['vid']['argument']['id'] = 'vocabulary_vid';
        unset($data['taxonomy_term_field_data']['vid']['sort']);
        $data['taxonomy_term_field_data']['name']['field']['id'] = 'term_name';
        $data['taxonomy_term_field_data']['name']['argument']['many to one'] = TRUE;
        $data['taxonomy_term_field_data']['name']['argument']['empty field name'] = $this->t('Uncategorized');
        $data['taxonomy_term_field_data']['description__value']['field']['click sortable'] = FALSE;
        $data['taxonomy_term_field_data']['changed']['title'] = $this->t('Updated date');
        $data['taxonomy_term_field_data']['changed']['help'] = $this->t('The date the term was last updated.');
        $data['taxonomy_term_field_data']['changed_fulldate'] = [
            'title' => $this->t('Updated date'),
            'help' => $this->t('Date in the form of CCYYMMDD.'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_fulldate',
            ],
        ];
        $data['taxonomy_term_field_data']['changed_year_month'] = [
            'title' => $this->t('Updated year + month'),
            'help' => $this->t('Date in the form of YYYYMM.'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_year_month',
            ],
        ];
        $data['taxonomy_term_field_data']['changed_year'] = [
            'title' => $this->t('Updated year'),
            'help' => $this->t('Date in the form of YYYY.'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_year',
            ],
        ];
        $data['taxonomy_term_field_data']['changed_month'] = [
            'title' => $this->t('Updated month'),
            'help' => $this->t('Date in the form of MM (01 - 12).'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_month',
            ],
        ];
        $data['taxonomy_term_field_data']['changed_day'] = [
            'title' => $this->t('Updated day'),
            'help' => $this->t('Date in the form of DD (01 - 31).'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_day',
            ],
        ];
        $data['taxonomy_term_field_data']['changed_week'] = [
            'title' => $this->t('Updated week'),
            'help' => $this->t('Date in the form of WW (01 - 53).'),
            'argument' => [
                'field' => 'changed',
                'id' => 'date_week',
            ],
        ];
        $data['taxonomy_index']['table']['group'] = $this->t('Taxonomy term');
        $data['taxonomy_index']['table']['join'] = [
            'taxonomy_term_field_data' => [
                // links directly to taxonomy_term_field_data via tid
'left_field' => 'tid',
                'field' => 'tid',
            ],
            'node_field_data' => [
                // links directly to node via nid
'left_field' => 'nid',
                'field' => 'nid',
            ],
            'taxonomy_term__parent' => [
                'left_field' => 'entity_id',
                'field' => 'tid',
            ],
        ];
        $data['taxonomy_index']['nid'] = [
            'title' => $this->t('Content with term'),
            'help' => $this->t('Relate all content tagged with a term.'),
            'relationship' => [
                'id' => 'standard',
                'base' => 'node_field_data',
                'base field' => 'nid',
                'label' => $this->t('node'),
                'skip base' => 'node_field_data',
            ],
        ];
        // @todo This stuff needs to move to a node field since really it's all
        //   about nodes.
        $data['taxonomy_index']['tid'] = [
            'group' => $this->t('Content'),
            'title' => $this->t('Has taxonomy term ID'),
            'help' => $this->t('Display content if it has the selected taxonomy terms.'),
            'argument' => [
                'id' => 'taxonomy_index_tid',
                'name table' => 'taxonomy_term_field_data',
                'name field' => 'name',
                'empty field name' => $this->t('Uncategorized'),
                'numeric' => TRUE,
                'skip base' => 'taxonomy_term_field_data',
            ],
            'filter' => [
                'title' => $this->t('Has taxonomy term'),
                'id' => 'taxonomy_index_tid',
                'hierarchy table' => 'taxonomy_term__parent',
                'numeric' => TRUE,
                'skip base' => 'taxonomy_term_field_data',
                'allow empty' => TRUE,
            ],
        ];
        $data['taxonomy_index']['status'] = [
            'title' => $this->t('Publish status'),
            'help' => $this->t('Whether or not the content related to a term is published.'),
            'filter' => [
                'id' => 'boolean',
                'label' => $this->t('Published status'),
                'type' => 'yes-no',
            ],
        ];
        $data['taxonomy_index']['sticky'] = [
            'title' => $this->t('Sticky status'),
            'help' => $this->t('Whether or not the content related to a term is sticky.'),
            'filter' => [
                'id' => 'boolean',
                'label' => $this->t('Sticky status'),
                'type' => 'yes-no',
            ],
            'sort' => [
                'id' => 'standard',
                'help' => $this->t('Whether or not the content related to a term is sticky. To list sticky content first, set this to descending.'),
            ],
        ];
        $data['taxonomy_index']['created'] = [
            'title' => $this->t('Post date'),
            'help' => $this->t('The date the content related to a term was posted.'),
            'sort' => [
                'id' => 'date',
            ],
            'filter' => [
                'id' => 'date',
            ],
        ];
        // Link to self through left.parent = right.tid (going down in depth).
        $data['taxonomy_term__parent']['table']['join']['taxonomy_term__parent'] = [
            'left_field' => 'entity_id',
            'field' => 'parent_target_id',
        ];
        $data['taxonomy_term__parent']['parent_target_id']['help'] = $this->t('The parent term of the term. This can produce duplicate entries if you are using a vocabulary that allows multiple parents.');
        $data['taxonomy_term__parent']['parent_target_id']['relationship']['label'] = $this->t('Parent');
        $data['taxonomy_term__parent']['parent_target_id']['argument']['id'] = 'taxonomy';
        return $data;
    }

}