Custom views filter

Question

In Drupal 8, I have a view that gathers all the nodes built in my Gallery Hours content type. The content type has a field called View Order that I use for another view that displays the list of gallery hours in that order. What I am trying to do is to build another view that checks for the gallery hours for today. For instance, today is Tuesday, so I would like the view to display the gallery hours for Tuesday.

My thought was to create a custom filter option that compares the numeric value of a field, such as my View Order field which is set to 1=Sunday, 2=Monday, etc., with DATE_FORMAT(NOW(),"%N"). This is my first foray into custom Drupal module development and am spinning my wheels. Any and all suggestions welcome.

The one thing I think I have correct are my yaml files.

todaysdate.info.yml

name: Todays Date Filter module
description: 'Creates a filter to search by todays day of the week.'
type: module
core: 8.x
package: SMA Modules

todaysdate.routing.yml

todaysdate:
  defaults:
    _controller: Drupal\todaysdate\Plugin\Filter\todays_date_handler_filter_numeric::operators
  requirements:
    _permission: 'access content'

Where I am really confused is where to go from there. I am trying to piece together a class that extends the NumericFilter and add a new operator that then add to the WHERE expression with the dateformat I'm looking for.

Anyhoo, this is my attempt at creating the filter. I am not getting any errors, but I am also not getting the new operator on my numeric fields in my view.

todays_date_handler_filter_numeric.php

<?php

/**
 * @file
 * Provides views filter option for the Todays Date module.
 */

namespace Drupal\todaysdate\Plugin\Filter;

use Drupal\views\Plugin\views\display\DisplayPluginBase;
use Drupal\views\Plugin\views\filter\NumericFilter;
use Drupal\views\Plugin\views\filter\InOperator;

class todays_date_handler_filter_numeric extends NumericFilter {
  function operators(){
    $operators = parent::operators();
    $operators += array(
      'todays date' => array(
        'title' => $this->t('Is this day of the week'),
        'short' => $this->t('todays date'),
        'method' => 'op_day_of_week',
        'values' => 0,
      )
    );
    return $operators;

    function op_day_of_week($field) {
      $this->query->addWhereExpression($this->options['group'], 'DATE_FORMAT(NOW(),"%N")');
    }
  }
}

Thank you all in advance for any assistance you can provide. I can't tell you how many times StackOverflow has helped me in the past.

Answer 1

You should register your custom filter in both mymodule.views.inc and in the class annotations.

\Drupal\mymodule\Plugin\views\filter\MyCustomNumericFilter

<?php

namespace Drupal\mymodule\Plugin\views\filter;

use Drupal\views\Plugin\views\filter\NumericFilter;

/**
 * My custom numeric filter.
 *
 * @ingroup views_filter_handlers
 *
 * @ViewsFilter("my_custom_numeric_filter")
 */
class MyCustomNumericFilter extends NumericFilter {

  public function query() {   
    $this->query->addWhereExpression($this->options['group'], 'DATE_FORMAT(NOW(),"%N")');
  }

  protected function operators() {
    $operators = parent::operators();
    $operators += array(
      'todays date' => array(
        'title' => $this->t('Is this day of the week'),
        'short' => $this->t('todays date'),
        'method' => 'op_day_of_week',
        'values' => 0,
      )
    );
    return $operators;
  }

}

mymodule.views.inc (placed in custom module root)

function mymodule_views_data() {
  $data = [];
  $data['views']['my_custom_numeric_filter'] = [
    'title' => t('My custom numeric filter'),
    'filter' => [
      'title' => t('My custom numeric filter'),
      'group' => 'Custom',
      'help' => t('Provides custom numeric filter.'),
      'id' => 'my_custom_numeric_filter'
    ],
  ];
  return $data; 
}

I moved your custom query expression (without checking) to the query() method since Views calls this method on filtering.

Let me know if this works for you.