DataListCountIs.php

<?php

namespace Drupal\rules\Plugin\Condition;

use Drupal\rules\Core\RulesConditionBase;

/**
 * Provides a 'List count comparison' condition.
 *
 * @todo Add access callback information from Drupal 7?
 *
 * @Condition(
 *   id = "rules_list_count_is",
 *   label = @Translation("List count comparison"),
 *   category = @Translation("Data"),
 *   context_definitions = {
 *     "list" = @ContextDefinition("list",
 *       label = @Translation("List"),
 *       description = @Translation("A multi-valued data element to have its count compared, specified by using a data selector, eg 'node.uid.entity.roles'."),
 *       assignment_restriction = "selector"
 *     ),
 *     "operator" = @ContextDefinition("string",
 *       label = @Translation("Operator"),
 *       description = @Translation("The comparison operator."),
 *       options_provider = "\Drupal\rules\TypedData\Options\ComparisonOperatorNumericOptions",
 *       assignment_restriction = "input",
 *       default_value = "==",
 *       required = FALSE
 *     ),
 *     "value" = @ContextDefinition("integer",
 *       label = @Translation("Count"),
 *       description = @Translation("The count to compare the data count with.")
 *     ),
 *   }
 * )
 */
class DataListCountIs extends RulesConditionBase {
    
    /**
     * Compare the value to the count of the list.
     *
     * @param array $list
     *   The list to compare the value to.
     * @param string $operator
     *   The type of comparison to do, may be one of '==', '<', or '>'.
     * @param int $value
     *   The value of that the count is to compare to.
     *
     * @return bool
     *   TRUE if the comparison returns true.
     */
    protected function doEvaluate(array $list, $operator, $value) {
        switch ($operator) {
            case '==':
                return count($list) == $value;
            case '<':
                return count($list) < $value;
            case '<=':
                return count($list) <= $value;
            case '>':
                return count($list) > $value;
            case '>=':
                return count($list) >= $value;
        }
    }

}