1<?php
2
3namespace Drupal\Core\Cache\Context;
4
5use Drupal\Core\Cache\CacheableMetadata;
6
7/**
8 * Defines the QueryArgsCacheContext service, for "per query args" caching.
9 *
10 * Cache context ID: 'url.query_args' (to vary by all query arguments).
11 * Calculated cache context ID: 'url.query_args:%key', e.g.'url.query_args:foo'
12 * (to vary by the 'foo' query argument).
13 */
14class QueryArgsCacheContext extends RequestStackCacheContextBase implements CalculatedCacheContextInterface {
15
16  /**
17   * {@inheritdoc}
18   */
19  public static function getLabel() {
20    return t('Query arguments');
21  }
22
23  /**
24   * {@inheritdoc}
25   */
26  public function getContext($query_arg = NULL) {
27    if ($query_arg === NULL) {
28      // All arguments requested. Use normalized query string to minimize
29      // variations.
30      $value = $this->requestStack->getCurrentRequest()->getQueryString();
31      return ($value !== NULL) ? $value : '';
32    }
33    elseif ($this->requestStack->getCurrentRequest()->query->has($query_arg)) {
34      $value = $this->requestStack->getCurrentRequest()->query->get($query_arg);
35      if (is_array($value)) {
36        return http_build_query($value);
37      }
38      elseif ($value !== '') {
39        return $value;
40      }
41      return '?valueless?';
42    }
43    return '';
44  }
45
46  /**
47   * {@inheritdoc}
48   */
49  public function getCacheableMetadata($query_arg = NULL) {
50    return new CacheableMetadata();
51  }
52
53}
54