Use alias manager and storage services instead of custom queries against url_alias

The problem is that we already have deleteAll(). deleteAll() and deleteAllAliases() doing something different wouldn't make sense.

What we could do is rename the current deleteAll() to deleteBySourcePrefix() because that's what it does and then have deleteAll() actually delete all.

1. +++ b/src/AliasStorageHelper.php
   @@ -155,40 +155,27 @@ class AliasStorageHelper implements AliasStorageHelperInterface {
      public function loadBySource($source, $language = LanguageInterface::LANGCODE_NOT_SPECIFIED) {
   -    // @todo convert this to be a query on alias storage.
   -    $pid = $this->database->queryRange("SELECT pid FROM {url_alias} WHERE source = :source AND langcode IN (:language, :language_none) ORDER BY langcode DESC, pid DESC", 0, 1, array(
   -      ':source' => $source,
   -      ':language' => $language,
   -      ':language_none' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
   -    ))->fetchField();
   -    return $this->aliasStorage->load(array('pid' => $pid));
   +    return $this->aliasStorage->load([
   +      'source' => $source,
   +      'langcode' => $language,
   +    ]);
      }
   

   the behavior with langcode and fallback is important, we can't just remove that. Because that's how the system works when resolving an alias, it first checks the current language then falls back to language-unspecific.

2. +++ b/src/AliasStorageHelper.php
   @@ -223,12 +210,15 @@ class AliasStorageHelper implements AliasStorageHelperInterface {
   +  public function countAliasesBySourcePrefix($source) {
   +    return $this->database->select('url_alias')->condition('source', $source . '%', 'LIKE')->countQuery()->execute()->fetchField();
      }
   

   since the class is called AliasStorageHelper and most methods don't have Alias in the name, I think we should be consistent and always leave it out.

1. +++ b/src/AliasStorageHelper.php
   @@ -182,43 +191,57 @@ class AliasStorageHelper implements AliasStorageHelperInterface {
   +   *
   +   * @param integer[] $pids
   +   *   An array of path IDs to delete.
   

   just int, not integer.

2. +++ b/src/Form/PathautoAdminDelete.php
   @@ -101,12 +101,12 @@ class PathautoAdminDelete extends FormBase {
   -      $storage_helper->deleteAll((string)$alias_type->getSourcePrefix());
   +      $storage_helper->deleteBySourcePrefix((string)$alias_type->getSourcePrefix());
   

   space after (string)

Looks good to me. One thing that I think we should also do here is to add the backend_overridable tag to the storage helper service in services.yml, see https://www.drupal.org/node/2306083. That makes it easier for e.g. redis to provide an alternative backend.

Looks good but waited too long, needs a reroll now.

Thanks, committed.