New sensor: Requirements recap

I've implemented one of the MR comments. Thanks @jjchinquist for review.

I've added html decoding. Thanks for review and testing, @fago.

@fago Thank you for your comment. I've implemented it.

I've implemented plugin selection in configuration form. It requires some not so nice detour for storing plugins so I am setting this issue state as needs review again.

The problem was that some plugin ids have dot in their id and that is invalid character to store in configuration so I've replaced dots with double underscore

  protected function getAllRequirements() {
    $requirements = $this->systemManager->listRequirements();
    $all_requirements = [];
    foreach ($requirements as $id => $requirement) {
      if (strpos($id, '.') !== FALSE) {
        $id = str_replace('.', '__', $id);
      }
      $all_requirements[$id] = is_string($requirement['title']) ? $requirement['title'] : $requirement['title']->__toString();
    }
    return $all_requirements;
  }

and then convert underscore back to dot again:

  public function runSensor(SensorResultInterface $sensor_result) {
    $severity = (int) $this->sensorConfig->getSetting('severity');
    $enabled_requirements = $this->sensorConfig->getSetting('requirements');
    // Configuration keys can't have dots in them and are replaced with `__`.
    array_walk($enabled_requirements, function (&$val) {
      $val = str_replace('.', '__', $val);
    });
    $requirements = array_intersect_key($this->systemManager->listRequirements(), array_flip($enabled_requirements));
    $requirements = array_filter($requirements, function ($requirement) use ($severity) {
      return isset($requirement['severity']) && $requirement['severity'] === $severity;
    });

Does anyone have a better idea/solution?

@fago Thanks for your response! I've implemented the code you suggest.

I have to add some error checking in the code:

The website encountered an unexpected error. Please try again later.
TypeError: array_walk(): Argument #1 ($array) must be of type array, null given in array_walk() (line 49 of modules/contrib/monitoring/src/Plugin/monitoring/SensorPlugin/RequirementsRecapSensorPlugin.php).

array_walk(NULL, Object) (Line: 49)
Drupal\monitoring\Plugin\monitoring\SensorPlugin\RequirementsRecapSensorPlugin->runSensor(Object) (Line: 175)
Drupal\monitoring\SensorRunner->runSensor(Object) (Line: 135)
Drupal\monitoring\SensorRunner->runSensors() (Line: 117)
Drupal\ohdear_integration\OhdearHealthcheckGenerator->getData() (Line: 79)

Error won't happen again.

@berdir, thank you for code review.
I've implemented caching, improved disabled sensor config and added update and cron to default values (and tested that everything still works).

I've improved caching and "improved" status message output as well.

I've tried to have html in the status messages in monitoring report, but this was simply to hard to achieve, because html is escaped in sensor list. Html still shows up in detailed view.

@berdir would you care to check my implementation of your comments? I'm not sure about the caching part.

Hello.
Any chance of getting this ticket reviewed?

I've fixed this phpcs issue.