ZF\Apigility\Doctrine\Admin\Model\DoctrineAutodiscoveryModel::fetchFields PHP Method

    public function fetchFields($module, $version, $adapterName)
    {
        $entities = [];
        /**
         * @var ObjectManager $em
         */
        $em = $this->getServiceLocator()->get($adapterName);
        /**
         * @var AbstractClassMetadataFactory $cmf
         */
        $cmf = $em->getMetadataFactory();
        /**
         * @var ClassMetadata $classMetadata
         */
        foreach ($cmf->getAllMetadata() as $classMetadata) {
            $service = substr($classMetadata->getName(), strrpos($classMetadata->getName(), '\\') + 1);
            if ($this->moduleHasService($module, $version, $service)) {
                continue;
            }
            $entity = ['entity_class' => $classMetadata->getName(), 'service_name' => $service, 'fields' => []];
            foreach ($classMetadata->fieldMappings as $mapping) {
                if ($classMetadata->isIdentifier($mapping['fieldName'])) {
                    continue;
                }
                $field = ['name' => $mapping['fieldName'], 'required' => !isset($mapping['nullable']) || $mapping['nullable'] !== true, 'filters' => [], 'validators' => []];
                switch ($mapping['type']) {
                    case 'string':
                        $field['filters'] = $this->filters['text'];
                        if (!empty($mapping['length'])) {
                            $validator = $this->validators['text'];
                            $validator['options']['max'] = $mapping['length'];
                            $field['validators'][] = $validator;
                        }
                        break;
                    case 'integer':
                    case 'int':
                        $field['filters'] = $this->filters['integer'];
                        break;
                    default:
                        continue;
                        break;
                }
                $entity['fields'][] = $field;
            }
            $entities[] = $entity;
        }
        return $entities;
    }

 public function discoverAction()
 {
     $module = $this->params()->fromRoute('name');
     $version = $this->params()->fromRoute('version');
     $adapter = $this->params()->fromRoute('object_manager_alias');
     $data = $this->model->fetchFields($module, $version, $adapter);
     return new ViewModel(array('payload' => $data));
 }