diff --git a/Classes/Command/HarvestCommand.php b/Classes/Command/HarvestCommand.php
index f4ae394f7..5ddb9edc2 100644
--- a/Classes/Command/HarvestCommand.php
+++ b/Classes/Command/HarvestCommand.php
@@ -127,15 +127,15 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             }
             // Abort if solrCoreUid is empty or not in the array of allowed solr cores.
             if (empty($solrCoreUid) || !in_array($solrCoreUid, $allSolrCores)) {
-                $output_solrCores = [];
-                foreach ($allSolrCores as $index_name => $uid) {
-                    $output_solrCores[] = $uid . ' : ' . $index_name;
+                $outputSolrCores = [];
+                foreach ($allSolrCores as $indexName => $uid) {
+                    $outputSolrCores[] = $uid . ' : ' . $indexName;
                 }
-                if (empty($output_solrCores)) {
+                if (empty($outputSolrCores)) {
                     $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. No valid cores found on PID ' . $this->storagePid . ".\n");
                     return BaseCommand::FAILURE;
                 } else {
-                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $output_solrCores) . "\n");
+                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $outputSolrCores) . "\n");
                     return BaseCommand::FAILURE;
                 }
             }
diff --git a/Classes/Command/IndexCommand.php b/Classes/Command/IndexCommand.php
index 6120b0ed8..1a392e2e1 100644
--- a/Classes/Command/IndexCommand.php
+++ b/Classes/Command/IndexCommand.php
@@ -111,15 +111,15 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
             // Abort if solrCoreUid is empty or not in the array of allowed solr cores.
             if (empty($solrCoreUid) || !in_array($solrCoreUid, $allSolrCores)) {
-                $output_solrCores = [];
-                foreach ($allSolrCores as $index_name => $uid) {
-                    $output_solrCores[] = $uid . ' : ' . $index_name;
+                $outputSolrCores = [];
+                foreach ($allSolrCores as $indexName => $uid) {
+                    $outputSolrCores[] = $uid . ' : ' . $indexName;
                 }
-                if (empty($output_solrCores)) {
+                if (empty($outputSolrCores)) {
                     $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. No valid cores found on PID ' . $this->storagePid . ".\n");
                     return BaseCommand::FAILURE;
                 } else {
-                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $output_solrCores) . "\n");
+                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $outputSolrCores) . "\n");
                     return BaseCommand::FAILURE;
                 }
             }
diff --git a/Classes/Command/ReindexCommand.php b/Classes/Command/ReindexCommand.php
index 177cf923c..828c26c37 100644
--- a/Classes/Command/ReindexCommand.php
+++ b/Classes/Command/ReindexCommand.php
@@ -127,15 +127,15 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
             // Abort if solrCoreUid is empty or not in the array of allowed solr cores.
             if (empty($solrCoreUid) || !in_array($solrCoreUid, $allSolrCores)) {
-                $output_solrCores = [];
-                foreach ($allSolrCores as $index_name => $uid) {
-                    $output_solrCores[] = $uid . ' : ' . $index_name;
+                $outputSolrCores = [];
+                foreach ($allSolrCores as $indexName => $uid) {
+                    $outputSolrCores[] = $uid . ' : ' . $indexName;
                 }
-                if (empty($output_solrCores)) {
+                if (empty($outputSolrCores)) {
                     $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. No valid cores found on PID ' . $this->storagePid . ".\n");
                     return BaseCommand::FAILURE;
                 } else {
-                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $output_solrCores) . "\n");
+                    $io->error('ERROR: No valid Solr core ("' . $input->getOption('solr') . '") given. ' . "Valid cores are (<uid>:<index_name>):\n" . implode("\n", $outputSolrCores) . "\n");
                     return BaseCommand::FAILURE;
                 }
             }
diff --git a/Classes/Common/Helper.php b/Classes/Common/Helper.php
index 8ca41ea5a..4a5a76182 100644
--- a/Classes/Common/Helper.php
+++ b/Classes/Common/Helper.php
@@ -12,6 +12,7 @@
 
 namespace Kitodo\Dlf\Common;
 
+use TYPO3\CMS\Core\Configuration\ConfigurationManager;
 use TYPO3\CMS\Core\Configuration\ExtensionConfiguration;
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Http\Uri;
@@ -207,7 +208,7 @@ public static function decrypt(string $encrypted)
             self::log('OpenSSL library doesn\'t support cipher and/or hash algorithm', LOG_SEVERITY_ERROR);
             return false;
         }
-        if (empty($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'])) {
+        if (empty(self::getEncryptionKey())) {
             self::log('No encryption key set in TYPO3 configuration', LOG_SEVERITY_ERROR);
             return false;
         }
@@ -222,7 +223,7 @@ public static function decrypt(string $encrypted)
         $binary = base64_decode($encrypted);
         $iv = substr($binary, 0, openssl_cipher_iv_length(self::$cipherAlgorithm));
         $data = substr($binary, openssl_cipher_iv_length(self::$cipherAlgorithm));
-        $key = openssl_digest($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'], self::$hashAlgorithm, true);
+        $key = openssl_digest(self::getEncryptionKey(), self::$hashAlgorithm, true);
         // Decrypt data.
         return openssl_decrypt($data, self::$cipherAlgorithm, $key, OPENSSL_RAW_DATA, $iv);
     }
@@ -342,13 +343,13 @@ public static function encrypt(string $string)
             self::log('OpenSSL library doesn\'t support cipher and/or hash algorithm', LOG_SEVERITY_ERROR);
             return false;
         }
-        if (empty($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'])) {
+        if (empty(self::getEncryptionKey())) {
             self::log('No encryption key set in TYPO3 configuration', LOG_SEVERITY_ERROR);
             return false;
         }
         // Generate random initialization vector.
         $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length(self::$cipherAlgorithm));
-        $key = openssl_digest($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'], self::$hashAlgorithm, true);
+        $key = openssl_digest(self::getEncryptionKey(), self::$hashAlgorithm, true);
         // Encrypt data.
         $encrypted = openssl_encrypt($string, self::$cipherAlgorithm, $key, OPENSSL_RAW_DATA, $iv);
         // Merge initialization vector and encrypted data.
@@ -358,23 +359,6 @@ public static function encrypt(string $string)
         return $encrypted;
     }
 
-    /**
-     * Get the unqualified name of a class
-     *
-     * @access public
-     *
-     * @static
-     *
-     * @param string $qualifiedClassName The qualified class name from get_class()
-     *
-     * @return string The unqualified class name
-     */
-    public static function getUnqualifiedClassName(string $qualifiedClassName): string
-    {
-        $nameParts = explode('\\', $qualifiedClassName);
-        return end($nameParts);
-    }
-
     /**
      * Clean up a string to use in an URL.
      *
@@ -412,8 +396,8 @@ public static function getCleanString(string $string): string
     public static function getHookObjects(string $scriptRelPath): array
     {
         $hookObjects = [];
-        if (is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS'][self::$extKey . '/' . $scriptRelPath]['hookClass'])) {
-            foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS'][self::$extKey . '/' . $scriptRelPath]['hookClass'] as $classRef) {
+        if (is_array(self::getOptions()[self::$extKey . '/' . $scriptRelPath]['hookClass'])) {
+            foreach (self::getOptions()[self::$extKey . '/' . $scriptRelPath]['hookClass'] as $classRef) {
                 $hookObjects[] = GeneralUtility::makeInstance($classRef);
             }
         }
@@ -556,94 +540,6 @@ public static function getDocumentStructures(int $pid = -1): array
         return array_column($allStructures, 'indexName', 'uid');
     }
 
-    /**
-     * Get the URN of an object
-     * @see http://www.persistent-identifier.de/?link=316
-     *
-     * @access public
-     *
-     * @static
-     *
-     * @param string $base The namespace and base URN
-     * @param string $id The object's identifier
-     *
-     * @return string Uniform Resource Name as string
-     */
-    public static function getURN(string $base, string $id): string
-    {
-        $concordance = [
-            '0' => 1,
-            '1' => 2,
-            '2' => 3,
-            '3' => 4,
-            '4' => 5,
-            '5' => 6,
-            '6' => 7,
-            '7' => 8,
-            '8' => 9,
-            '9' => 41,
-            'a' => 18,
-            'b' => 14,
-            'c' => 19,
-            'd' => 15,
-            'e' => 16,
-            'f' => 21,
-            'g' => 22,
-            'h' => 23,
-            'i' => 24,
-            'j' => 25,
-            'k' => 42,
-            'l' => 26,
-            'm' => 27,
-            'n' => 13,
-            'o' => 28,
-            'p' => 29,
-            'q' => 31,
-            'r' => 12,
-            's' => 32,
-            't' => 33,
-            'u' => 11,
-            'v' => 34,
-            'w' => 35,
-            'x' => 36,
-            'y' => 37,
-            'z' => 38,
-            '-' => 39,
-            ':' => 17,
-        ];
-        $urn = strtolower($base . $id);
-        if (preg_match('/[^a-z\d:-]/', $urn)) {
-            self::log('Invalid chars in given parameters', LOG_SEVERITY_WARNING);
-            return '';
-        }
-        $digits = '';
-        for ($i = 0, $j = strlen($urn); $i < $j; $i++) {
-            $digits .= $concordance[substr($urn, $i, 1)];
-        }
-        $checksum = 0;
-        for ($i = 0, $j = strlen($digits); $i < $j; $i++) {
-            $checksum += ($i + 1) * (int) substr($digits, $i, 1);
-        }
-        $checksum = substr((string) floor($checksum / (int) substr($digits, -1, 1)), -1, 1);
-        return $base . $id . $checksum;
-    }
-
-    /**
-     * Check if given ID is a valid Pica Production Number (PPN)
-     *
-     * @access public
-     *
-     * @static
-     *
-     * @param string $id The identifier to check
-     *
-     * @return bool Is $id a valid PPN?
-     */
-    public static function isPPN(string $id): bool
-    {
-        return self::checkIdentifier($id, 'PPN');
-    }
-
     /**
      * Determine whether or not $url is a valid URL using HTTP or HTTPS scheme.
      *
@@ -670,28 +566,6 @@ public static function isValidHttpUrl(string $url): bool
         }
     }
 
-    /**
-     * Merges two arrays recursively and actually returns the modified array.
-     * @see ArrayUtility::mergeRecursiveWithOverrule()
-     *
-     * @access public
-     *
-     * @static
-     *
-     * @param array $original Original array
-     * @param array $overrule Overrule array, overruling the original array
-     * @param bool $addKeys If set to false, keys that are not found in $original will not be set
-     * @param bool $includeEmptyValues If set, values from $overrule will overrule if they are empty
-     * @param bool $enableUnsetFeature If set, special value "__UNSET" can be used in the overrule array to unset keys in the original array
-     *
-     * @return array Merged array
-     */
-    public static function mergeRecursiveWithOverrule(array $original, array $overrule, bool $addKeys = true, bool $includeEmptyValues = true, bool $enableUnsetFeature = true): array
-    {
-        ArrayUtility::mergeRecursiveWithOverrule($original, $overrule, $addKeys, $includeEmptyValues, $enableUnsetFeature);
-        return $original;
-    }
-
     /**
      * Process a data and/or command map with TYPO3 core engine as admin.
      *
@@ -1018,4 +892,49 @@ public static function isValidXmlId($id): bool
     {
         return preg_match('/^[_a-z][_a-z0-9-.]*$/i', $id) === 1;
     }
+
+    /**
+     * Get options from local configuration.
+     *
+     * @access private
+     *
+     * @static
+     *
+     * @return array
+     */
+    private static function getOptions(): array
+    {
+        return self::getLocalConfigurationByPath('SC_OPTIONS');
+    }
+
+    /**
+     * Get encryption key from local configuration.
+     *
+     * @access private
+     *
+     * @static
+     *
+     * @return string|null
+     */
+    private static function getEncryptionKey(): ?string
+    {
+        return self::getLocalConfigurationByPath('SYS/encryptionKey');
+    }
+
+    /**
+     * Get local configuration for given path.
+     *
+     * @access private
+     *
+     * @static
+     * 
+     * @param string $path
+     *
+     * @return mixed
+     */
+    private static function getLocalConfigurationByPath(string $path)
+    {
+        $configurationManager = GeneralUtility::makeInstance(ConfigurationManager::class);
+        return $configurationManager->getLocalConfigurationValueByPath($path);
+    }
 }
diff --git a/Classes/Common/MetsDocument.php b/Classes/Common/MetsDocument.php
index 31f1ab50e..455d7343a 100644
--- a/Classes/Common/MetsDocument.php
+++ b/Classes/Common/MetsDocument.php
@@ -12,6 +12,9 @@
 
 namespace Kitodo\Dlf\Common;
 
+use \DOMElement;
+use \DOMXPath;
+use \SimpleXMLElement;
 use TYPO3\CMS\Core\Configuration\ExtensionConfiguration;
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Database\Query\Restriction\HiddenRestriction;
@@ -57,14 +60,14 @@
  * @property-read string $thumbnail this holds the document's thumbnail location
  * @property bool $thumbnailLoaded flag with information if the thumbnail is loaded
  * @property-read string $toplevelId this holds the toplevel structure's "@ID" (METS) or the manifest's "@id" (IIIF)
- * @property \SimpleXMLElement $xml this holds the whole XML file as \SimpleXMLElement object
+ * @property SimpleXMLElement $xml this holds the whole XML file as SimpleXMLElement object
  * @property-read array $mdSec associative array of METS metadata sections indexed by their IDs.
  * @property bool $mdSecLoaded flag with information if the array of METS metadata sections is loaded
  * @property-read array $dmdSec subset of `$mdSec` storing only the dmdSec entries; kept for compatibility.
  * @property-read array $fileGrps this holds the file ID -> USE concordance
  * @property bool $fileGrpsLoaded flag with information if file groups array is loaded
  * @property-read array $fileInfos additional information about files (e.g., ADMID), indexed by ID.
- * @property-read \SimpleXMLElement $mets this holds the XML file's METS part as \SimpleXMLElement object
+ * @property-read SimpleXMLElement $mets this holds the XML file's METS part as SimpleXMLElement object
  * @property-read string $parentHref URL of the parent document (determined via mptr element), or empty string if none is available
  */
 final class MetsDocument extends AbstractDocument
@@ -130,9 +133,9 @@ final class MetsDocument extends AbstractDocument
 
     /**
      * @access protected
-     * @var \SimpleXMLElement This holds the XML file's METS part as \SimpleXMLElement object
+     * @var SimpleXMLElement This holds the XML file's METS part as SimpleXMLElement object
      */
-    protected \SimpleXMLElement $mets;
+    protected SimpleXMLElement $mets;
 
     /**
      * @access protected
@@ -352,12 +355,12 @@ public function getLogicalStructure(string $id, bool $recursive = false): array
      *
      * @access protected
      *
-     * @param \SimpleXMLElement $structure The logical structure node
+     * @param SimpleXMLElement $structure The logical structure node
      * @param bool $recursive Whether to include the child elements
      *
      * @return array Array of the element's id, label, type and physical page indexes/mptr link
      */
-    protected function getLogicalStructureInfo(\SimpleXMLElement $structure, bool $recursive = false): array
+    protected function getLogicalStructureInfo(SimpleXMLElement $structure, bool $recursive = false): array
     {
         $attributes = $structure->attributes();
 
@@ -396,11 +399,61 @@ protected function getLogicalStructureInfo(\SimpleXMLElement $structure, bool $r
         $this->magicGetSmLinks();
         // Load physical structure.
         $this->magicGetPhysicalStructure();
-        // Get the physical page or external file this structure element is pointing at.
-        // Is there a mptr node?
-        if (count($structure->children('http://www.loc.gov/METS/')->mptr)) {
+
+        $this->getPage($details, $structure->children('http://www.loc.gov/METS/')->mptr);
+        $this->getFiles($details, $structure->children('http://www.loc.gov/METS/')->fptr);
+
+        // Keep for later usage.
+        $this->logicalUnits[$details['id']] = $details;
+        // Walk the structure recursively? And are there any children of the current element?
+        if (
+            $recursive
+            && count($structure->children('http://www.loc.gov/METS/')->div)
+        ) {
+            $details['children'] = [];
+            foreach ($structure->children('http://www.loc.gov/METS/')->div as $child) {
+                // Repeat for all children.
+                $details['children'][] = $this->getLogicalStructureInfo($child, true);
+            }
+        }
+        return $details;
+    }
+
+    /**
+     * Get the files this structure element is pointing at.
+     *
+     * @param ?SimpleXMLElement $filePointers
+     *
+     * @return void
+     */
+    private function getFiles(array &$details, ?SimpleXMLElement $filePointers): void
+    {
+        $fileUse = $this->magicGetFileGrps();
+        // Get the file representations from fileSec node.
+        foreach ($filePointers as $filePointer) {
+            $fileId = (string) $filePointer->attributes()->FILEID;
+            // Check if file has valid @USE attribute.
+            if (!empty($fileUse[$fileId])) {
+                $details['files'][$fileUse[$fileId]] = $fileId;
+            }
+        }
+    }
+
+    /**
+     * Get the physical page or external file this structure element is pointing at.
+     *
+     * @access private
+     *
+     * @param array $details passed as reference
+     * @param ?SimpleXMLElement $metsPointers
+     *
+     * @return void
+     */
+    private function getPage(array &$details, ?SimpleXMLElement $metsPointers): void
+    {
+        if (count($metsPointers)) {
             // Yes. Get the file reference.
-            $details['points'] = (string) $structure->children('http://www.loc.gov/METS/')->mptr[0]->attributes('http://www.w3.org/1999/xlink')->href;
+            $details['points'] = (string) $metsPointers[0]->attributes('http://www.w3.org/1999/xlink')->href;
         } elseif (
             !empty($this->physicalStructure)
             && array_key_exists($details['id'], $this->smLinks['l2p'])
@@ -418,29 +471,6 @@ protected function getLogicalStructureInfo(\SimpleXMLElement $structure, bool $r
         if ($details['thumbnailId'] === null) {
             unset($details['thumbnailId']);
         }
-        // Get the files this structure element is pointing at.
-        $fileUse = $this->magicGetFileGrps();
-        // Get the file representations from fileSec node.
-        foreach ($structure->children('http://www.loc.gov/METS/')->fptr as $fptr) {
-            // Check if file has valid @USE attribute.
-            if (!empty($fileUse[(string) $fptr->attributes()->FILEID])) {
-                $details['files'][$fileUse[(string) $fptr->attributes()->FILEID]] = (string) $fptr->attributes()->FILEID;
-            }
-        }
-        // Keep for later usage.
-        $this->logicalUnits[$details['id']] = $details;
-        // Walk the structure recursively? And are there any children of the current element?
-        if (
-            $recursive
-            && count($structure->children('http://www.loc.gov/METS/')->div)
-        ) {
-            $details['children'] = [];
-            foreach ($structure->children('http://www.loc.gov/METS/')->div as $child) {
-                // Repeat for all children.
-                $details['children'][] = $this->getLogicalStructureInfo($child, true);
-            }
-        }
-        return $details;
     }
 
     /**
@@ -557,8 +587,8 @@ private function processMetadataSections(string $id, int $cPid, array $metadata)
             // There is no metadata section for this structure node.
             return [];
         }
-        // Associative array used as set of available section types (dmdSec, techMD, ...)
-        $hasMetadataSection = [];
+        // Array used as set of available section types (dmdSec, techMD, ...)
+        $metadataSections = [];
         // Load available metadata formats and metadata sections.
         $this->loadFormats();
         $this->magicGetMdSec();
@@ -568,19 +598,19 @@ private function processMetadataSections(string $id, int $cPid, array $metadata)
         foreach ($mdIds as $dmdId) {
             $mdSectionType = $this->mdSec[$dmdId]['section'];
 
-            if ($mdSectionType === 'dmdSec' && isset($hasMetadataSection['dmdSec'])) {
+            if ($this->hasMetadataSection($metadataSections, $mdSectionType, 'dmdSec')) {
                 continue;
             }
 
-            if (!$this->extractAndProcessMetadata($dmdId, $mdSectionType, $metadata, $cPid, $hasMetadataSection)) {
+            if (!$this->extractAndProcessMetadata($dmdId, $mdSectionType, $metadata, $cPid, $metadataSections)) {
                 continue;
             }
 
-            $hasMetadataSection[$mdSectionType] = true;
+            $metadataSections[] = $mdSectionType;
         }
 
         // Files are not expected to reference a dmdSec
-        if (isset($this->fileInfos[$id]) || isset($hasMetadataSection['dmdSec'])) {
+        if (isset($this->fileInfos[$id]) || in_array('dmdSec', $metadataSections)) {
             return $metadata;
         } else {
             $this->logger->warning('No supported descriptive metadata found for logical structure with @ID "' . $id . '"');
@@ -619,13 +649,13 @@ private function getLogicalUnitType(string $id): array
      * @param string $mdSectionType
      * @param array $metadata
      * @param integer $cPid
-     * @param array $hasMetadataSection
+     * @param array $metadataSections
      *
      * @return boolean
      */
-    private function extractAndProcessMetadata(string $dmdId, string $mdSectionType, array &$metadata, int $cPid, array $hasMetadataSection): bool
+    private function extractAndProcessMetadata(string $dmdId, string $mdSectionType, array &$metadata, int $cPid, array $metadataSections): bool
     {
-        if ($mdSectionType === 'dmdSec' && isset($hasMetadataSection['dmdSec'])) {
+        if ($this->hasMetadataSection($metadataSections, $mdSectionType, 'dmdSec')) {
             return true;
         }
 
@@ -638,7 +668,7 @@ private function extractAndProcessMetadata(string $dmdId, string $mdSectionType,
         $additionalMetadata = $this->getAdditionalMetadataFromDatabase($cPid, $dmdId);
         // We need a \DOMDocument here, because SimpleXML doesn't support XPath functions properly.
         $domNode = dom_import_simplexml($this->mdSec[$dmdId]['xml']);
-        $domXPath = new \DOMXPath($domNode->ownerDocument);
+        $domXPath = new DOMXPath($domNode->ownerDocument);
         $this->registerNamespaces($domXPath);
 
         $this->processAdditionalMetadata($additionalMetadata, $domXPath, $domNode, $metadata);
@@ -646,19 +676,35 @@ private function extractAndProcessMetadata(string $dmdId, string $mdSectionType,
         return true;
     }
 
+    /**
+     * Check if searched metadata section is stored in the array.
+     *
+     * @access private
+     *
+     * @param array $metadataSections
+     * @param string $currentMetadataSection
+     * @param string $searchedMetadataSection
+     *
+     * @return boolean
+     */
+    private function hasMetadataSection(array $metadataSections, string $currentMetadataSection, string $searchedMetadataSection): bool
+    {
+        return $currentMetadataSection === $searchedMetadataSection && in_array($searchedMetadataSection, $metadataSections);
+    }
+
     /**
      * Process additional metadata.
      *
      * @access private
      *
      * @param array $additionalMetadata
-     * @param \DOMXPath $domXPath
-     * @param \DOMElement $domNode
+     * @param DOMXPath $domXPath
+     * @param DOMElement $domNode
      * @param array $metadata
      *
      * @return void
      */
-    private function processAdditionalMetadata(array $additionalMetadata, \DOMXPath $domXPath, \DOMElement $domNode, array &$metadata): void
+    private function processAdditionalMetadata(array $additionalMetadata, DOMXPath $domXPath, DOMElement $domNode, array &$metadata): void
     {
         foreach ($additionalMetadata as $resArray) {
             $this->setMetadataFieldValues($resArray, $domXPath, $domNode, $metadata);
@@ -673,13 +719,13 @@ private function processAdditionalMetadata(array $additionalMetadata, \DOMXPath
      * @access private
      *
      * @param array $resArray
-     * @param \DOMXPath $domXPath
-     * @param \DOMElement $domNode
+     * @param DOMXPath $domXPath
+     * @param DOMElement $domNode
      * @param array $metadata
      *
      * @return void
      */
-    private function setMetadataFieldValues(array $resArray, \DOMXPath $domXPath, \DOMElement $domNode, array &$metadata): void
+    private function setMetadataFieldValues(array $resArray, DOMXPath $domXPath, DOMElement $domNode, array &$metadata): void
     {
         if ($resArray['format'] > 0 && !empty($resArray['xpath'])) {
             $values = $domXPath->evaluate($resArray['xpath'], $domNode);
@@ -717,13 +763,13 @@ private function setDefaultMetadataValue(array $resArray, array &$metadata): voi
      * @access private
      *
      * @param array $resArray
-     * @param \DOMXPath $domXPath
-     * @param \DOMElement $domNode
+     * @param  $domXPath
+     * @param DOMElement $domNode
      * @param array $metadata
      *
      * @return void
      */
-    private function setSortableMetadataValue(array $resArray, \DOMXPath $domXPath, \DOMElement $domNode, array &$metadata): void
+    private function setSortableMetadataValue(array $resArray, DOMXPath $domXPath, DOMElement $domNode, array &$metadata): void
     {
         if (!empty($metadata[$resArray['index_name']]) && $resArray['is_sortable']) {
             if ($resArray['format'] > 0 && !empty($resArray['xpath_sorting'])) {
@@ -1030,7 +1076,7 @@ protected function ensureHasFulltextIsSet(): void
     protected function setPreloadedDocument($preloadedDocument): bool
     {
 
-        if ($preloadedDocument instanceof \SimpleXMLElement) {
+        if ($preloadedDocument instanceof SimpleXMLElement) {
             $this->xml = $preloadedDocument;
             return true;
         }
@@ -1040,7 +1086,7 @@ protected function setPreloadedDocument($preloadedDocument): bool
     /**
      * @see AbstractDocument::getDocument()
      */
-    protected function getDocument(): \SimpleXMLElement
+    protected function getDocument(): SimpleXMLElement
     {
         return $this->mets;
     }
@@ -1113,11 +1159,11 @@ protected function magicGetDmdSec(): array
      *
      * @access protected
      *
-     * @param \SimpleXMLElement $element
+     * @param SimpleXMLElement $element
      *
      * @return array|null The processed metadata section
      */
-    protected function processMdSec(\SimpleXMLElement $element): ?array
+    protected function processMdSec(SimpleXMLElement $element): ?array
     {
         $mdId = (string) $element->attributes()->ID;
         if (empty($mdId)) {
@@ -1232,9 +1278,9 @@ protected function prepareMetadataArray(int $cPid): void
      *
      * @access protected
      *
-     * @return \SimpleXMLElement The XML's METS part as \SimpleXMLElement object
+     * @return SimpleXMLElement The XML's METS part as SimpleXMLElement object
      */
-    protected function magicGetMets(): \SimpleXMLElement
+    protected function magicGetMets(): SimpleXMLElement
     {
         return $this->mets;
     }
@@ -1263,70 +1309,109 @@ protected function magicGetPhysicalStructure(): array
                 $this->physicalStructureInfo[$id]['orderlabel'] = isset($firstNode['ORDERLABEL']) ? (string) $firstNode['ORDERLABEL'] : '';
                 $this->physicalStructureInfo[$id]['type'] = (string) $firstNode['TYPE'];
                 $this->physicalStructureInfo[$id]['contentIds'] = isset($firstNode['CONTENTIDS']) ? (string) $firstNode['CONTENTIDS'] : '';
-                // Get the file representations from fileSec node.
-                foreach ($physNode[0]->children('http://www.loc.gov/METS/')->fptr as $fptr) {
-                    $fileNode = isset($fptr->area)? $fptr->area : $fptr;
 
-                    // Check if file has valid @USE attribute.
-                    if (!empty($fileUse[(string) $fptr->attributes()->FILEID])) {
-                        $this->physicalStructureInfo[$id]['files'][$fileUse[(string) $fptr->attributes()->FILEID]] = (string) $fptr->attributes()->FILEID;
-                    }
+                $this->getFileRepresentation($id, $firstNode);
+
+                $this->physicalStructure = $this->getPhysicalElements($elementNodes, $fileUse);
+            }
+            $this->physicalStructureLoaded = true;
+
+        }
+
+        return $this->physicalStructure;
+    }
+
+    /**
+     * Get the file representations from fileSec node.
+     *
+     * @access private
+     *
+     * @param string $id
+     * @param SimpleXMLElement $physicalNode
+     *
+     * @return void
+     */
+    private function getFileRepresentation(string $id, SimpleXMLElement $physicalNode): void
+    {
+        // Get file groups.
+        $fileUse = $this->magicGetFileGrps();
+
+        foreach ($physicalNode->children('http://www.loc.gov/METS/')->fptr as $fptr) {
+            $fileNode = isset($fptr->area)? $fptr->area : $fptr;
+            $fileId = (string) $fileNode->attributes()->FILEID;
+
+            // Check if file has valid @USE attribute.
+            if (!empty($fileUse[$fileId])) {
+                $this->physicalStructureInfo[$id]['files'][$fileUse[$fileId]] = $fileId;
+            }
+        }
+    }
+
+    /**
+     * Build the physical elements' array from the physical structMap node.
+     *
+     * @access private
+     *
+     * @param array $elementNodes
+     * @param array $fileUse
+     *
+     * @return array
+     */
+    private function getPhysicalElements(array $elementNodes, array $fileUse): array
+    {
+        $elements = [];
+        $id = '';
+
+        foreach ($elementNodes as $elementNode) {
+            $id = (string) $elementNode['ID'];
+            $order = (int) $elementNode['ORDER'];
+            $elements[$order] = $id;
+            $this->physicalStructureInfo[$elements[$order]]['id'] = $id;
+            $this->physicalStructureInfo[$elements[$order]]['dmdId'] = isset($elementNode['DMDID']) ? (string) $elementNode['DMDID'] : '';
+            $this->physicalStructureInfo[$elements[$order]]['admId'] = isset($elementNode['ADMID']) ? (string) $elementNode['ADMID'] : '';
+            $this->physicalStructureInfo[$elements[$order]]['order'] = isset($elementNode['ORDER']) ? (string) $elementNode['ORDER'] : '';
+            $this->physicalStructureInfo[$elements[$order]]['label'] = isset($elementNode['LABEL']) ? (string) $elementNode['LABEL'] : '';
+            $this->physicalStructureInfo[$elements[$order]]['orderlabel'] = isset($elementNode['ORDERLABEL']) ? (string) $elementNode['ORDERLABEL'] : '';
+            $this->physicalStructureInfo[$elements[$order]]['type'] = (string) $elementNode['TYPE'];
+            $this->physicalStructureInfo[$elements[$order]]['contentIds'] = isset($elementNode['CONTENTIDS']) ? (string) $elementNode['CONTENTIDS'] : '';
+            // Get the file representations from fileSec node.
+            foreach ($elementNode->children('http://www.loc.gov/METS/')->fptr as $fptr) {
+                $fileNode = isset($fptr->area)? $fptr->area : $fptr;
+                $fileId = (string) $fileNode->attributes()->FILEID;
+
+                // Check if file has valid @USE attribute.
+                if (!empty($fileUse[(string) $fileId])) {
+                    $this->physicalStructureInfo[$elements[$order]]['files'][$fileUse[$fileId]] = $fileId;
                 }
-                // Build the physical elements' array from the physical structMap node.
-                $elements = [];
-                foreach ($elementNodes as $elementNode) {
-                    $id = (string) $elementNode['ID'];
-                    $order = (int) $elementNode['ORDER'];
-                    $elements[$order] = $id;
-                    $this->physicalStructureInfo[$elements[$order]]['id'] = $id;
-                    $this->physicalStructureInfo[$elements[$order]]['dmdId'] = isset($elementNode['DMDID']) ? (string) $elementNode['DMDID'] : '';
-                    $this->physicalStructureInfo[$elements[$order]]['admId'] = isset($elementNode['ADMID']) ? (string) $elementNode['ADMID'] : '';
-                    $this->physicalStructureInfo[$elements[$order]]['order'] = isset($elementNode['ORDER']) ? (string) $elementNode['ORDER'] : '';
-                    $this->physicalStructureInfo[$elements[$order]]['label'] = isset($elementNode['LABEL']) ? (string) $elementNode['LABEL'] : '';
-                    $this->physicalStructureInfo[$elements[$order]]['orderlabel'] = isset($elementNode['ORDERLABEL']) ? (string) $elementNode['ORDERLABEL'] : '';
-                    $this->physicalStructureInfo[$elements[$order]]['type'] = (string) $elementNode['TYPE'];
-                    $this->physicalStructureInfo[$elements[$order]]['contentIds'] = isset($elementNode['CONTENTIDS']) ? (string) $elementNode['CONTENTIDS'] : '';
-                    // Get the file representations from fileSec node.
-                    foreach ($elementNode->children('http://www.loc.gov/METS/')->fptr as $fptr) {
-                        $fileNode = isset($fptr->area)? $fptr->area : $fptr;
+            }
 
+            // Get track info wtih begin end extent time for later assignment with musical
+            if ((string) $elementNode['TYPE'] === 'track') {
+                foreach ($elementNode->children('http://www.loc.gov/METS/')->fptr as $fptr) {
+                    if (isset($fptr->area) &&  ((string) $fptr->area->attributes()->BETYPE === 'TIME')) {
                         // Check if file has valid @USE attribute.
-                        if (!empty($fileUse[(string) $fptr->attributes()->FILEID])) {
-                            $this->physicalStructureInfo[$elements[$order]]['files'][$fileUse[(string) $fptr->attributes()->FILEID]] = (string) $fptr->attributes()->FILEID;
-                        }
-                    }
-
-                    // Get track info wtih begin end extent time for later assignment with musical
-                    if ((string) $elementNode['TYPE'] === 'track') {
-                        foreach ($elementNode->children('http://www.loc.gov/METS/')->fptr as $fptr) {
-                            if (isset($fptr->area) &&  ((string) $fptr->area->attributes()->BETYPE === 'TIME')) {
-                                // Check if file has valid @USE attribute.
-                                if (!empty($fileUse[(string) $fptr->area->attributes()->FILEID])) {
-                                    $this->physicalStructureInfo[$elements[(int) $elementNode['ORDER']]]['tracks'][$fileUse[(string) $fptr->area->attributes()->FILEID]] = [
-                                        'fileid'  => (string)$fptr->area->attributes()->FILEID,
-                                        'begin'   => (string)$fptr->area->attributes()->BEGIN,
-                                        'betype'  => (string)$fptr->area->attributes()->BETYPE,
-                                        'extent'  => (string)$fptr->area->attributes()->EXTENT,
-                                        'exttype' => (string)$fptr->area->attributes()->EXTTYPE,
-                                    ];
-                                }
-                            }
+                        if (!empty($fileUse[(string) $fptr->area->attributes()->FILEID])) {
+                            $this->physicalStructureInfo[$elements[(int) $elementNode['ORDER']]]['tracks'][$fileUse[(string) $fptr->area->attributes()->FILEID]] = [
+                                'fileid'  => (string)$fptr->area->attributes()->FILEID,
+                                'begin'   => (string)$fptr->area->attributes()->BEGIN,
+                                'betype'  => (string)$fptr->area->attributes()->BETYPE,
+                                'extent'  => (string)$fptr->area->attributes()->EXTENT,
+                                'exttype' => (string)$fptr->area->attributes()->EXTTYPE,
+                            ];
                         }
                     }
                 }
-                // Sort array by keys (= @ORDER).
-                ksort($elements);
-                // Set total number of pages/tracks.
-                $this->numPages = count($elements);
-                // Merge and re-index the array to get numeric indexes.
-                array_unshift($elements, $id);
-                $this->physicalStructure = $elements;
             }
-            $this->physicalStructureLoaded = true;
-
         }
 
-        return $this->physicalStructure;
+        // Sort array by keys (= @ORDER).
+        ksort($elements);
+        // Set total number of pages/tracks.
+        $this->numPages = count($elements);
+        // Merge and re-index the array to get numeric indexes.
+        array_unshift($elements, $id);
+
+        return $elements;
     }
 
     /**
@@ -1484,7 +1569,7 @@ public function magicGetParentHref(): string
      */
     public function __sleep(): array
     {
-        // \SimpleXMLElement objects can't be serialized, thus save the XML as string for serialization
+        // SimpleXMLElement objects can't be serialized, thus save the XML as string for serialization
         $this->asXML = $this->xml->asXML();
         return ['pid', 'recordId', 'parentId', 'asXML'];
     }
diff --git a/Classes/Controller/BasketController.php b/Classes/Controller/BasketController.php
index e3e3ced84..2240cbd27 100644
--- a/Classes/Controller/BasketController.php
+++ b/Classes/Controller/BasketController.php
@@ -268,20 +268,18 @@ protected function getBasketData(): Basket
      *
      * @access protected
      *
-     * @param array $data DocumentData
+     * @param bool|null|object $data DocumentData
      *
      * @return array One basket entry
      */
-    protected function getEntry(array $data): array
+    protected function getEntry($data): array
     {
-        // TODO: Call to function is_object() with array will always evaluate to false.
-        // @phpstan-ignore-next-line
         if (is_object($data)) {
             $data = get_object_vars($data);
         }
         $id = $data['id'];
-        $startpage = $data['startpage'];
-        $endpage = $data['endpage'];
+        $startPage = $data['startpage'];
+        $endPage = $data['endpage'];
         $startX = $data['startX'];
         $startY = $data['startY'];
         $endX = $data['endX'];
@@ -290,9 +288,7 @@ protected function getEntry(array $data): array
 
         $docData = $this->getDocumentData((int) $id, $data);
 
-        $entryArray['BASKETDATA'] = $docData;
-
-        $entryKey = $id . '_' . $startpage;
+        $entryKey = $id . '_' . $startPage;
         if (!empty($startX)) {
             $entryKey .= '_' . $startX;
         }
@@ -300,10 +296,16 @@ protected function getEntry(array $data): array
             $entryKey .= '_' . $endX;
         }
 
-        $entryArray['id'] = $id;
-        $entryArray['CONTROLS'] = [
-            'startpage' => $startpage,
-            'endpage' => $endpage,
+        $entry = [
+            'BASKETDATA' => $docData,
+            'id' => $id,
+            'NUMBER' => $docData['record_id'],
+            'key' => $entryKey
+        ];
+
+        $entry['CONTROLS'] = [
+            'startpage' => $startPage,
+            'endpage' => $endPage,
             'startX' => $startX,
             'startY' => $startY,
             'endX' => $endX,
@@ -311,11 +313,8 @@ protected function getEntry(array $data): array
             'rotation' => $rotation,
         ];
 
-        $entryArray['NUMBER'] = $docData['record_id'];
-        $entryArray['key'] = $entryKey;
-
         // return one entry
-        return $entryArray;
+        return $entry;
     }
 
     /**
diff --git a/Classes/Controller/CollectionController.php b/Classes/Controller/CollectionController.php
index c44822b5c..ed1e2d44b 100644
--- a/Classes/Controller/CollectionController.php
+++ b/Classes/Controller/CollectionController.php
@@ -81,9 +81,7 @@ public function listAction(): void
             $this->logger->error('Apache Solr not available');
             return;
         }
-        // We only care about the UID and partOf in the results and want them sorted
-        $params['fields'] = 'uid,partof';
-        $params['sort'] = ['uid' => 'asc'];
+
         $collections = [];
 
         // Sort collections according to order in plugin flexform configuration
@@ -220,22 +218,29 @@ private function processCollections($collections, Solr $solr): array
 
         // Process results.
         foreach ($collections as $collection) {
-            $solr_query = '';
+            $solrQuery = '';
             if ($collection->getIndexSearch() != '') {
-                $solr_query .= '(' . $collection->getIndexSearch() . ')';
+                $solrQuery .= '(' . $collection->getIndexSearch() . ')';
             } else {
-                $solr_query .= 'collection:("' . Solr::escapeQuery($collection->getIndexName()) . '")';
+                $solrQuery .= 'collection:("' . Solr::escapeQuery($collection->getIndexName()) . '")';
             }
 
+            // We only care about the UID and partOf in the results and want them sorted
+            $params = [
+                'fields' => 'uid,partof',
+                'sort' => [
+                    'uid' => 'asc'
+                ]
+            ];
             // virtual collection might yield documents, that are not toplevel true or partof anything
             if ($collection->getIndexSearch()) {
-                $params['query'] = $solr_query;
+                $params['query'] = $solrQuery;
             } else {
-                $params['query'] = $solr_query . ' AND partof:0 AND toplevel:true';
+                $params['query'] = $solrQuery . ' AND partof:0 AND toplevel:true';
             }
             $partOfNothing = $solr->searchRaw($params);
 
-            $params['query'] = $solr_query . ' AND NOT partof:0 AND toplevel:true';
+            $params['query'] = $solrQuery . ' AND NOT partof:0 AND toplevel:true';
             $partOfSomething = $solr->searchRaw($params);
 
             $collectionInfo = [];
diff --git a/Classes/Controller/TableOfContentsController.php b/Classes/Controller/TableOfContentsController.php
index 8beaf70c3..7bbcefd43 100644
--- a/Classes/Controller/TableOfContentsController.php
+++ b/Classes/Controller/TableOfContentsController.php
@@ -131,44 +131,8 @@ private function getMenuEntry(array $entry, bool $recursive = false): array
         $entryArray['doNotLinkIt'] = 1;
         $entryArray['ITEM_STATE'] = 'NO';
 
-        // Build menu links based on the $entry['points'] array.
-        if (
-            !empty($entry['points'])
-            && MathUtility::canBeInterpretedAsInteger($entry['points'])
-        ) {
-            $entryArray['page'] = $entry['points'];
+        $this->buildMenuLinks($entryArray, $entry['id'], $entry['points'], $entry['targetUid']);
 
-            $entryArray['doNotLinkIt'] = 0;
-            if (isset($this->settings['basketButton'])) {
-                $entryArray['basketButton'] = [
-                    'logId' => $entry['id'],
-                    'startpage' => $entry['points']
-                ];
-            }
-        } elseif (
-            !empty($entry['points'])
-            && is_string($entry['points'])
-        ) {
-            $entryArray['id'] = $entry['points'];
-            $entryArray['page'] = 1;
-            $entryArray['doNotLinkIt'] = 0;
-            if (isset($this->settings['basketButton'])) {
-                $entryArray['basketButton'] = [
-                    'logId' => $entry['id'],
-                    'startpage' => $entry['points']
-                ];
-            }
-        } elseif (!empty($entry['targetUid'])) {
-            $entryArray['id'] = $entry['targetUid'];
-            $entryArray['page'] = 1;
-            $entryArray['doNotLinkIt'] = 0;
-            if (isset($this->settings['basketButton'])) {
-                $entryArray['basketButton'] = [
-                    'logId' => $entry['id'],
-                    'startpage' => $entry['targetUid']
-                ];
-            }
-        }
         // Set "ITEM_STATE" to "CUR" if this entry points to current page.
         if (in_array($entry['id'], $this->activeEntries)) {
             $entryArray['ITEM_STATE'] = 'CUR';
@@ -202,6 +166,61 @@ private function getMenuEntry(array $entry, bool $recursive = false): array
         return $entryArray;
     }
 
+    /**
+     * Build menu links based on the $entry['points'] array.
+     *
+     * @access private
+     *
+     * @param array &$entryArray passed by reference
+     * @param mixed $id
+     * @param mixed $points
+     * @param mixed $targetUid
+     *
+     * @return void
+     */
+    private function buildMenuLinks(array &$entryArray, $id, $points, $targetUid): void
+    {
+        if (
+            !empty($points)
+            && MathUtility::canBeInterpretedAsInteger($points)
+        ) {
+            $entryArray['page'] = $points;
+            $entryArray['doNotLinkIt'] = 0;
+            $this->setBasket($entryArray, $id, $points);
+        } elseif (
+            !empty($points)
+            && is_string($points)
+        ) {
+            $entryArray['id'] = $points;
+            $entryArray['page'] = 1;
+            $entryArray['doNotLinkIt'] = 0;
+            $this->setBasket($entryArray, $id, $points);
+        } elseif (!empty($targetUid)) {
+            $entryArray['id'] = $targetUid;
+            $entryArray['page'] = 1;
+            $entryArray['doNotLinkIt'] = 0;
+            $this->setBasket($entryArray, $id, $targetUid);
+        }
+    }
+
+    /**
+     * Set basket if basket is included in settings.
+     *
+     * @param array $entryArray passed by reference
+     * @param mixed $id
+     * @param mixed $startPage
+     * @return void
+     */
+    private function setBasket(array &$entryArray, $id, $startPage): void
+    {
+        if (isset($this->settings['basketButton'])) {
+            $entryArray['basketButton'] = [
+                'logId' => $id,
+                'startpage' => $startPage
+            ];
+        }
+    }
+
     /**
      * If $entry references an external METS file (as mptr),
      * try to resolve its database UID and return an updated $entry.
@@ -241,18 +260,25 @@ private function resolveMenuEntry(array $entry): array
      */
     private function getAllLogicalUnits(): void
     {
+        $page = $this->requestData['page'];
+        $physicalStructure = $this->document->getCurrentDocument()->physicalStructure;
         if (
-            !empty($this->requestData['page'])
-            && !empty($this->document->getCurrentDocument()->physicalStructure)
+            !empty($page)
+            && !empty($physicalStructure)
         ) {
-            $this->activeEntries = array_merge((array) $this->document->getCurrentDocument()->smLinks['p2l'][$this->document->getCurrentDocument()->physicalStructure[0]],
-                (array) $this->document->getCurrentDocument()->smLinks['p2l'][$this->document->getCurrentDocument()->physicalStructure[$this->requestData['page']]]);
+            $structureMapLinks = $this->document->getCurrentDocument()->smLinks;
+            $this->activeEntries = array_merge(
+                (array) $structureMapLinks['p2l'][$physicalStructure[0]],
+                (array) $structureMapLinks['p2l'][$physicalStructure[$page]]
+            );
             if (
                 !empty($this->requestData['double'])
-                && $this->requestData['page'] < $this->document->getCurrentDocument()->numPages
+                && $page < $this->document->getCurrentDocument()->numPages
             ) {
-                $this->activeEntries = array_merge($this->activeEntries,
-                    (array) $this->document->getCurrentDocument()->smLinks['p2l'][$this->document->getCurrentDocument()->physicalStructure[$this->requestData['page'] + 1]]);
+                $this->activeEntries = array_merge(
+                    $this->activeEntries,
+                    (array) $structureMapLinks['p2l'][$physicalStructure[$page + 1]]
+                );
             }
         }
     }
@@ -302,7 +328,10 @@ private function isMultiElement(string $type): bool
      */
     private function setTitle(array $entry): string
     {
-        if (empty($entry['label']) && empty($entry['orderlabel'])) {
+        $label = $entry['label'];
+        $orderLabel = $entry['orderlabel'];
+
+        if (empty($label) && empty($orderLabel)) {
             foreach ($this->settings['titleReplacements'] as $titleReplacement) {
                 if ($entry['type'] == $titleReplacement['type']) {
                     $fields = explode(",", $titleReplacement['fields']);
@@ -314,12 +343,11 @@ private function setTitle(array $entry): string
                             $title .= $entry[$field] . ' ';
                         }
                     }
-        
                     return trim($title);
                 }
             }
         }
-        return $entry['label'] ?: $entry['orderlabel'];
+        return $label ?: $orderLabel;
     }
 
     /**
@@ -352,11 +380,14 @@ private function sortMenu(array &$menu): void
      */
     private function sortSubMenu(array &$menu): void
     {
-        usort($menu[0]['_SUB_MENU'], function ($firstElement, $secondElement) {
-            if (!empty($firstElement['orderlabel'])) {
-                return $firstElement['orderlabel'] <=> $secondElement['orderlabel'];
+        usort(
+            $menu[0]['_SUB_MENU'],
+            function ($firstElement, $secondElement) {
+                if (!empty($firstElement['orderlabel'])) {
+                    return $firstElement['orderlabel'] <=> $secondElement['orderlabel'];
+                }
+                return $firstElement['year'] <=> $secondElement['year'];
             }
-            return $firstElement['year'] <=> $secondElement['year'];
-        });
+        );
     }
 }
diff --git a/Classes/Hooks/DataHandler.php b/Classes/Hooks/DataHandler.php
index cf2461210..6304efcbd 100644
--- a/Classes/Hooks/DataHandler.php
+++ b/Classes/Hooks/DataHandler.php
@@ -157,7 +157,8 @@ public function processDatamap_postProcessFieldArray(string $status, string $tab
                             ->setMaxResults(1)
                             ->execute();
 
-                        if ($resArray = $result->fetchAssociative()) {
+                        $resArray = $result->fetchAssociative();
+                        if (is_array($resArray)) {
                             // Reset storing to current.
                             $fieldArray['index_stored'] = $resArray['is_listed'];
                         }
@@ -244,27 +245,12 @@ public function processDatamap_afterDatabaseOperations(string $status, string $t
                             ->setMaxResults(1)
                             ->execute();
 
-                        if ($resArray = $result->fetchAssociative()) {
+                        $resArray = $result->fetchAssociative();
+                        if (is_array($resArray)) {
                             if ($resArray['hidden']) {
-                                // Establish Solr connection.
-                                $solr = Solr::getInstance($resArray['core']);
-                                if ($solr->ready) {
-                                    // Delete Solr document.
-                                    $updateQuery = $solr->service->createUpdate();
-                                    $updateQuery->addDeleteQuery('uid:' . (int) $id);
-                                    $updateQuery->addCommit();
-                                    $solr->service->update($updateQuery);
-                                }
+                                $this->deleteDocument($resArray['core'], $id);
                             } else {
-                                // Reindex document.
-                                $document = $this->getDocumentRepository()->findByUid((int) $id);
-                                $doc = AbstractDocument::getInstance($document->getLocation(), ['storagePid' => $document->getPid()], true);
-                                if ($document !== null && $doc !== null) {
-                                    $document->setCurrentDocument($doc);
-                                    Indexer::add($document, $this->getDocumentRepository());
-                                } else {
-                                    $this->logger->error('Failed to re-index document with UID ' . (string) $id);
-                                }
+                                $this->reindexDocument($id);
                             }
                         }
                     }
@@ -321,32 +307,17 @@ public function processCmdmap_postProcess(string $command, string $table, $id):
                 ->setMaxResults(1)
                 ->execute();
 
-            if ($resArray = $result->fetchAssociative()) {
+            $resArray = $result->fetchAssociative();
+            if (is_array($resArray)) {
                 switch ($command) {
                     case 'move':
                     case 'delete':
-                        // Establish Solr connection.
-                        $solr = Solr::getInstance($resArray['core']);
-                        if ($solr->ready) {
-                            // Delete Solr document.
-                            $updateQuery = $solr->service->createUpdate();
-                            $updateQuery->addDeleteQuery('uid:' . (int) $id);
-                            $updateQuery->addCommit();
-                            $solr->service->update($updateQuery);
-                            if ($command == 'delete') {
-                                break;
-                            }
+                        $this->deleteDocument($resArray['core'], $id);
+                        if ($command == 'delete') {
+                            break;
                         }
                     case 'undelete':
-                        // Reindex document.
-                        $document = $this->getDocumentRepository()->findByUid((int) $id);
-                        $doc = AbstractDocument::getInstance($document->getLocation(), ['storagePid' => $document->getPid()], true);
-                        if ($document !== null && $doc !== null) {
-                            $document->setCurrentDocument($doc);
-                            Indexer::add($document, $this->getDocumentRepository());
-                        } else {
-                            $this->logger->error('Failed to re-index document with UID ' . (string) $id);
-                        }
+                        $this->reindexDocument($id);
                         break;
                 }
             }
@@ -355,48 +326,106 @@ public function processCmdmap_postProcess(string $command, string $table, $id):
             $command === 'delete'
             && $table == 'tx_dlf_solrcores'
         ) {
-            // Is core deletion allowed in extension configuration?
-            $extConf = GeneralUtility::makeInstance(ExtensionConfiguration::class)->get('dlf', 'solr');
-            if (!empty($extConf['allowCoreDelete'])) {
-                // Delete core from Apache Solr as well.
-                $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
-                    ->getQueryBuilderForTable('tx_dlf_solrcores');
-                // Record in "tx_dlf_solrcores" is already deleted at this point.
-                $queryBuilder
-                    ->getRestrictions()
-                    ->removeByType(DeletedRestriction::class);
+            $this->deleteSolrCore($id);
+        }
+    }
 
-                $result = $queryBuilder
-                    ->select(
-                        'tx_dlf_solrcores.index_name AS core'
-                    )
-                    ->from('tx_dlf_solrcores')
-                    ->where($queryBuilder->expr()->eq('tx_dlf_solrcores.uid', (int) $id))
-                    ->setMaxResults(1)
-                    ->execute();
+    /**
+     * Delete document from index.
+     *
+     * @access private
+     *
+     * @param mixed $core
+     * @param int|string $id
+     *
+     * @return void
+     */
+    private function deleteDocument($core, $id): void
+    {
+        // Establish Solr connection.
+        $solr = Solr::getInstance($core);
+        if ($solr->ready) {
+            // Delete Solr document.
+            $updateQuery = $solr->service->createUpdate();
+            $updateQuery->addDeleteQuery('uid:' . (int) $id);
+            $updateQuery->addCommit();
+            $solr->service->update($updateQuery);
+        }
+    }
 
-                if ($resArray = $result->fetchAssociative()) {
-                    // Establish Solr connection.
-                    $solr = Solr::getInstance();
-                    if ($solr->ready) {
-                        // Delete Solr core.
-                        $query = $solr->service->createCoreAdmin();
-                        $action = $query->createUnload();
-                        $action->setCore($resArray['core']);
-                        $action->setDeleteDataDir(true);
-                        $action->setDeleteIndex(true);
-                        $action->setDeleteInstanceDir(true);
-                        $query->setAction($action);
-                        try {
-                            $response = $solr->service->coreAdmin($query);
-                            if ($response->getWasSuccessful()) {
-                                return;
-                            }
-                        } catch (\Exception $e) {
-                            // Nothing to do here.
+    /**
+     * Reindex document.
+     *
+     * @access private
+     *
+     * @param int|string $id
+     *
+     * @return void
+     */
+    private function reindexDocument($id):void
+    {
+        $document = $this->getDocumentRepository()->findByUid((int) $id);
+        $doc = AbstractDocument::getInstance($document->getLocation(), ['storagePid' => $document->getPid()], true);
+        if ($document !== null && $doc !== null) {
+            $document->setCurrentDocument($doc);
+            Indexer::add($document, $this->getDocumentRepository());
+        } else {
+            $this->logger->error('Failed to re-index document with UID ' . (string) $id);
+        }
+    }
+
+    /**
+     * Delete SOLR core if deletion is allowed.
+     *
+     * @access private
+     *
+     * @param int|string $id
+     *
+     * @return void
+     */
+    private function deleteSolrCore($id): void
+    {
+        // Is core deletion allowed in extension configuration?
+        $extConf = GeneralUtility::makeInstance(ExtensionConfiguration::class)->get('dlf', 'solr');
+        if (!empty($extConf['allowCoreDelete'])) {
+            // Delete core from Apache Solr as well.
+            $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
+                ->getQueryBuilderForTable('tx_dlf_solrcores');
+            // Record in "tx_dlf_solrcores" is already deleted at this point.
+            $queryBuilder
+                ->getRestrictions()
+                ->removeByType(DeletedRestriction::class);
+
+            $result = $queryBuilder
+                ->select(
+                    'tx_dlf_solrcores.index_name AS core'
+                )
+                ->from('tx_dlf_solrcores')
+                ->where($queryBuilder->expr()->eq('tx_dlf_solrcores.uid', (int) $id))
+                ->setMaxResults(1)
+                ->execute();
+
+            $resArray = $result->fetchAssociative();
+            if (is_array($resArray)) {
+                // Establish Solr connection.
+                $solr = Solr::getInstance();
+                if ($solr->ready) {
+                    // Delete Solr core.
+                    $query = $solr->service->createCoreAdmin();
+                    $action = $query->createUnload();
+                    $action->setCore($resArray['core']);
+                    $action->setDeleteDataDir(true);
+                    $action->setDeleteIndex(true);
+                    $action->setDeleteInstanceDir(true);
+                    $query->setAction($action);
+                    try {
+                        $response = $solr->service->coreAdmin($query);
+                        if ($response->getWasSuccessful() == false) {
+                            $this->logger->warning('Core ' . $resArray['core'] . ' could not be deleted from Apache Solr');
                         }
+                    } catch (\Exception $e) {
+                        $this->logger->warning($e->getMessage());
                     }
-                    $this->logger->warning('Core ' . $resArray['core'] . ' could not be deleted from Apache Solr');
                 }
             }
         }
diff --git a/Classes/Hooks/ItemsProcFunc.php b/Classes/Hooks/ItemsProcFunc.php
index c3c4277e2..f4f82c783 100644
--- a/Classes/Hooks/ItemsProcFunc.php
+++ b/Classes/Hooks/ItemsProcFunc.php
@@ -16,6 +16,7 @@
 use Psr\Log\LoggerAwareInterface;
 use Psr\Log\LoggerAwareTrait;
 use TYPO3\CMS\Backend\Utility\BackendUtility;
+use TYPO3\CMS\Core\Configuration\ConfigurationManager;
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\TypoScript\TemplateService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
@@ -50,7 +51,9 @@ class ItemsProcFunc implements LoggerAwareInterface
      */
     public function toolList(array &$params): void
     {
-        foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['dlf/Classes/Plugin/Toolbox.php']['tools'] as $class => $label) {
+        $configurationManager = GeneralUtility::makeInstance(ConfigurationManager::class);
+        $options = $configurationManager->getLocalConfigurationValueByPath('SC_OPTIONS');
+        foreach ($options['dlf/Classes/Plugin/Toolbox.php']['tools'] as $class => $label) {
             $params['items'][] = [Helper::getLanguageService()->sL($label), $class];
         }
     }
@@ -70,9 +73,9 @@ public function getTyposcriptConfigFromPluginSiteRoot(array $params): void
         $pid = $params['flexParentDatabaseRow']['pid'];
         $rootLine = BackendUtility::BEgetRootLine($pid);
         $siteRootRow = [];
-        foreach ($rootLine as $_row) {
-            if ($_row['is_siteroot'] == '1') {
-                $siteRootRow = $_row;
+        foreach ($rootLine as $row) {
+            if ($row['is_siteroot'] == '1') {
+                $siteRootRow = $row;
                 break;
             }
         }
@@ -152,7 +155,7 @@ protected function generateList(array &$params, string $fields, string $table, s
             ->select(...explode(',', $fields))
             ->from($table)
             ->where(
-                $queryBuilder->expr()->eq($table . '.pid', intval($this->storagePid)),
+                $queryBuilder->expr()->eq($table . '.pid', $this->storagePid),
                 $queryBuilder->expr()->in($table . '.sys_language_uid', [-1, 0]),
                 $andWhere
             )
diff --git a/Classes/Hooks/KitodoProductionHacks.php b/Classes/Hooks/KitodoProductionHacks.php
index e0b247e01..526cdda20 100644
--- a/Classes/Hooks/KitodoProductionHacks.php
+++ b/Classes/Hooks/KitodoProductionHacks.php
@@ -39,12 +39,16 @@ public function postProcessRecordId(\SimpleXMLElement &$xml, &$recordId): void
         if (!$recordId) {
             $xml->registerXPathNamespace('mods', 'http://www.loc.gov/mods/v3');
             // Get all logical structure nodes with metadata, but without associated METS-Pointers.
-            if (($divs = $xml->xpath('//mets:structMap[@TYPE="LOGICAL"]//mets:div[@DMDID and not(./mets:mptr)]'))) {
+            $divs = $xml->xpath('//mets:structMap[@TYPE="LOGICAL"]//mets:div[@DMDID and not(./mets:mptr)]');
+            if (is_array($divs)) {
                 $smLinks = $xml->xpath('//mets:structLink/mets:smLink');
                 if (!empty($smLinks)) {
+                    $links = [];
+
                     foreach ($smLinks as $smLink) {
                         $links[(string) $smLink->attributes('http://www.w3.org/1999/xlink')->from][] = (string) $smLink->attributes('http://www.w3.org/1999/xlink')->to;
                     }
+
                     foreach ($divs as $div) {
                         if (!empty($links[(string) $div['ID']])) {
                             $id = (string) $div['DMDID'];
diff --git a/Tests/Functional/FunctionalTestCase.php b/Tests/Functional/FunctionalTestCase.php
index 7c3b021bb..c5631ed41 100644
--- a/Tests/Functional/FunctionalTestCase.php
+++ b/Tests/Functional/FunctionalTestCase.php
@@ -44,6 +44,9 @@ class FunctionalTestCase extends \TYPO3\TestingFramework\Core\Functional\Functio
             ],
             'displayErrors' => '1'
         ],
+        'SC_OPTIONS' => [
+            'dlf/Classes/Plugin/Toolbox.php' => []
+        ],
         'EXTENSIONS' => [
             'dlf' => [], // = $this->getDlfConfiguration(), set in constructor
         ],