my changes

app/Library/Xml/XmlModel.php

@@ -0,0 +1,180 @@
+<?php
+
+/**
+ * Footer
+ *
+ * Main footer file for the theme.
+ *
+ * @category   Components
+ * @package    ResearchRepository
+ * @subpackage Publish
+ * @author     Your Name <yourname@example.com>
+ * @license    https://www.gnu.org/licenses/gpl-3.0.txt GNU/GPLv3
+ * @link       https://gisgba.geologie.ac.at
+ * @since      1.0.0
+ */
+namespace App\Library\Xml;
+
+use App\XmlCache;
+use Illuminate\Support\Facades\Log;
+
+class XmlModel
+{
+    /**
+     * Holds current configuration.
+     * @var Conf
+     */
+    private $_config = null;
+
+    /**
+     * Holds current xml strategy object.
+     * @var Strategy
+     */
+    private $_strategy = null;
+
+    /**
+     * TODO
+     * @var XmlCache
+     */
+    private $_cache = null;
+
+
+    /**
+     * Do some initial stuff like setting of a XML version and an empty
+     * configuration.
+     */
+    public function __construct()
+    {
+        $this->_strategy = new Strategy();// Opus_Model_Xml_Version1;
+        $this->_config = new Conf();
+        $this->_strategy->setup($this->_config);
+    }
+
+    /**
+     * Set a new XML version with current configuration up.
+     *
+     * @param Strategy $strategy Version of Xml to process
+     *
+     * @return XmlModel fluent interface.
+     */
+    public function setStrategy(Strategy $strategy)
+    {
+        $this->_strategy = $strategy;
+        $this->_strategy->setup($this->_config);
+        return $this;
+    }
+
+    /**
+     * Set a new XML version with current configuration up.
+     *
+     * @param XmlCache $cache cach table
+     *
+     * @return XmlModel fluent interface.
+     */
+    public function setXmlCache(XmlCache $cache)
+    {
+        $this->_cache = $cache;
+        return $this;
+    }
+
+    /**
+     * Return cache table.
+     *
+     * @return XmlCache
+     */
+    public function getXmlCache()
+    {
+        return $this->_cache;
+    }
+
+    /**
+     * Set the Model for XML generation.
+     *
+     * @param \App\Dataset $model Model to serialize.
+     *
+     * @return XmlModel Fluent interface.
+     */
+    public function setModel($model)
+    {
+        $this->_config->model = $model;
+        return $this;
+    }
+
+    /**
+     * Define that empty fields (value===null) shall be excluded.
+     *
+     * @return XmlModel Fluent interface
+     */
+    public function excludeEmptyFields()
+    {
+        $this->_config->excludeEmpty = true;
+        return $this;
+    }
+
+    /**
+     * If a model has been set this method generates and returnes
+     * DOM representation of it.
+     *
+     * @return \DOMDocument DOM representation of the current Model.
+     */
+    public function getDomDocument()
+    {
+        $dataset = $this->_config->model;
+
+        $domDocument = $this->getDomDocumentFromXmlCache();
+        if (!is_null($domDocument)) {
+            return $domDocument;
+        }
+
+        //create xml:
+        $domDocument = $this->_strategy->getDomDocument();
+        //if caching is not desired, return domDocument
+        if (is_null($this->_cache)) {
+            return $domDocument;
+        } else {
+            //create cache relation
+            $this->_cache->fill(array(
+                'document_id' => $dataset->id,
+                'xml_version' => (int)$this->_strategy->getVersion(),
+                'server_date_modified' => $dataset->server_date_modified,
+                'xml_data' => $domDocument->saveXML()
+            ));
+            $this->_cache->save();
+
+            Log::debug(__METHOD__ . ' cache refreshed for ' . get_class($dataset) . '#' . $dataset->id);
+            return $domDocument;
+        }
+    }
+
+    /**
+     * This method tries to load the current model from the xml cache.  Returns
+     * null in case of an error/cache miss/cache disabled.  Returns DOMDocument
+     * otherwise.
+     *
+     * @return \DOMDocument DOM representation of the current Model.
+     */
+    private function getDomDocumentFromXmlCache()
+    {
+        $dataset = $this->_config->model;
+        if (null === $this->_cache) {
+            //$logger->debug(__METHOD__ . ' skipping cache for ' . get_class($model));
+            Log::debug(__METHOD__ . ' skipping cache for ' . get_class($dataset));
+            return null;
+        }
+        //$cached = $this->_cache->hasValidEntry(
+        //    $dataset->id,
+        //    (int) $this->_strategy->getVersion(),
+        //    $dataset->server_date_modified
+        //);
+
+        //$cached = false;
+        $cache = XmlCache::where('document_id', $dataset->id)
+            ->first();// model or null
+        if (!$cache) {
+            Log::debug(__METHOD__ . ' cache miss for ' . get_class($dataset) . '#' . $dataset->id);
+            return null;
+        } else {
+            return $cache->getDomDocument();
+        }
+    }
+}