Add a layer to transform the models into renderable content

Author: BeneRoch

src/Charcoal/Sitemap/Service/Builder.php

@@ -51,6 +51,11 @@ class Builder
      */
     private $collectionLoader;
 
+    /**
+     * @var SitemapPresenter
+     */
+    private $sitemapPresenter;
+
     /**
      * Create the Sitemap Builder.
      *
@@ -80,6 +85,7 @@ public function __construct(array $data)
         $this->setModelFactory($data['model/factory']);
         $this->setCollectionLoader($data['model/collection/loader']);
         $this->setTranslator($data['translator']);
+        $this->setSitemapPresenter($data['sitemap/presenter']);
 
         return $this;
     }
@@ -114,12 +120,13 @@ protected function defaultOptions()
             'l10n'                => true,
             'check_active_routes' => true,
             'relative_urls'       => true,
+            'transformer'         => null,
             'objects'             => [
                 'label'    => '{{title}}',
                 'url'      => '{{url}}',
                 'children' => [],
                 'data'     => [],
-            ],
+            ]
         ];
     }
 
@@ -179,6 +186,10 @@ public function build($ident = 'default')
                 $options['relative_urls'] = $defaults['relative_urls'];
             }
 
+            if (!isset($options['transformer'])) {
+                $options['transformer'] = $defaults['transformer'];
+            }
+
             $out[] = $this->buildObject($class, $options);
         }
 
@@ -212,7 +223,7 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
         if (isset($options['filters'])) {
             $filters = $options['filters'];
             if ($parent) {
-                $filters = $this->renderData($parent, $filters);
+                $filters = $this->renderData($parent, $filters, $options['transformer']);
             }
             $loader->addFilters($filters);
         }
@@ -221,7 +232,7 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
         if (isset($options['orders'])) {
             $orders = $options['orders'];
             if ($parent) {
-                $orders = $this->renderData($parent, $orders);
+                $orders = $this->renderData($parent, $orders, $options['transformer']);
             }
             $loader->addOrders($orders);
         }
@@ -239,6 +250,7 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
         $defaultLocale     = $options['locale'];
         $checkActiveRoutes = $options['check_active_routes'];
         $relativeUrls      = $options['relative_urls'];
+        $transformer       = $options['transformer'];
 
         // Locales
         $availableLocales = $l10n
@@ -264,38 +276,40 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
                     continue;
                 }
 
+                $presentedParent = $this->sitemapPresenter()->transform($object, $transformer);
+
                 // Hierarchical (children, when defined)
                 $cs = [];
                 if (!empty($children)) {
                     foreach ($children as $cname => $opts) {
                         $opts = array_merge($this->defaultOptions(), $opts);
-                        $cs[] = $this->buildObject($cname, $opts, $object, $level);
+                        $cs[] = $this->buildObject($cname, $opts, $presentedParent, $level);
                     }
                 }
 
                 $url = $relativeUrls
-                    ? trim($this->renderData($object, $options['url']))
-                    : $this->withBaseUrl(trim($this->renderData($object, $options['url'])));
+                    ? trim($this->renderData($object, $options['url'], $transformer))
+                    : $this->withBaseUrl(trim($this->renderData($object, $options['url'], $transformer)));
                 $tmp = [
-                    'label'    => trim($this->renderData($object, $options['label'])),
+                    'label'    => trim($this->renderData($object, $options['label'], $transformer)),
                     'url'      => $url,
                     'children' => $cs,
-                    'data'     => $this->renderData($object, $options['data']),
+                    'data'     => $this->renderData($object, $options['data'], $transformer),
                     'level'    => $level,
                     'lang'     => $locale,
                 ];
 
                 // If you need a priority, fix your own rules
                 $priority = '';
                 if (isset($options['priority']) && $options['priority']) {
-                    $priority = $this->renderData($object, (string)$options['priority']);
+                    $priority = $this->renderData($object, (string)$options['priority'], $transformer);
                 }
                 $tmp['priority'] = $priority;
 
                 // If you need a date of last modification, fix your own rules
                 $last = '';
                 if (isset($options['last_modified']) && $options['last_modified']) {
-                    $last = $this->renderData($object, $options['last_modified']);
+                    $last = $this->renderData($object, $options['last_modified'], $transformer);
                 }
                 $tmp['last_modified'] = $last;
 
@@ -310,8 +324,8 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
                     }
 
                     $url = $relativeUrls
-                        ? trim($this->renderData($object, $options['url']))
-                        : $this->withBaseUrl(trim($this->renderData($object, $options['url'])));
+                        ? trim($this->renderData($object, $options['url'], $transformer))
+                        : $this->withBaseUrl(trim($this->renderData($object, $options['url'], $transformer)));
 
                     $alternates[] = [
                         'url'  => $url,
@@ -336,10 +350,11 @@ protected function buildObject($class, $options, ViewableInterface $parent = nul
      * @param  mixed             $data Pretty much anything to be rendered
      * @return mixed Rendered data.
      */
-    protected function renderData(ViewableInterface $obj, $data)
+    protected function renderData(ViewableInterface $obj, $data, $transformer = null)
     {
         if (is_scalar($data)) {
-            return $obj->view()->render($data, $obj);
+            $presentedObject = $this->sitemapPresenter()->transform($obj, $transformer);
+            return $obj->view()->render($data, $presentedObject);
         }
 
         if (is_array($data)) {
@@ -429,6 +444,24 @@ protected function setCollectionLoader(CollectionLoader $loader)
         $this->collectionLoader = $loader;
     }
 
+    /**
+     * @return SitemapPresenter
+     */
+    public function sitemapPresenter()
+    {
+        return $this->sitemapPresenter;
+    }
+
+    /**
+     * @param SitemapPresenter $sitemapPresenter
+     * @return Builder
+     */
+    public function setSitemapPresenter(SitemapPresenter $sitemapPresenter)
+    {
+        $this->sitemapPresenter = $sitemapPresenter;
+        return $this;
+    }
+
     /**
      * Get the website's base URL.
      *

src/Charcoal/Sitemap/Service/SitemapPresenter.php

@@ -0,0 +1,205 @@
+<?php
+
+namespace Charcoal\Sitemap\Service;
+
+use ArrayAccess;
+use Charcoal\Cache\Facade\CachePoolFacade;
+use Charcoal\Factory\FactoryInterface;
+use InvalidArgumentException;
+use Traversable;
+
+/**
+ * Presenter provides a presentation and transformation layer for a "model".
+ *
+ * It transforms (serializes) any data model (objects or array) into a presentation array, according to a
+ * **transformer**.
+ *
+ * A **transformer** defines the morph rules
+ *
+ * - A simple array or Traversable object, contain
+ */
+class SitemapPresenter
+{
+    /**
+     * @var FactoryInterface $transformer
+     */
+    private $transformerFactory;
+
+    /**
+     * @var string $getterPattern
+     */
+    private $getterPattern;
+
+    /**
+     * @var CachePoolFacade
+     */
+    protected $cacheFacade;
+
+    /**
+     * @param array|Traversable|callable $transformer   The data-view transformation array (or Traversable) object.
+     * @param string                     $getterPattern The string pattern to match string with. Must have a single
+     *                                                  catch-block.
+     */
+    public function __construct($transformerFactory, $cacheFacade, $getterPattern = '~{{(\w*?)}}~')
+    {
+        $this->setCacheFacade($cacheFacade);
+        $this->setTransformerFactory($transformerFactory);
+        $this->getterPattern = $getterPattern;
+    }
+
+    /**
+     * @param  mixed       $obj         The model or value object.
+     * @param  string|null $transformer The specific transformer to use.
+     * @return array Normalized data, suitable as presentation (view) layer
+     */
+    public function transform($obj, $transformer = null)
+    {
+        if (!is_object($transformer)) {
+            $transformer = $this->getTransformerFactory()->create($transformer ?? $obj->objType());
+        }
+
+        $key = sprintf(
+            '%s_%s_%s',
+            get_class($transformer),
+            $obj->objType(),
+            $obj->id()
+        );
+
+        $that = $this;
+
+        return $this->getCacheFacade()->get($key,
+            function () use ($obj, $transformer, $that) {
+                return $that->transmogrify($obj, $transformer($obj));
+            });
+    }
+
+    /**
+     * Transmogrify an object into an other structure.
+     *
+     * @param mixed $obj Source object.
+     * @param mixed $val Modifier.
+     * @throws InvalidArgumentException If the modifier is not callable, traversable (array) or string.
+     * @return mixed The transformed data (type depends on modifier).
+     */
+    private function transmogrify($obj, $val)
+    {
+        // Callbacks (lambda or callable) are supported. They must accept the source object as argument.
+        if (!is_string($val) && is_callable($val)) {
+            return $val($obj);
+        }
+
+        // Arrays or traversables are handled recursively.
+        // This also converts / casts any Traversable into a simple array.
+        if (is_array($val) || $val instanceof Traversable) {
+            $data = [];
+            foreach ($val as $k => $v) {
+                if (!is_string($k)) {
+                    if (is_string($v)) {
+                        $data[$v] = $this->objectGet($obj, $v);
+                    } else {
+                        $data[] = $v;
+                    }
+                } else {
+                    $data[$k] = $this->transmogrify($obj, $v);
+                }
+            }
+            return $data;
+        }
+
+        // Strings are handled by rendering {{property}}  with dynamic object getter pattern.
+        if (is_string($val)) {
+            return preg_replace_callback($this->getterPattern, function (array $matches) use ($obj) {
+                return $this->objectGet($obj, $matches[1]);
+            }, $val);
+        }
+
+        if (is_numeric($val)) {
+            return $val;
+        }
+
+        if (is_bool($val)) {
+            return !!$val;
+        }
+
+        if ($val === null) {
+            return null;
+        }
+
+        // Any other
+        throw new InvalidArgumentException(
+            sprintf(
+                'Presenter\'s transmogrify val needs to be callable, traversable (array) or a string. "%s" given.',
+                gettype($val)
+            )
+        );
+    }
+
+    /**
+     * General-purpose dynamic object "getter".
+     *
+     * This method tries to fetch a "property" from any type of object (or array),
+     * trying to figure out the best possible way:
+     *
+     * - Method call (`$obj->property()`)
+     * - Public property get (`$obj->property`)
+     * - Array access, if available (`$obj[property]`)
+     * - Returns the property unchanged, otherwise
+     *
+     * @param mixed  $obj          The model (object or array) to retrieve the property's value from.
+     * @param string $propertyName The property name (key) to retrieve from model.
+     * @throws InvalidArgumentException If the property name is not a string.
+     * @return mixed The object property, if available. The property name, unchanged, if it's not available.
+     */
+    private function objectGet($obj, $propertyName)
+    {
+        if (is_callable([$obj, $propertyName])) {
+            return $obj->{$propertyName}();
+        }
+
+        if (isset($obj->{$propertyName})) {
+            return $obj->{$propertyName};
+        }
+
+        if (is_string($propertyName) && (is_array($obj) || $obj instanceof ArrayAccess) && (isset($obj[$propertyName]))) {
+            return $obj[$propertyName];
+        }
+
+        return null;
+    }
+
+    /**
+     * @return FactoryInterface
+     */
+    protected function getTransformerFactory()
+    {
+        return $this->transformerFactory;
+    }
+
+    /**
+     * @param FactoryInterface $transformerFactory
+     * @return Presenter
+     */
+    public function setTransformerFactory(FactoryInterface $transformerFactory)
+    {
+        $this->transformerFactory = $transformerFactory;
+        return $this;
+    }
+
+    /**
+     * @return mixed
+     */
+    protected function getCacheFacade()
+    {
+        return $this->cacheFacade;
+    }
+
+    /**
+     * @param mixed $cacheFacade
+     * @return Presenter
+     */
+    protected function setCacheFacade($cacheFacade)
+    {
+        $this->cacheFacade = $cacheFacade;
+        return $this;
+    }
+}