Refactor TLVTree to not have a View attribute

Reasoning: The mental model was a bit confusing, since
the Model\View reads the YAML and has a Tree attribute, while
this Tree had the same View as attribute.

But we only need some attributes from the View in the Tree,
might even be possible to use Model\View instead of Tree in some cases
and then use view->getTree().

application/views/helpers/Tiles.php

@@ -35,7 +35,7 @@ public function tiles(TLVTreeNode $node, $levels = 2, $classes = array())
             $title . $badges,
             'toplevelview/show/tree',
             array(
-                'name' => $node->getRoot()->getView()->getName(),
+                'name' => $node->getRoot()->getViewName(),
                 'id'   => $node->getFullId()
             ),
             array(

application/views/helpers/Tree.php

@@ -71,7 +71,7 @@ public function tree(TLVTreeNode $node, $classes = array(), $level = 0)
             $url = Url::fromPath(
                 'toplevelview/show/tree',
                 array(
-                    'name' => $node->getRoot()->getView()->getName(),
+                    'name' => $node->getRoot()->getViewName(),
                     'id'   => $node->getFullId()
                 )
             );

library/Toplevelview/Model/View.php

@@ -82,7 +82,8 @@ public function getTree(): TLVTree
         if ($this->tree === null) {
             $this->ensureParsed();
             $this->tree = $tree = TLVTree::fromArray($this->raw);
-            $tree->setView($this);
+            $tree->setViewName($this->getName());
+            $tree->setViewChecksum($this->getTextChecksum());
         }
         return $this->tree;
     }

library/Toplevelview/Tree/TLVTree.php

@@ -38,10 +38,9 @@ class TLVTree extends TLVTreeNode
 
     protected $cacheLifetime = 60;
 
-    /**
-     * @var View
-     */
-    protected $view;
+    protected $viewName;
+
+    protected $viewChecksum;
 
     /**
      * Return a child by its ID
@@ -70,22 +69,25 @@ public function getById($id)
         return $currentNode;
     }
 
-    /**
-     * @return View
-     */
-    public function getView()
+    public function getViewName(): string
     {
-        return $this->view;
+        return $this->viewName;
     }
 
-    /**
-     * @param View $view
-     *
-     * @return $this
-     */
-    public function setView(View $view)
+    public function setViewName(string $name)
+    {
+        $this->viewName = $name;
+        return $this;
+    }
+
+    public function getViewChecksum(): string
+    {
+        return $this->viewChecksum;
+    }
+
+    public function setViewChecksum(string $checksum)
     {
-        $this->view = $view;
+        $this->viewChecksum = $checksum;
         return $this;
     }
 
@@ -111,12 +113,9 @@ public function registerObject($type, $name, $class)
 
     protected function getCacheName()
     {
-        $view = $this->getView();
-        return sprintf(
-            '%s-%s.json',
-            $view->getName(),
-            $view->getTextChecksum()
-        );
+        $n = $this->getViewName();
+        $c = $this->getViewChecksum();
+        return sprintf('%s-%s.json', $n, $c);
     }
 
     protected function loadCache()

test/php/library/Toplevelview/ViewConfigTest.php

@@ -5,6 +5,7 @@
 use Icinga\Module\Toplevelview\ViewConfig;
 
 use Icinga\Exception\NotReadableError;
+use Icinga\Exception\NotFoundError;
 use PHPUnit\Framework\TestCase;
 
 final class ViewConfigTest extends TestCase
@@ -31,4 +32,15 @@ public function testViewConfigWithNoError()
         $this->assertSame(null, $clone->getName());
         $this->assertFalse($clone->hasBeenLoaded());
     }
+
+    public function testViewConfigWithTree()
+    {
+        $this->expectException(NotFoundError::class);
+
+        $c = new ViewConfig('test/testdata');
+        $view = $c->loadByName('example');
+
+        $t = $view->getTree();
+        $t->getById('0-1-2');
+    }
 }