Fixed missing root using layout viewhelper

Author: fduarte42

src/ZendViewRenderer.php

@@ -125,6 +125,8 @@ public function __construct(RendererInterface $renderer = null, $layout = null)
      * the constructor.
      *
      * @param array|ModelInterface|object $params
+     *
+     * @return string
      */
     public function render(string $name, $params = []) : string
     {
@@ -191,10 +193,21 @@ private function createModel($name, $params)
     /**
      * Do a recursive, depth-first rendering of a view model.
      *
-     * @throws Exception\RenderingException if it encounters a terminal child.
+     * @param ModelInterface      $model
+     * @param RendererInterface   $renderer
+     * @param ModelInterface|null $root
+     *
+     * @return string
      */
-    private function renderModel(ModelInterface $model, RendererInterface $renderer) : string
-    {
+    private function renderModel(
+        ModelInterface $model,
+        RendererInterface $renderer,
+        ModelInterface $root = null
+    ) : string {
+        if (! $root) {
+            $root = $model;
+        }
+
         foreach ($model as $child) {
             if ($child->terminate()) {
                 throw new Exception\RenderingException('Cannot render; encountered a child marked terminal');
@@ -206,6 +219,12 @@ private function renderModel(ModelInterface $model, RendererInterface $renderer)
             }
 
             $child  = $this->mergeViewModel($child->getTemplate(), $child);
+
+            if ($child !== $root) {
+                $viewModelHelper = $renderer->plugin('view_model');
+                $viewModelHelper->setRoot($root);
+            }
+
             $result = $this->renderModel($child, $renderer);
 
             if ($child->isAppend()) {

test/TestAsset/zendview-change-layout.phtml

@@ -0,0 +1,3 @@
+<?php $this->layout('zendview-layout2'); ?>
+
+<h1>This is a template file for ZendView</h1>

test/ZendViewRendererTest.php

@@ -606,4 +606,23 @@ public function testRenderChildWithDefaultParameter()
 
         static::assertEquals($content, $result);
     }
+
+    public function testChangeLayoutInTemplate()
+    {
+        $renderer = new ZendViewRenderer();
+        $renderer->addPath(__DIR__ . '/TestAsset');
+
+        $viewModelChild = new ViewModel();
+        $viewModelChild->setTemplate('zendview-change-layout');
+
+        $result = $renderer->render('zendview-change-layout', ['layout' => 'zendview-layout']);
+
+        $contentChild = file_get_contents(__DIR__ . '/TestAsset/zendview-change-layout.phtml');
+        $contentChild = str_replace("<?php \$this->layout('zendview-layout2'); ?>\n", '', $contentChild);
+
+        $content = file_get_contents(__DIR__ . '/TestAsset/zendview-layout2.phtml');
+        $content = str_replace("<?= \$this->content ?>\n", $contentChild, $content);
+
+        static::assertEquals($content, $result);
+    }
 }