Merge pull request #51 from bwaidelich/feature-render-callbacks

FEATURE: Configurable Form Element render callbacks
neos · Jul 31, 2017 · 502878f · 502878f
2 parents bc3c7d1 + 39d5bf9
commit 502878f
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diff --git a/Classes/Core/Renderer/FluidFormRenderer.php b/Classes/Core/Renderer/FluidFormRenderer.php
@@ -192,6 +192,7 @@ public function renderRenderable(\Neos\Form\Core\Model\Renderable\RootRenderable
         }
 
         $this->baseRenderingContext->setTemplatePaths($currentTemplatePathsResolver);
+        $output = $this->formRuntime->invokeRenderCallbacks($output, $renderable);
         return $output;
     }
 

diff --git a/Classes/Core/Runtime/FormRuntime.php b/Classes/Core/Runtime/FormRuntime.php
@@ -13,6 +13,7 @@
 
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Mvc\ActionRequest;
+use Neos\Form\Core\Model\Renderable\RootRenderableInterface;
 
 /**
  * This class implements the *runtime logic* of a form, i.e. deciding which
@@ -117,6 +118,11 @@ class FormRuntime implements \Neos\Form\Core\Model\Renderable\RootRenderableInte
      */
     protected $flashMessageContainer;
 
+    /**
+     * @var callable[]
+     */
+    protected $renderCallbacks = [];
+
     /**
      * @param \Neos\Form\Core\Model\FormDefinition $formDefinition
      * @param \Neos\Flow\Mvc\ActionRequest $request
@@ -605,4 +611,31 @@ public function getFormDefinition()
     public function beforeRendering(\Neos\Form\Core\Runtime\FormRuntime $formRuntime)
     {
     }
+
+    /**
+     * Registers a callback that is called just before a Form Element is rendered.
+     * The callback will be invoked with the rendered element and an instance of the RootRenderableInterface as
+     * arguments and is expected to return the (possibly altered) rendered element
+     *
+     * @param callable $callback
+     * @return void
+     * @api
+     */
+    public function registerRenderCallback(callable $callback)
+    {
+        $this->renderCallbacks[] = $callback;
+    }
+
+    /**
+     * @param string $renderedElement
+     * @param RootRenderableInterface $renderable
+     * @return string
+     */
+    public function invokeRenderCallbacks($renderedElement, RootRenderableInterface $renderable)
+    {
+        foreach ($this->renderCallbacks as $renderCallback) {
+            $renderedElement = call_user_func($renderCallback, $renderedElement, $renderable);
+        }
+        return $renderedElement;
+    }
 }
diff --git a/Documentation/extending-form-api.rst b/Documentation/extending-form-api.rst
@@ -164,6 +164,7 @@ list. A Form Element Renderer must implement the ``RendererInterface`` interface
 	    * @return string
 	    */
 	   public function renderRenderable(\Neos\Form\Core\Model\Renderable\RootRenderableInterface $renderable) {
+	      $renderable->beforeRendering($this->formRuntime);
 	      $items = array();
 	      if ($renderable instanceof \Neos\Form\Core\Model\FormElementInterface) {
 	         $elementProperties = $renderable->getProperties();
@@ -177,9 +178,13 @@ list. A Form Element Renderer must implement the ``RendererInterface`` interface
 	         $content .= sprintf('<li>%s</li>', htmlspecialchars($item));
 	      }
 	      $content .= '</ul>';
+	      $content = $this->formRuntime->invokeRenderCallbacks($content, $renderable);
 	      return $content;
 	   }
 	}
 
+.. note::  Don't forget to invoke ``RootRenderableInterface::beforeRendering()`` and ``FormRuntime::invokeRenderCallbacks()``
+   as shown above.
+
 .. tip:: If you write your own Renderer make sure to sanitize values with ``htmlspecialchars()`` before outputting
    them to prevent invalid HTML and XSS vulnerabilities.