Added missing shortcut addAjaxBlock() and isAjax() method

- Better management of ajax requests in controllers

src/Controller/AjaxcomSymfony4Trait.php

@@ -76,7 +76,7 @@ protected function render(string $view, array $parameters = array(), Response $r
     {
         $request = $this->requestStack->getMasterRequest();
 
-        if ($request->server->get(Ajaxcom::AJAX_COM_HEADER, false)) {
+        if ($this->isAjax()) {
             return $this->ajaxcom->handle($view, $parameters);
         }
 
@@ -97,6 +97,13 @@ protected function dontRenderAjaxBlock(string $id): self
         return $this;
     }
 
+    protected function addAjaxBlock(string $id): self
+    {
+        $this->ajaxcomAddBlocks->add($id);
+
+        return $this;
+    }
+
     protected function appendAjaxBlock(string $id): self
     {
         $this->ajaxcomAppendBlocks->add($id);
@@ -145,4 +152,13 @@ protected function prependAjaxBlock(string $id): self
 
         return $this;
     }
+
+    protected function isAjax(): bool
+    {
+        /** @var Request $request */
+        $request = $this->requestStack->getMasterRequest();
+        $isAjax = $request->server->getBoolean(Ajaxcom::AJAX_COM_HEADER, false);
+
+        return $isAjax;
+    }
 }