/**
  * Update an existing blog article
  */
 public function article_update()
 {
     $view = $this->getView();
     $request = $this->getPageRequest();
     $article = new BlogArticleModel($request->getParameter(0));
     if (!$article->exists()) {
         return View::ERROR_NOTFOUND;
     }
     $blog = $article->getLink('Blog');
     if (!$blog->exists()) {
         return View::ERROR_NOTFOUND;
     }
     $manager = \Core\user()->checkAccess('p:/blog/manage_all');
     $editor = \Core\user()->checkAccess($blog->get('manage_articles_permission ')) || $manager;
     if (!$editor) {
         return View::ERROR_ACCESSDENIED;
     }
     $form = BlogHelper::GetArticleForm($article);
     $view->mastertemplate = 'admin';
     $view->templatename = 'pages/blog/article_create_update.tpl';
     $view->addBreadcrumb($blog->get('title'), $blog->get('rewriteurl'));
     $view->addBreadcrumb($article->get('title'), $article->get('rewriteurl'));
     $view->title = 'Update Blog Article';
     $view->assign('form', $form);
     $view->assign('article', $article);
 }