微调

app/Http/Controllers/ArticleController.php

@@ -21,6 +21,10 @@ class ArticleController extends Controller
 
     public function show(Article $article)
     {
+        if ($article->url) {
+            return redirect($article->url);
+        }
+
         $category = $article->category;
 
         return view('articles.show', compact('article', 'category'));