Default to performing a 301 redirect for URIs with trailing slashes

system/blueprints/config/system.yaml

@@ -139,6 +139,17 @@ form:
                     validate:
                         type: bool
 
+                pages.redirect_trailing_slash:
+                    type: toggle
+                    label: PLUGIN_ADMIN.REDIRECT_TRAILING_SLASH
+                    help: PLUGIN_ADMIN.REDIRECT_TRAILING_SLASH_HELP
+                    highlight: 1
+                    options:
+                        1: PLUGIN_ADMIN.YES
+                        0: PLUGIN_ADMIN.NO
+                    validate:
+                        type: bool
+
         languages:
             type: section
             title: PLUGIN_ADMIN.LANGUAGES

system/config/system.yaml

@@ -46,6 +46,7 @@ pages:
   etag: false                          # Set the etag header tag
   vary_accept_encoding: false          # Add `Vary: Accept-Encoding` header
   redirect_default_route: false        # Automatically redirect to a page's default route
+  redirect_trailing_slash:  true       # Handle automatically or 301 redirect a trailing / URL
 
 cache:
   enabled: true                        # Set to true to enable caching

system/src/Grav/Common/Uri.php

@@ -31,7 +31,6 @@ class Uri
      */
     public function __construct()
     {
-
         $base = 'http://';
         $name = isset($_SERVER['SERVER_NAME']) ? $_SERVER['SERVER_NAME'] : 'localhost';
         $port = isset($_SERVER['SERVER_PORT']) ? $_SERVER['SERVER_PORT'] : 80;
@@ -80,6 +79,11 @@ class Uri
         $config = $grav['config'];
         $language = $grav['language'];
 
+        // If configured to, redirect trailing slash URI's with a 301 redirect
+        if ($config->get('system.pages.redirect_trailing_slash', false) && $this->url != '/' && Utils::endsWith($this->url, '/')) {
+            $grav->redirect(rtrim($this->url, '/'), 301);
+        }
+
         // resets
         $this->paths = [];
         $this->params = [];
@@ -105,6 +109,7 @@ class Uri
             }
         }
 
+
         // split the URL and params
         $bits = parse_url($uri);