Simplify navbar implementation - this will also allow seamlessly adding a third, centred nav if desired

src/Foundation.hs

@@ -97,8 +97,7 @@ instance Yesod App where
         -- Get the breadcrumbs, as defined in the YesodBreadcrumbs instance.
         (title, parents) <- breadcrumbs
 
-        let navbarLeftMenuItems = leftMenuItems muser
-            navbarRightMenuItems = rightMenuItems muser
+        let navbars = [leftMenuItems, rightMenuItems] <*> [muser]
 
         -- We break up the default layout into two components:
         -- default-layout is the contents of the body tag, and

templates/default-layout.cassius

@@ -15,6 +15,8 @@ body
     padding-bottom: 1em
     display: flex
     justify-content: space-evenly
+#navbar
+  justify-content: space-between
 .breadcrumb
   background-color: #404449
   border-radius: 0

templates/default-layout.hamlet

@@ -6,15 +6,12 @@
             <span .navbar-toggler-icon>
 
         <div #navbar .collapse.navbar-collapse>
-            <ul .navbar-nav.mr-auto>
-                $forall MenuItem label route <- navbarLeftMenuItems
-                    <li .nav-item :Just route == mcurrentRoute:.active>
-                        <a .nav-link href=@{route}>#{label}
+            $forall bar <- navbars
+                <ul .navbar-nav>
+                    $forall MenuItem label route <- bar
+                        <li .nav-item :Just route == mcurrentRoute:.active>
+                            <a .nav-link href=@{route}>#{label}
 
-            <ul .navbar-nav>
-                $forall MenuItem label route <- navbarRightMenuItems
-                    <li .nav-item :Just route == mcurrentRoute:.active>
-                        <a .nav-link href=@{route}>#{label}
     $if not $ null parents
         <ul .breadcrumb>
             $forall bc <- parents