added tag for boolean evaluation of user role

Sources/AdminPanel/Providers/AdminPanelProvider.swift

@@ -137,7 +137,8 @@ public final class AdminPanelProvider<U: AdminPanelUserType>: Provider {
             "adminpanel:sidebar:heading": SidebarHeadingTag(),
             "adminpanel:sidebar:menuitem": SidebarMenuItemTag(),
             "adminpanel:user": CurrentUserTag<U>(),
-            "adminpanel:user:requireRole": RequireRoleTag<U>()
+            "adminpanel:user:requireRole": RequireRoleTag<U>(),
+            "adminpanel:user:roleAllows": RoleAllowsTag<U>()
         ])
 
         return .done(on: container)

Sources/AdminPanel/Tags/RoleAllowsTag.swift

@@ -0,0 +1,28 @@
+import Leaf
+import Authentication
+import Sugar
+
+public final class RoleAllowsTag<U: AdminPanelUserType>: TagRenderer {
+    public func render(tag: TagContext) throws -> Future<TemplateData> {
+        try tag.requireParameterCount(1)
+
+        let container = try tag.container.make(
+            CurrentUserContainer<U>.self
+        )
+
+        guard
+            let roleString: String = tag.parameters[0].string,
+            let requiredRole = U.Role.init(roleString)
+        else {
+            throw tag.error(reason: "Invalid role requirement")
+        }
+
+        guard
+            let userRole = container.user?.role
+        else {
+             return tag.future(.bool(false))
+        }
+
+        return tag.future(.bool(userRole >= requiredRole))
+    }
+}