From 9264f3aa2d6478f76adcb5743c5ba6bb9ea2bec6 Mon Sep 17 00:00:00 2001
From: Ryan Nowak <nowakra@gmail.com>
Date: Tue, 7 Feb 2017 21:16:40 -0800
Subject: [PATCH] Add TryUpdateModelAsync to pages

---
 .../Infrastructure/PageArgumentBinder.cs      | 29 +++++++++++++++++--
 .../PageModel.cs                              | 21 ++++++++++++++
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/PageArgumentBinder.cs b/src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/PageArgumentBinder.cs
index 4b76587999..4b40ac16cc 100644
--- a/src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/PageArgumentBinder.cs
+++ b/src/Microsoft.AspNetCore.Mvc.RazorPages/Infrastructure/PageArgumentBinder.cs
@@ -9,10 +9,33 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
 {
     public abstract class PageArgumentBinder
     {
-        public async Task<object> BindModelAsync(PageContext context, Type type, object defaultValue, string name)
+        public async Task<object> BindModelAsync(PageContext context, Type type, object @default, string name)
         {
-            var result = await BindAsync(context, value: null, name: name, type: type);
-            return result.IsModelSet ? result.Model : defaultValue;
+            var result = await BindAsync(context, null, name, type);
+            return result.IsModelSet ? result.Model : @default;
+        }
+
+        public Task<T> BindModelAsync<T>(PageContext context, string name)
+        {
+            return BindModelAsync<T>(context, default(T), name);
+        }
+
+        public async Task<T> BindModelAsync<T>(PageContext context, T @default, string name)
+        {
+            var result = await BindAsync(context, null, name, typeof(T));
+            return result.IsModelSet ? (T)result.Model : @default;
+        }
+
+        public async Task<bool> TryUpdateModelAsync<T>(PageContext context, T value)
+        {
+            var result = await BindAsync(context, value, string.Empty, typeof(T));
+            return result.IsModelSet && context.ModelState.IsValid;
+        }
+
+        public async Task<bool> TryUpdateModelAsync<T>(PageContext context, T value, string name)
+        {
+            var result = await BindAsync(context, value, name, typeof(T));
+            return result.IsModelSet && context.ModelState.IsValid;
         }
 
         protected abstract Task<ModelBindingResult> BindAsync(PageContext context, object value, string name, Type type);
diff --git a/src/Microsoft.AspNetCore.Mvc.RazorPages/PageModel.cs b/src/Microsoft.AspNetCore.Mvc.RazorPages/PageModel.cs
index 5688c20d9a..46f1d0e3c5 100644
--- a/src/Microsoft.AspNetCore.Mvc.RazorPages/PageModel.cs
+++ b/src/Microsoft.AspNetCore.Mvc.RazorPages/PageModel.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
 using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
@@ -45,6 +46,26 @@ namespace Microsoft.AspNetCore.Mvc.RazorPages
 
         public ViewDataDictionary ViewData => PageContext?.ViewData;
 
+        protected Task<T> BindAsync<T>(string name)
+        {
+            return Binder.BindModelAsync<T>(PageContext, name);
+        }
+
+        protected Task<T> BindAsync<T>(T @default, string name)
+        {
+            return Binder.BindModelAsync<T>(PageContext, @default, name);
+        }
+
+        protected Task<bool> TryUpdateModelAsync<T>(T value)
+        {
+            return Binder.TryUpdateModelAsync<T>(PageContext, value);
+        }
+
+        protected Task<bool> TryUpdateModelAsync<T>(T value, string name)
+        {
+            return Binder.TryUpdateModelAsync<T>(PageContext, value, name);
+        }
+
         protected IActionResult Redirect(string url)
         {
             return new RedirectResult(url);