Behave better if s:View.Model used on a bad container

Fixes #6
canton7 · Jun 2, 2015 · 5e412af · 5e412af
1 parent 9719289
commit 5e412af
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Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/Stylet/Xaml/View.cs b/Stylet/Xaml/View.cs
@@ -3,6 +3,7 @@
 using System.Windows;
 using System.Windows.Data;
 using System.Windows.Markup;
+using System.Reflection;
 
 namespace Stylet.Xaml
 {
@@ -22,8 +23,6 @@ public class View : DependencyObject
         /// </summary>
         public static readonly object InitialActionTarget = new object();
 
-        private static readonly ContentPropertyAttribute defaultContentProperty = new ContentPropertyAttribute("Content");
-
         /// <summary>
         /// Get the ActionTarget associated with the given object
         /// </summary>
@@ -115,9 +114,13 @@ public static void SetModel(DependencyObject obj, object value)
         public static void SetContentProperty(DependencyObject targetLocation, UIElement view)
         {
             var type = targetLocation.GetType();
-            var contentProperty = Attribute.GetCustomAttributes(type, true).OfType<ContentPropertyAttribute>().FirstOrDefault() ?? defaultContentProperty;
-
-            type.GetProperty(contentProperty.Name).SetValue(targetLocation, view, null);
+            var attribute = type.GetCustomAttribute<ContentPropertyAttribute>();
+            // No attribute? Try a property called 'Content'...
+            string propertyName = attribute != null ? attribute.Name : "Content";
+            var property = type.GetProperty(propertyName);
+            if (property == null)
+                throw new InvalidOperationException(String.Format("Unable to find a Content property on type {0}. Make sure you're using 's:View.Model' on a suitable container, e.g. a ContentControl", type.Name));
+            property.SetValue(targetLocation, view);
         }
 
         // Stop someone from instantiating us

diff --git a/StyletUnitTests/ViewTests.cs b/StyletUnitTests/ViewTests.cs
@@ -93,6 +93,15 @@ public void SetsContentControlContentProperty()
             Assert.AreEqual(obj.Content, view);
         }
 
+        [Test]
+        public void SetContentControlThrowsIfNoContentProperty()
+        {
+            var obj = new DependencyObject();
+            var view = new UIElement();
+
+            Assert.Throws<InvalidOperationException>(() => View.SetContentProperty(obj, view));
+        }
+
         [Test]
         public void SettingModelThrowsExceptionIfViewManagerNotSet()
         {