Moved validation filtering into ExpressionObserver and out of InstancedBinding, PerspexObject, and the Priority* system. Renamed some methods in this system to be more descriptive.

src/Markup/Perspex.Markup.Xaml/Data/Binding.cs

@@ -131,7 +131,7 @@ namespace Perspex.Markup.Xaml.Data
                 FallbackValue,
                 Priority);
 
-            return new InstancedBinding(subject, Mode, Priority, ValidationMethods);
+            return new InstancedBinding(subject, Mode, Priority);
         }
 
         private static PathInfo ParsePath(string path)
@@ -207,7 +207,7 @@ namespace Perspex.Markup.Xaml.Data
                 var result = new ExpressionObserver(
                     () => target.GetValue(Control.DataContextProperty),
                     path,
-                    update);
+                    update, ValidationMethods);
 
                 return result;
             }
@@ -218,7 +218,7 @@ namespace Perspex.Markup.Xaml.Data
                           .OfType<IPerspexObject>()
                           .Select(x => x.GetObservable(Control.DataContextProperty))
                           .Switch(),
-                    path);
+                    path, ValidationMethods);
             }
         }
 
@@ -228,7 +228,7 @@ namespace Perspex.Markup.Xaml.Data
 
             var result = new ExpressionObserver(
                 ControlLocator.Track(target, elementName),
-                path);
+                path, ValidationMethods);
             return result;
         }
 
@@ -236,7 +236,7 @@ namespace Perspex.Markup.Xaml.Data
         {
             Contract.Requires<ArgumentNullException>(source != null);
 
-            return new ExpressionObserver(source, path);
+            return new ExpressionObserver(source, path, ValidationMethods);
         }
 
         private ExpressionObserver CreateTemplatedParentObserver(

src/Markup/Perspex.Markup/Data/ExpressionObserver.cs

@@ -47,18 +47,20 @@ namespace Perspex.Markup.Data
         private IDisposable _updateSubscription;
         private int _count;
         private readonly ExpressionNode _node;
+        private ValidationMethods _methods;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="ExpressionObserver"/> class.
         /// </summary>
         /// <param name="root">The root object.</param>
         /// <param name="expression">The expression.</param>
-        public ExpressionObserver(object root, string expression)
+        /// <param name="methods">The validation methods to enable on this observer.</param>
+        public ExpressionObserver(object root, string expression, ValidationMethods methods = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(expression != null);
 
             _root = new WeakReference(root);
-
+            _methods = methods;
             if (!string.IsNullOrWhiteSpace(expression))
             {
                 _node = ExpressionNodeBuilder.Build(expression);
@@ -72,13 +74,14 @@ namespace Perspex.Markup.Data
         /// </summary>
         /// <param name="rootObservable">An observable which provides the root object.</param>
         /// <param name="expression">The expression.</param>
-        public ExpressionObserver(IObservable<object> rootObservable, string expression)
+        /// <param name="methods">The validation methods to enable on this observer.</param>
+        public ExpressionObserver(IObservable<object> rootObservable, string expression, ValidationMethods methods = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(rootObservable != null);
             Contract.Requires<ArgumentNullException>(expression != null);
 
             _rootObservable = rootObservable;
-
+            _methods = methods;
             if (!string.IsNullOrWhiteSpace(expression))
             {
                 _node = ExpressionNodeBuilder.Build(expression);
@@ -93,10 +96,12 @@ namespace Perspex.Markup.Data
         /// <param name="rootGetter">A function which gets the root object.</param>
         /// <param name="expression">The expression.</param>
         /// <param name="update">An observable which triggers a re-read of the getter.</param>
+        /// <param name="methods">The validation methods to enable on this observer.</param>
         public ExpressionObserver(
             Func<object> rootGetter, 
             string expression,
-            IObservable<Unit> update)
+            IObservable<Unit> update,
+            ValidationMethods methods = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(rootGetter != null);
             Contract.Requires<ArgumentNullException>(expression != null);
@@ -104,7 +109,7 @@ namespace Perspex.Markup.Data
 
             _rootGetter = rootGetter;
             _update = update;
-
+            _methods = methods;
             if (!string.IsNullOrWhiteSpace(expression))
             {
                 _node = ExpressionNodeBuilder.Build(expression);
@@ -216,8 +221,8 @@ namespace Perspex.Markup.Data
                 {
                     source = source.TakeUntil(_update.LastOrDefaultAsync());
                 }
-
+                var validationFiltered = source.Where(o => (o as ValidationStatus)?.Match(_methods) ?? true);
-                var subscription = source.Subscribe(observer);
+                var subscription = validationFiltered.Subscribe(observer);
 
                 return Disposable.Create(() =>
                 {

src/Perspex.Base/Data/BindingOperations.cs

@@ -44,10 +44,10 @@ namespace Perspex.Data
             {
                 case BindingMode.Default:
                 case BindingMode.OneWay:
-                    return target.Bind(property, binding.Observable ?? binding.Subject, binding.Priority, binding.ValidationMethods);
+                    return target.Bind(property, binding.Observable ?? binding.Subject, binding.Priority);
                 case BindingMode.TwoWay:
                     return new CompositeDisposable(
-                        target.Bind(property, binding.Subject, binding.Priority, binding.ValidationMethods),
+                        target.Bind(property, binding.Subject, binding.Priority),
                         target.GetObservable(property).Subscribe(binding.Subject));
                 case BindingMode.OneTime:
                     var source = binding.Subject ?? binding.Observable;

src/Perspex.Base/Data/InstancedBinding.cs

@@ -29,16 +29,13 @@ namespace Perspex.Data
         /// <param name="value">
         /// The value used for the <see cref="BindingMode.OneTime"/> binding.
         /// </param>
-        /// <param name="methods">The validation methods for this binding.</param>
         /// <param name="priority">The binding priority.</param>
         public InstancedBinding(object value,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue)
-            ValidationMethods methods = ValidationMethods.None)
         {
             Mode = BindingMode.OneTime;
             Priority = priority;
             Value = value;
-            ValidationMethods = methods;
         }
 
         /// <summary>
@@ -47,12 +44,10 @@ namespace Perspex.Data
         /// <param name="observable">The observable for a one-way binding.</param>
         /// <param name="mode">The binding mode.</param>
         /// <param name="priority">The binding priority.</param>
-        /// <param name="methods">The validation methods for this binding.</param>
         public InstancedBinding(
             IObservable<object> observable, 
             BindingMode mode = BindingMode.OneWay,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue)
-            ValidationMethods methods = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(observable != null);
 
@@ -66,7 +61,6 @@ namespace Perspex.Data
             Mode = mode;
             Priority = priority;
             Observable = observable;
-            ValidationMethods = methods;
         }
 
         /// <summary>
@@ -75,19 +69,16 @@ namespace Perspex.Data
         /// <param name="subject">The subject for a two-way binding.</param>
         /// <param name="mode">The binding mode.</param>
         /// <param name="priority">The binding priority.</param>
-        /// <param name="methods">The validation methods for this binding.</param>
         public InstancedBinding(
             ISubject<object> subject,
             BindingMode mode = BindingMode.OneWay,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue)
-            ValidationMethods methods = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(subject != null);
 
             Mode = mode;
             Priority = priority;
             Subject = subject;
-            ValidationMethods = methods;
         }
 
         /// <summary>
@@ -114,10 +105,5 @@ namespace Perspex.Data
         /// Gets the subject for a two-way binding.
         /// </summary>
         public ISubject<object> Subject { get; }
-
-        /// <summary>
-        /// Gets the validation methods for this binding.
-        /// </summary>
-        public ValidationMethods ValidationMethods { get; }
     }
 }

src/Perspex.Base/IPerspexObject.cs

@@ -67,15 +67,13 @@ namespace Perspex
         /// <param name="property">The property.</param>
         /// <param name="source">The observable.</param>
         /// <param name="priority">The priority of the binding.</param>
-        /// <param name="validation">The validation methods of the binding.</param>
         /// <returns>
         /// A disposable which can be used to terminate the binding.
         /// </returns>
         IDisposable Bind(
             PerspexProperty property,
             IObservable<object> source,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue);
-            ValidationMethods validation = ValidationMethods.None);
 
         /// <summary>
         /// Binds a <see cref="PerspexProperty"/> to an observable.
@@ -84,14 +82,12 @@ namespace Perspex
         /// <param name="property">The property.</param>
         /// <param name="source">The observable.</param>
         /// <param name="priority">The priority of the binding.</param>
-        /// <param name="validation">The validation methods of the binding.</param>
         /// <returns>
         /// A disposable which can be used to terminate the binding.
         /// </returns>
         IDisposable Bind<T>(
             PerspexProperty<T> property,
             IObservable<T> source,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue);
-            ValidationMethods validation = ValidationMethods.None);
     }
 }

src/Perspex.Base/IPriorityValueOwner.cs

@@ -23,6 +23,6 @@ namespace Perspex
         /// </summary>
         /// <param name="sender">The source of the change.</param>
         /// <param name="status">The validation status.</param>
-        void ValidationChanged(PriorityValue sender, ValidationStatus status);
+        void DataValidationChanged(PriorityValue sender, ValidationStatus status);
     }
 }

src/Perspex.Base/PerspexObject.cs

@@ -375,15 +375,13 @@ namespace Perspex
         /// <param name="property">The property.</param>
         /// <param name="source">The observable.</param>
         /// <param name="priority">The priority of the binding.</param>
-        /// <param name="validation">The validation methods of the binding.</param>
         /// <returns>
         /// A disposable which can be used to terminate the binding.
         /// </returns>
         public IDisposable Bind(
             PerspexProperty property,
             IObservable<object> source,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue)
-            ValidationMethods validation = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(property != null);
             VerifyAccess();
@@ -412,8 +410,7 @@ namespace Perspex
                     .Subscribe(x => DirectBindingSet(property, x));
                 validationSubcription = source
                     .OfType<ValidationStatus>()
-                    .Where(v => v.Match(validation))
+                    .Subscribe(x => DataValidation(property, x));
-                    .Subscribe(x => ValidationChanged(property, x));
 
                 s_directBindings.Add(subscription);
 
@@ -447,7 +444,7 @@ namespace Perspex
                     GetDescription(source),
                     priority);
 
-                return v.Add(source, (int)priority, validation);
+                return v.Add(source, (int)priority);
             }
         }
 
@@ -458,19 +455,17 @@ namespace Perspex
         /// <param name="property">The property.</param>
         /// <param name="source">The observable.</param>
         /// <param name="priority">The priority of the binding.</param>
-        /// <param name="validation">The validation methods of the binding.</param>
         /// <returns>
         /// A disposable which can be used to terminate the binding.
         /// </returns>
         public IDisposable Bind<T>(
             PerspexProperty<T> property,
             IObservable<T> source,
-            BindingPriority priority = BindingPriority.LocalValue,
+            BindingPriority priority = BindingPriority.LocalValue)
-            ValidationMethods validation = ValidationMethods.None)
         {
             Contract.Requires<ArgumentNullException>(property != null);
 
-            return Bind((PerspexProperty)property, source.Select(x => (object)x), priority);
+            return Bind(property, source.Select(x => (object)x), priority);
         }
 
         /// <summary>
@@ -517,13 +512,18 @@ namespace Perspex
         }
 
         /// <inheritdoc/>
-        void IPriorityValueOwner.ValidationChanged(PriorityValue sender, ValidationStatus status)
+        void IPriorityValueOwner.DataValidationChanged(PriorityValue sender, ValidationStatus status)
         {
             var property = sender.Property;
-            ValidationChanged(property, status);
+            DataValidation(property, status);
         }
 
-        protected virtual void ValidationChanged(PerspexProperty property, ValidationStatus status)
+        /// <summary>
+        /// Called when the validation state on a tracked property is changed.
+        /// </summary>
+        /// <param name="property">The property whose validation state changed.</param>
+        /// <param name="status">The new validation state.</param>
+        protected virtual void DataValidation(PerspexProperty property, ValidationStatus status)
         {
 
         }

src/Perspex.Base/PriorityBindingEntry.cs

@@ -13,7 +13,6 @@ namespace Perspex
     {
         private PriorityLevel _owner;
         private IDisposable _subscription;
-        private ValidationMethods _validation;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="PriorityBindingEntry"/> class.
@@ -23,11 +22,10 @@ namespace Perspex
         /// The binding index. Later bindings should have higher indexes.
         /// </param>
         /// <param name="validation">The validation settings for the binding.</param>
-        public PriorityBindingEntry(PriorityLevel owner, int index, ValidationMethods validation)
+        public PriorityBindingEntry(PriorityLevel owner, int index)
         {
             _owner = owner;
             Index = index;
-            _validation = validation;
         }
 
         /// <summary>
@@ -106,10 +104,7 @@ namespace Perspex
 
             if (validationStatus != null)
             {
-                if (validationStatus.Match(_validation))
+                _owner.Validation(this, validationStatus);
-                {
-                    _owner.Validation(this, validationStatus);
-                }
             }
             else if (bindingError == null || bindingError.UseFallbackValue)
             {

src/Perspex.Base/PriorityLevel.cs

@@ -99,11 +99,11 @@ namespace Perspex
         /// <param name="binding">The binding to add.</param>
         /// <param name="validation">Validation settings for the binding.</param>
         /// <returns>A disposable used to remove the binding.</returns>
-        public IDisposable Add(IObservable<object> binding, ValidationMethods validation)
+        public IDisposable Add(IObservable<object> binding)
         {
             Contract.Requires<ArgumentNullException>(binding != null);
 
-            var entry = new PriorityBindingEntry(this, _nextIndex++, validation);
+            var entry = new PriorityBindingEntry(this, _nextIndex++);
             var node = Bindings.AddFirst(entry);
 
             entry.Start(binding);

src/Perspex.Base/PriorityValue.cs

@@ -81,9 +81,9 @@ namespace Perspex
         /// <returns>
         /// A disposable that will remove the binding.
         /// </returns>
-        public IDisposable Add(IObservable<object> binding, int priority, ValidationMethods validation = ValidationMethods.None)
+        public IDisposable Add(IObservable<object> binding, int priority)
         {
-            return GetLevel(priority).Add(binding, validation);
+            return GetLevel(priority).Add(binding);
         }
 
         /// <summary>
@@ -186,7 +186,7 @@ namespace Perspex
         /// <param name="validationStatus">The validation status.</param>
         public void LevelValidation(PriorityLevel priorityLevel, ValidationStatus validationStatus)
         {
-            _owner.ValidationChanged(this, validationStatus);
+            _owner.DataValidationChanged(this, validationStatus);
         }
 
         /// <summary>

src/Perspex.Controls/Control.cs

@@ -423,9 +423,10 @@ namespace Perspex.Controls
             }
         }
 
-        protected override void ValidationChanged(PerspexProperty property, ValidationStatus status)
+        /// <inheritdoc/>
+        protected override void DataValidation(PerspexProperty property, ValidationStatus status)
         {
-            base.ValidationChanged(property, status);
+            base.DataValidation(property, status);
             ValidationStatus = status;
         }
 

tests/Perspex.Markup.Xaml.UnitTests/Data/BindingTests_TemplatedParent.cs

@@ -32,8 +32,7 @@ namespace Perspex.Markup.Xaml.UnitTests.Data
             target.Verify(x => x.Bind(
                 TextBox.TextProperty, 
                 It.IsAny<IObservable<object>>(), 
-                BindingPriority.TemplatedParent,
+                BindingPriority.TemplatedParent));
-                ValidationMethods.None));
         }
 
         [Fact]
@@ -53,8 +52,7 @@ namespace Perspex.Markup.Xaml.UnitTests.Data
             target.Verify(x => x.Bind(
                 TextBox.TextProperty,
                 It.IsAny<ISubject<object>>(),
-                BindingPriority.TemplatedParent,
+                BindingPriority.TemplatedParent));
-                ValidationMethods.None));
         }
 
         private Mock<IControl> CreateTarget(

tests/Perspex.Styling.UnitTests/SelectorTests_Child.cs

@@ -129,7 +129,7 @@ namespace Perspex.Styling.UnitTests
                 throw new NotImplementedException();
             }
 
-            public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority, ValidationMethods validation)
+            public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority)
             {
                 throw new NotImplementedException();
             }
@@ -139,7 +139,7 @@ namespace Perspex.Styling.UnitTests
                 throw new NotImplementedException();
             }
 
-            public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+            public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue)
             {
                 throw new NotImplementedException();
             }

tests/Perspex.Styling.UnitTests/SelectorTests_Descendent.cs

@@ -160,7 +160,7 @@ namespace Perspex.Styling.UnitTests
                 throw new NotImplementedException();
             }
 
-            public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+            public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue)
             {
                 throw new NotImplementedException();
             }
@@ -170,7 +170,7 @@ namespace Perspex.Styling.UnitTests
                 throw new NotImplementedException();
             }
 
-            public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+            public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue)
             {
                 throw new NotImplementedException();
             }

tests/Perspex.Styling.UnitTests/TestControlBase.cs

@@ -62,12 +62,12 @@ namespace Perspex.Styling.UnitTests
             throw new NotImplementedException();
         }
 
-        public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+        public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue)
         {
             throw new NotImplementedException();
         }
 
-        public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+        public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue)
         {
             throw new NotImplementedException();
         }

tests/Perspex.Styling.UnitTests/TestTemplatedControl.cs

@@ -57,12 +57,12 @@ namespace Perspex.Styling.UnitTests
             throw new NotImplementedException();
         }
 
-        public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+        public IDisposable Bind(PerspexProperty property, IObservable<object> source, BindingPriority priority = BindingPriority.LocalValue)
         {
             throw new NotImplementedException();
         }
 
-        public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue, ValidationMethods validation = ValidationMethods.None)
+        public IDisposable Bind<T>(PerspexProperty<T> property, IObservable<T> source, BindingPriority priority = BindingPriority.LocalValue)
         {
             throw new NotImplementedException();
         }