maui-linux/Xamarin.Forms.Xaml/ApplyPropertiesVisitor.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Xml;
using Xamarin.Forms.Internals;
using Xamarin.Forms.Xaml.Diagnostics;
using Xamarin.Forms.Xaml.Internals;

using static System.String;

namespace Xamarin.Forms.Xaml
{
	class ApplyPropertiesVisitor : IXamlNodeVisitor
	{
		public static readonly IList<XmlName> Skips = new List<XmlName> {
			XmlName.xKey,
			XmlName.xTypeArguments,
			XmlName.xArguments,
			XmlName.xFactoryMethod,
			XmlName.xName,
			XmlName.xDataType
		};

		public ApplyPropertiesVisitor(HydrationContext context, bool stopOnResourceDictionary = false)
		{
			Context = context;
			StopOnResourceDictionary = stopOnResourceDictionary;
		}

		Dictionary<INode, object> Values => Context.Values;
		HydrationContext Context { get; }

		public TreeVisitingMode VisitingMode => TreeVisitingMode.BottomUp;
		public bool StopOnDataTemplate => true;
		public bool StopOnResourceDictionary { get; }
		public bool VisitNodeOnDataTemplate => true;
		public bool SkipChildren(INode node, INode parentNode) => false;
		public bool IsResourceDictionary(ElementNode node) => Context.Types.TryGetValue(node, out var type) && typeof(ResourceDictionary).IsAssignableFrom(type);

		public void Visit(ValueNode node, INode parentNode)
		{
			var parentElement = parentNode as IElementNode;
			var value = Values [node];
			if (!Values.TryGetValue(parentNode, out var source) && Context.ExceptionHandler != null)
				return;

			XmlName propertyName;

			if (TryGetPropertyName(node, parentNode, out propertyName)) {
				if (TrySetRuntimeName(propertyName, source, value, node))
					return;
				if (Skips.Contains(propertyName))
					return;
				if (parentElement.SkipProperties.Contains(propertyName))
					return;
				if (propertyName.Equals(XamlParser.McUri, "Ignorable"))
					return;
				SetPropertyValue(source, propertyName, value, Context.RootElement, node, Context, node);
			} else if (IsCollectionItem(node, parentNode) && parentNode is IElementNode) {
				// Collection element, implicit content, or implicit collection element.
				var contentProperty = GetContentPropertyName(Context.Types[parentElement].GetTypeInfo());
				if (contentProperty != null) {
					var name = new XmlName(((ElementNode)parentNode).NamespaceURI, contentProperty);
					if (Skips.Contains(name))
						return;
					if (parentElement.SkipProperties.Contains(propertyName))
						return;
					SetPropertyValue(source, name, value, Context.RootElement, node, Context, node);
				}
			}
		}

		public void Visit(MarkupNode node, INode parentNode)
		{
		}

		public void Visit(ElementNode node, INode parentNode)
		{
			XmlName propertyName;
			if (TryGetPropertyName(node, parentNode, out propertyName) && propertyName == XmlName._CreateContent) {
				var s0 = Values[parentNode];
				if (s0 is ElementTemplate) {
					SetTemplate(s0 as ElementTemplate, node);
					return;
				}
			}

			var parentElement = parentNode as IElementNode;
			propertyName = XmlName.Empty;

			//Simplify ListNodes with single elements
			var pList = parentNode as ListNode;
			if (pList != null && pList.CollectionItems.Count == 1) {
				propertyName = pList.XmlName;
				parentNode = parentNode.Parent;
				parentElement = parentNode as IElementNode;
			}

			if (!Values.TryGetValue(node, out var value) && Context.ExceptionHandler != null)
				return;

			if (propertyName != XmlName.Empty || TryGetPropertyName(node, parentNode, out propertyName)) {
				if (Skips.Contains(propertyName))
					return;
				if (parentElement.SkipProperties.Contains(propertyName))
					return;

				if (!Values.TryGetValue(parentNode, out var source) && Context.ExceptionHandler != null)
					return;
				ProvideValue(ref value, node, source, propertyName);
				SetPropertyValue(source, propertyName, value, Context.RootElement, node, Context, node);
			}
			else if (IsCollectionItem(node, parentNode) && parentNode is IElementNode) {
				if (!Values.TryGetValue(parentNode, out var source) && Context.ExceptionHandler != null)
					return;
				ProvideValue(ref value, node, source, XmlName.Empty);
				string contentProperty;
				Exception xpe = null;
				var xKey = node.Properties.ContainsKey(XmlName.xKey) ? ((ValueNode)node.Properties[XmlName.xKey]).Value as string : null;

				//ResourceDictionary
				if (xpe == null && TryAddToResourceDictionary(source as ResourceDictionary, value, xKey, node, out xpe))
					return;

				// Collection element, implicit content, or implicit collection element.
				if (xpe == null && typeof(IEnumerable).IsAssignableFrom(Context.Types[parentElement]) && Context.Types[parentElement].GetRuntimeMethods().Any(mi => mi.Name == "Add" && mi.GetParameters().Length == 1)) {
					var addMethod =
						Context.Types[parentElement].GetRuntimeMethods().First(mi => mi.Name == "Add" && mi.GetParameters().Length == 1);

					addMethod.Invoke(source, new[] { value });
					return;
				}
				if (xpe == null && (contentProperty = GetContentPropertyName(Context.Types[parentElement].GetTypeInfo())) != null) {
					var name = new XmlName(node.NamespaceURI, contentProperty);
					if (Skips.Contains(name))
						return;
					if (parentElement.SkipProperties.Contains(propertyName))
						return;

					SetPropertyValue(source, name, value, Context.RootElement, node, Context, node);
					return;
				}
				xpe = xpe ?? new XamlParseException($"Can not set the content of {((IElementNode)parentNode).XmlType.Name} as it doesn't have a ContentPropertyAttribute", node);
				if (Context.ExceptionHandler != null)
					Context.ExceptionHandler(xpe);
				else
					throw xpe;
			}
			else if (IsCollectionItem(node, parentNode) && parentNode is ListNode) {
				if (!Values.TryGetValue(parentNode.Parent, out var source) && Context.ExceptionHandler != null)
					return;
				ProvideValue(ref value, node, source, XmlName.Empty);
				var parentList = (ListNode)parentNode;
				if (Skips.Contains(parentList.XmlName))
					return;
				Exception xpe = null;
				var xKey = node.Properties.ContainsKey(XmlName.xKey) ? ((ValueNode)node.Properties[XmlName.xKey]).Value as string : null;

				var collection = GetPropertyValue(source, parentList.XmlName, Context, parentList, out _, out _) as IEnumerable;
				if (collection == null)
					xpe = new XamlParseException($"Property {parentList.XmlName.LocalName} is null or is not IEnumerable", node);

				if (xpe == null && TryAddToResourceDictionary(collection as ResourceDictionary, value, xKey, node, out xpe))
					return;

				MethodInfo addMethod;
				if (xpe == null && (addMethod = collection.GetType().GetRuntimeMethods().First(mi => mi.Name == "Add" && mi.GetParameters().Length == 1)) != null) {
					addMethod.Invoke(collection, new[] { value });
					return;
				}
				xpe = xpe ?? new XamlParseException($"Value of {parentList.XmlName.LocalName} does not have a Add() method", node);
				if (Context.ExceptionHandler != null)
					Context.ExceptionHandler(xpe);
				else
					throw xpe;
			}
		}

		

		public void Visit(RootNode node, INode parentNode)
		{
		}

		public void Visit(ListNode node, INode parentNode)
		{
		}

		public static bool TryGetPropertyName(INode node, INode parentNode, out XmlName name)
		{
			name = default(XmlName);
			var parentElement = parentNode as IElementNode;
			if (parentElement == null)
				return false;
			foreach (var kvp in parentElement.Properties) {
				if (kvp.Value != node)
					continue;
				name = kvp.Key;
				return true;
			}
			return false;
		}

		internal static bool IsCollectionItem(INode node, INode parentNode)
		{
			var parentList = parentNode as IListNode;
			if (parentList == null)
				return false;
			return parentList.CollectionItems.Contains(node);
		}

		internal static string GetContentPropertyName(TypeInfo typeInfo)
		{
			while (typeInfo != null) {
				var propName = GetContentPropertyName(typeInfo.CustomAttributes);
				if (propName != null)
					return propName;
				typeInfo = typeInfo?.BaseType?.GetTypeInfo();
			}
			return null;
		}

		void ProvideValue(ref object value, ElementNode node, object source, XmlName propertyName)
		{
			var markupExtension = value as IMarkupExtension;
			var valueProvider = value as IValueProvider;

			if (markupExtension == null && valueProvider == null)
				return;

			XamlServiceProvider serviceProvider = null;
			if (value.GetType().GetTypeInfo().GetCustomAttribute<AcceptEmptyServiceProviderAttribute>() == null)
				serviceProvider = new XamlServiceProvider(node, Context);

			if (serviceProvider != null && propertyName != XmlName.Empty)
				((XamlValueTargetProvider)serviceProvider.IProvideValueTarget).TargetProperty = GetTargetProperty(source, propertyName, Context, node);

			try {
				if (markupExtension != null)
					value = markupExtension.ProvideValue(serviceProvider);
				else if (valueProvider != null)
					value = valueProvider.ProvideValue(serviceProvider);
			} catch (Exception e) {
				if (Context.ExceptionHandler != null)
					Context.ExceptionHandler(e);
				else
					throw e;
			}
		}

		static string GetContentPropertyName(IEnumerable<CustomAttributeData> attributes)
		{
			var contentAttribute =
				attributes.FirstOrDefault(cad => ContentPropertyAttribute.ContentPropertyTypes.Contains(cad.AttributeType.FullName));
			if (contentAttribute == null || contentAttribute.ConstructorArguments.Count != 1)
				return null;
			if (contentAttribute.ConstructorArguments [0].ArgumentType == typeof(string))
				return (string)contentAttribute.ConstructorArguments [0].Value;
			return null;
		}

		static bool GetRealNameAndType(ref Type elementType, string namespaceURI, ref string localname,
			HydrationContext context, IXmlLineInfo lineInfo)
		{
			var dotIdx = localname.IndexOf('.');
			if (dotIdx > 0) {
				var typename = localname.Substring(0, dotIdx);
				localname = localname.Substring(dotIdx + 1);
				XamlParseException xpe;
				elementType = XamlParser.GetElementType(new XmlType(namespaceURI, typename, null), lineInfo,
					context.RootElement.GetType().GetTypeInfo().Assembly, out xpe);

				if (xpe != null)
					throw xpe;
				return true;
			}
			return false;
		}

		static BindableProperty GetBindableProperty(Type elementType, string localName, IXmlLineInfo lineInfo,
			bool throwOnError = false)
		{
#if NETSTANDARD1_0
			var bindableFieldInfo = elementType.GetFields().FirstOrDefault(fi => fi.Name == localName + "Property");
#else
			// F# does not support public fields, so allow internal (Assembly) as well as public
			const BindingFlags supportedFlags = BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy;
			var bindableFieldInfo = elementType.GetFields(supportedFlags)
												.FirstOrDefault(fi => (fi.IsAssembly || fi.IsPublic) && fi.Name == localName + "Property");
#endif
			Exception exception = null;
			if (exception == null && bindableFieldInfo == null) {
				exception =
					new XamlParseException(
						Format("BindableProperty {0} not found on {1}", localName + "Property", elementType.Name), lineInfo);
			}

			if (exception == null)
				return bindableFieldInfo.GetValue(null) as BindableProperty;
			if (throwOnError)
				throw exception;
			return null;
		}

		static object GetTargetProperty(object xamlelement, XmlName propertyName, HydrationContext context, IXmlLineInfo lineInfo)
		{
			var localName = propertyName.LocalName;
			//If it's an attached BP, update elementType and propertyName
			var bpOwnerType = xamlelement.GetType();
			GetRealNameAndType(ref bpOwnerType, propertyName.NamespaceURI, ref localName, context, lineInfo);
			var property = GetBindableProperty(bpOwnerType, localName, lineInfo, false);

			if (property != null)
				return property;
			
			var elementType = xamlelement.GetType();
			var propertyInfo = elementType.GetRuntimeProperties().FirstOrDefault(p => p.Name == localName);
			return propertyInfo;
		}

		public static void SetPropertyValue(object xamlelement, XmlName propertyName, object value, object rootElement, INode node, HydrationContext context, IXmlLineInfo lineInfo)
		{
			var localName = propertyName.LocalName;
			var serviceProvider = new XamlServiceProvider(node, context);
			Exception xpe = null;
			var xKey = node is IElementNode && ((IElementNode)node).Properties.ContainsKey(XmlName.xKey) ? ((ValueNode)((IElementNode)node).Properties[XmlName.xKey]).Value as string : null;

			//If it's an attached BP, update elementType and propertyName
			var bpOwnerType = xamlelement.GetType();
			var attached = GetRealNameAndType(ref bpOwnerType, propertyName.NamespaceURI, ref localName, context, lineInfo);
			var property = GetBindableProperty(bpOwnerType, localName, lineInfo, false);

			//If the target is an event, connect
			if (xpe == null && TryConnectEvent(xamlelement, localName, attached, value, rootElement, lineInfo, out xpe))
				return;

			//If Value is DynamicResource and it's a BP, SetDynamicResource
			if (xpe == null && TrySetDynamicResource(xamlelement, property, value, lineInfo, out xpe))
				return;

			//If value is BindingBase, SetBinding
			if (xpe == null && TrySetBinding(xamlelement, property, localName, value, lineInfo, out xpe))
				return;

			//If it's a BindableProberty, SetValue
			if (xpe == null && TrySetValue(xamlelement, property, attached, value, lineInfo, serviceProvider, out xpe))
				return;

			//If we can assign that value to a normal property, let's do it
			if (xpe == null && TrySetProperty(xamlelement, localName, value, lineInfo, serviceProvider, context, out xpe))
				return;

			//If it's an already initialized property, add to it
			if (xpe == null && TryAddToProperty(xamlelement, propertyName, value, xKey, lineInfo, serviceProvider, context, out xpe))
				return;

			xpe = xpe ?? new XamlParseException($"Cannot assign property \"{localName}\": Property does not exist, or is not assignable, or mismatching type between value and property", lineInfo);
			if (context.ExceptionHandler != null)
				context.ExceptionHandler(xpe);
			else
				throw xpe;
		}

		public static object GetPropertyValue(object xamlElement, XmlName propertyName, HydrationContext context, IXmlLineInfo lineInfo, out Exception xpe, out object targetProperty)
		{
			var localName = propertyName.LocalName;
			xpe = null;
			targetProperty = null;

			//If it's an attached BP, update elementType and propertyName
			var bpOwnerType = xamlElement.GetType();
			var attached = GetRealNameAndType(ref bpOwnerType, propertyName.NamespaceURI, ref localName, context, lineInfo);
			var property = GetBindableProperty(bpOwnerType, localName, lineInfo, false);

			//If it's a BindableProberty, GetValue
			if (xpe == null && TryGetValue(xamlElement, property, attached, out var value, lineInfo, out xpe, out targetProperty))
				return value;

			//If it's a normal property, get it
			if (xpe == null && TryGetProperty(xamlElement, localName, out value, lineInfo, context, out xpe, out targetProperty))
				return value;

			xpe = xpe ?? new XamlParseException($"Property {localName} is not found or does not have an accessible getter", lineInfo);

			return null;
		}

		static bool TryConnectEvent(object element, string localName, bool attached, object value, object rootElement, IXmlLineInfo lineInfo, out Exception exception)
		{
			exception = null;

			if (attached)
				return false;

			var elementType = element.GetType();
			var eventInfo = elementType.GetRuntimeEvent(localName);
			var stringValue = value as string;

			if (eventInfo == null || IsNullOrEmpty(stringValue))
				return false;

			foreach (var mi in rootElement.GetType().GetRuntimeMethods()) {
				if (mi.Name == (string)value) {
					try {
						eventInfo.AddEventHandler(element, mi.CreateDelegate(eventInfo.EventHandlerType, mi.IsStatic ? null : rootElement));
						return true;
					} catch (ArgumentException) {
						// incorrect method signature
					}
				}
			}

			exception = new XamlParseException($"No method {value} with correct signature found on type {rootElement.GetType()}", lineInfo);
			return false;
		}

		static bool TrySetDynamicResource(object element, BindableProperty property, object value, IXmlLineInfo lineInfo, out Exception exception)
		{
			exception = null;

			var elementType = element.GetType();
			var dynamicResource = value as DynamicResource;
			var bindable = element as BindableObject;

			if (dynamicResource == null || property == null)
				return false;

			if (bindable == null) {
				exception = new XamlParseException($"{elementType.Name} is not a BindableObject", lineInfo);
				return false;
			}

			bindable.SetDynamicResource(property, dynamicResource.Key);
			return true;
		}

		static bool TrySetBinding(object element, BindableProperty property, string localName, object value, IXmlLineInfo lineInfo, out Exception exception)
		{
			exception = null;

			var elementType = element.GetType();
			var binding = value.ConvertTo(typeof(BindingBase),pinfoRetriever:null,serviceProvider:null, exception:out exception) as BindingBase;
			if (exception != null)
				return false;
			var bindable = element as BindableObject;
			var nativeBindingService = DependencyService.Get<INativeBindingService>();

			if (binding == null)
				return false;

			if (bindable != null && property != null) {
				bindable.SetBinding(property, binding);
				return true;
			}

			if (nativeBindingService != null && property != null && nativeBindingService.TrySetBinding(element, property, binding))
				return true;

			if (nativeBindingService != null && nativeBindingService.TrySetBinding(element, localName, binding))
				return true;

			if (property != null)
				exception = new XamlParseException($"{elementType.Name} is not a BindableObject or does not support native bindings", lineInfo);

			return false;
		}

		static bool TrySetValue(object element, BindableProperty property, bool attached, object value, IXmlLineInfo lineInfo, XamlServiceProvider serviceProvider, out Exception exception)
		{
			exception = null;

			var elementType = element.GetType();
			var bindable = element as BindableObject;
			var nativeBindingService = DependencyService.Get<INativeBindingService>();

			if (property == null)
				return false;

			if (serviceProvider != null && serviceProvider.IProvideValueTarget != null)
				((XamlValueTargetProvider)serviceProvider.IProvideValueTarget).TargetProperty = property;

			Func<MemberInfo> minforetriever;
			if (attached)
				minforetriever = () =>
				{
					try {
						return property.DeclaringType.GetRuntimeMethod("Get" + property.PropertyName, new[] { typeof(BindableObject) });
					} catch (AmbiguousMatchException e) {
						throw new XamlParseException($"Multiple methods with name '{property.DeclaringType}.Get{property.PropertyName}' found.", lineInfo, innerException: e);
					}
				};
			else
				minforetriever = () =>
				{
					try {
						return property.DeclaringType.GetRuntimeProperty(property.PropertyName);
					} catch (AmbiguousMatchException e) {
						throw new XamlParseException($"Multiple properties with name '{property.DeclaringType}.{property.PropertyName}' found.", lineInfo, innerException: e);
					}
				};
			var convertedValue = value.ConvertTo(property.ReturnType, minforetriever, serviceProvider, out exception);
			if (exception != null)
				return false;

			if (bindable != null) {
				//SetValue doesn't throw on mismatching type, so check before to get a chance to try the property setting or the collection adding
				var nullable = property.ReturnTypeInfo.IsGenericType &&
							   property.ReturnTypeInfo.GetGenericTypeDefinition() == typeof(Nullable<>);
				if ((convertedValue == null && (!property.ReturnTypeInfo.IsValueType || nullable)) ||
					(property.ReturnType.IsInstanceOfType(convertedValue))) {
					try {
						bindable.SetValue(property, convertedValue);
						return true;
					}
					catch (Exception e) {
						exception = e;
						return false;
					}
				}

				// This might be a collection; see if we can add to it
				return TryAddValue(bindable, property, value, serviceProvider, out exception);
			}

			if (nativeBindingService != null && nativeBindingService.TrySetValue(element, property, convertedValue))
				return true;

			exception = new XamlParseException($"{elementType.Name} is not a BindableObject or does not support setting native BindableProperties", lineInfo);
			return false;
		}

		static bool TryGetValue(object element, BindableProperty property, bool attached, out object value, IXmlLineInfo lineInfo, out Exception exception, out object targetProperty)
		{
			exception = null;
			value = null;
			targetProperty = property;
			var elementType = element.GetType();
			var bindable = element as BindableObject;

			if (property == null)
				return false;

			if (bindable == null)
				return false;

			value = bindable.GetValue(property);
			return true;
		}

		static bool TrySetProperty(object element, string localName, object value, IXmlLineInfo lineInfo, XamlServiceProvider serviceProvider, HydrationContext context, out Exception exception)
		{
			exception = null;

			var elementType = element.GetType();
			var propertyInfo = elementType.GetRuntimeProperties().FirstOrDefault(p => p.Name == localName);
			MethodInfo setter;
			if (propertyInfo == null || !propertyInfo.CanWrite || (setter = propertyInfo.SetMethod) == null)
				return false;

			if (!IsVisibleFrom(setter, context.RootElement))
				return false;

			if (serviceProvider != null && serviceProvider.IProvideValueTarget != null)
				((XamlValueTargetProvider)serviceProvider.IProvideValueTarget).TargetProperty = propertyInfo;

			object convertedValue = value.ConvertTo(propertyInfo.PropertyType, () => propertyInfo, serviceProvider, out exception);
			if (exception != null || (convertedValue != null && !propertyInfo.PropertyType.IsInstanceOfType(convertedValue)))
				return false;

			try {
				setter.Invoke(element, new object[] { convertedValue });
				return true;
			}
			catch (Exception e) {
				exception = e;
				return false;
			}
		}

		static bool TryGetProperty(object element, string localName, out object value, IXmlLineInfo lineInfo, HydrationContext context, out Exception exception, out object targetProperty)
		{
			exception = null;
			value = null;
			var elementType = element.GetType();
			PropertyInfo propertyInfo = null;
#if NETSTANDARD1_0
			try {
				propertyInfo = elementType.GetRuntimeProperty(localName);
			} catch (AmbiguousMatchException) {
				// Get most derived instance of property
				foreach (var property in elementType.GetRuntimeProperties().Where(prop => prop.Name == localName)) {
					if (propertyInfo == null || propertyInfo.DeclaringType.IsAssignableFrom(property.DeclaringType))
						propertyInfo = property;
				}
			}
#else
			while (elementType != null && propertyInfo == null) {
				try {
					propertyInfo = elementType.GetProperty(localName, BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly);
				} catch (AmbiguousMatchException e) {
					throw new XamlParseException($"Multiple properties with name '{elementType}.{localName}' found.", lineInfo, innerException: e);
				}
				elementType = elementType.BaseType;
			}
#endif
			MethodInfo getter;
			targetProperty = propertyInfo;
			if (propertyInfo == null || !propertyInfo.CanRead || (getter = propertyInfo.GetMethod) == null)
				return false;

			if (!IsVisibleFrom(getter, context.RootElement))
				return false;

			value = getter.Invoke(element, new object[] { });
			return true;
		}

		static bool IsVisibleFrom(MethodInfo method, object rootElement)
		{
			if (method.IsPublic)
				return true;
			if (method.IsPrivate && method.DeclaringType == rootElement.GetType())
				return true;
			if ((method.IsAssembly || method.IsFamilyOrAssembly) && method.DeclaringType.AssemblyQualifiedName == rootElement.GetType().AssemblyQualifiedName)
				return true;
			if (method.IsFamily && method.DeclaringType.IsAssignableFrom(rootElement.GetType()))
				return true;
			return false;
		}

		static bool TryAddToProperty(object element, XmlName propertyName, object value, string xKey, IXmlLineInfo lineInfo, XamlServiceProvider serviceProvider, HydrationContext context, out Exception exception)
		{
			exception = null;
			if (!(GetPropertyValue(element, propertyName, context, lineInfo, out _, out var targetProperty) is IEnumerable collection))
				return false;

			if (exception == null && TryAddToResourceDictionary(collection as ResourceDictionary, value, xKey, lineInfo, out exception))
				return true;

			if (exception != null)
				return false;

			var addMethod = collection.GetType().GetRuntimeMethods().First(mi => mi.Name == "Add" && mi.GetParameters().Length == 1);
			if (addMethod == null)
				return false;

			if (serviceProvider != null)
				((XamlValueTargetProvider)serviceProvider.IProvideValueTarget).TargetProperty = targetProperty;

			try {
				addMethod.Invoke(collection, new[] { value.ConvertTo(addMethod.GetParameters()[0].ParameterType, (Func<TypeConverter>)null, serviceProvider, out exception) });
			}
			catch (Exception e) {
				exception = e;
			}
			return exception == null;
		}

		static bool TryAddToResourceDictionary(ResourceDictionary resourceDictionary, object value, string xKey, IXmlLineInfo lineInfo, out Exception exception)
		{
			exception = null;

			if (resourceDictionary == null)
				return false;

			if (xKey != null)
				resourceDictionary.Add(xKey, value);
			else if (value is Style)
				resourceDictionary.Add((Style)value);
			else if (value is ResourceDictionary)
				resourceDictionary.Add((ResourceDictionary)value);
			else if (value is StyleSheets.StyleSheet)
				resourceDictionary.Add((StyleSheets.StyleSheet)value);
			else {
				exception = new XamlParseException("resources in ResourceDictionary require a x:Key attribute", lineInfo);
				return false;
			}
			return true;
		}

		void SetTemplate(ElementTemplate dt, INode node)
		{
#pragma warning disable 0612
			((IDataTemplate)dt).LoadTemplate = () => {
#pragma warning restore 0612
				var cnode = node.Clone();
				var context = new HydrationContext { ParentContext = Context, RootAssembly = Context.RootAssembly, RootElement = Context.RootElement, ExceptionHandler = Context.ExceptionHandler };
				cnode.Accept(new XamlNodeVisitor((n, parent) => n.Parent = parent), node.Parent); //set parents for {StaticResource}
				cnode.Accept(new ExpandMarkupsVisitor(context), null);
				cnode.Accept(new NamescopingVisitor(context), null);
				cnode.Accept(new CreateValuesVisitor(context), null);
				cnode.Accept(new RegisterXNamesVisitor(context), null);
				cnode.Accept(new FillResourceDictionariesVisitor(context), null);
				cnode.Accept(new ApplyPropertiesVisitor(context, true), null);
				return context.Values [cnode];
			};
		}

		static bool TryAddValue(BindableObject bindable, BindableProperty property, object value, XamlServiceProvider serviceProvider, out Exception exception)
		{
			exception = null;

			if (property?.ReturnTypeInfo?.GenericTypeArguments == null)
				return false;

			if (property.ReturnType == null)
				return false;

			if (property.ReturnTypeInfo.GenericTypeArguments.Length != 1 || !property.ReturnTypeInfo.GenericTypeArguments[0].IsInstanceOfType(value))
				return false;

			// This might be a collection we can add to; see if we can find an Add method
			var addMethod = GetAllRuntimeMethods(property.ReturnType).FirstOrDefault(mi => mi.Name == "Add" && mi.GetParameters().Length == 1);
			if (addMethod == null)
				return false;

			// If there's an add method, get the collection
			var collection = bindable.GetValue(property);
			
			// And add the new value to it
			addMethod.Invoke(collection, new[] { value.ConvertTo(addMethod.GetParameters()[0].ParameterType, (Func<TypeConverter>)null, serviceProvider, out exception) });
			return exception == null;
		}

		static IEnumerable<MethodInfo> GetAllRuntimeMethods(Type type)
		{
			return type.GetRuntimeMethods()
				.Concat(type.GetTypeInfo().ImplementedInterfaces.SelectMany(t => t.GetRuntimeMethods()));
		}

		bool TrySetRuntimeName(XmlName propertyName, object source, object value, ValueNode node)
		{
			if (propertyName != XmlName.xName)
				return false;

			var runTimeName = source.GetType().GetTypeInfo().GetCustomAttribute<RuntimeNamePropertyAttribute>();
			if (runTimeName == null)
				return false;

			SetPropertyValue(source, new XmlName("", runTimeName.Name), value, Context.RootElement, node, Context, node);
			return true;
		}
	}
}