Rewrite of use of UmbracoContext & ApplicationContext (See description)

Based on the idea of https://github.com/umbraco/Umbraco-CMS/blob/release-7.3.2/src/Umbraco.Web/IUmbracoContextAccessor.cs & https://github.com/umbraco/Umbraco-CMS/blob/release-7.3.2/src/Umbraco.Web/SingletonUmbracoContextAccessor.cs

I've implemented an "UmbracoApplicationContextAccessor which allows readonly access to the UmbracoContext & ApplicationContext. In most cases this will use the SingletonUmbracoApplicationContextAccessor but in the case of tests there is a publicly available static register method to setup an alternative which used a mocked version of this accessor.

Not happy about the accessor being passed through so many properties but it's the best way I can think of to ensure we're using exactly the same contexts from method to method.

src/Our.Umbraco.Ditto/Common/UmbracoApplicationContextAccessor.cs

@@ -0,0 +1,40 @@
+using Umbraco.Core;
+using Umbraco.Web;
+
+namespace Our.Umbraco.Ditto
+{
+    /// <summary>
+    /// An interface allowing access to the UmbracoContext &amp; ApplicationContext without resulting to using the singletons directly.
+    /// </summary>
+    public interface IUmbracoApplicationContextAccessor
+    {
+        /// <summary>
+        /// The UmbracoContext instance.
+        /// </summary>
+        UmbracoContext UmbracoContext { get; }
+
+        /// <summary>
+        /// The ApplicationContext instance.
+        /// </summary>
+        ApplicationContext ApplicationContext { get; }
+    }
+
+    internal class SingletonUmbracoApplicationContextAccessor : IUmbracoApplicationContextAccessor
+    {
+        public UmbracoContext UmbracoContext
+        {
+            get
+            {
+                return UmbracoContext.Current;
+            }
+        }
+
+        public ApplicationContext ApplicationContext
+        {
+            get
+            {
+                return ApplicationContext.Current;
+            }
+        }
+    }
+}

src/Our.Umbraco.Ditto/ComponentModel/Attributes/DittoMultiProcessorAttribute.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace Our.Umbraco.Ditto
 {

src/Our.Umbraco.Ditto/ComponentModel/Attributes/DittoProcessorAttribute.cs

@@ -18,31 +18,13 @@ public abstract class DittoProcessorAttribute : DittoCacheableAttribute
         /// <summary>
         /// Initializes a new instance of the <see cref="DittoProcessorAttribute"/> class.
         /// </summary>
-        protected DittoProcessorAttribute() : this(UmbracoContext.Current, ApplicationContext.Current) { }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="DittoProcessorAttribute"/> class.
-        /// </summary>
-        /// <param name="umbracoContext"></param>
-        /// <param name="applicationContext"></param>
-        protected DittoProcessorAttribute(UmbracoContext umbracoContext, ApplicationContext applicationContext)
+        protected DittoProcessorAttribute()
         {
-            if (umbracoContext == null)
-            {
-                throw new ArgumentNullException("umbracoContext");
-            }
-
-            if (applicationContext == null)
-            {
-                throw new ArgumentNullException("applicationContext");
-            }
             var metaData = this.GetType().GetCustomAttribute<DittoProcessorMetaDataAttribute>(true);
             if (metaData == null)
             {
                 throw new ApplicationException("Ditto processor attributes require a DittoProcessorMetaData attribute to be applied to the class but none was found");
             }
-            this.Umbraco = umbracoContext;
-            this.ApplicationContext = applicationContext;
 
             this.ValueType = metaData.ValueType;
             this.ContextType = metaData.ContextType;
@@ -115,12 +97,12 @@ protected virtual ProfilingLogger ProfilingLogger
         /// <summary>
         /// Returns the current UmbracoContext
         /// </summary>
-        protected virtual UmbracoContext Umbraco { get; private set; }
+        public virtual UmbracoContext Umbraco { get; internal set; }
 
         /// <summary>
         /// Returns the current ApplicationContext
         /// </summary>
-        protected virtual ApplicationContext ApplicationContext { get; private set; }
+        public virtual ApplicationContext ApplicationContext { get; internal set; }
 
         /// <summary>
         /// Returns a ServiceContext
@@ -155,7 +137,7 @@ protected DatabaseContext DatabaseContext
         /// The <see cref="object" /> representing the processed value.
         /// </returns>
         internal virtual object ProcessValue(
-            object value, 
+            object value,
             DittoProcessorContext context)
         {
             if (value != null && !this.ValueType.IsInstanceOfType(value))

src/Our.Umbraco.Ditto/ComponentModel/Processors/DittoProcessorRegistry.cs

@@ -30,6 +30,11 @@ internal class DittoProcessorRegistry
         /// </summary>
         private Type defaultProcessorType = typeof(UmbracoPropertyAttribute);
 
+        /// <summary>
+        /// The default umbraco application context accessor type for processors, (defaults to `SingletonUmbracoApplicationContextAccessor`).
+        /// </summary>
+        private Type defaultUmbracoApplicationContextAccessorType = typeof(SingletonUmbracoApplicationContextAccessor);
+
         /// <summary>
         /// Prevents a default instance of the <see cref="DittoProcessorRegistry"/> class from being created.
         /// </summary>
@@ -143,5 +148,26 @@ public IEnumerable<DittoProcessorAttribute> GetRegisteredProcessorAttributesFor(
                     : Enumerable.Empty<DittoProcessorAttribute>();
             }
         }
+
+        /// <summary>
+        /// Registers the default umbraco application context accessor type.
+        /// </summary>
+        /// <typeparam name="TUmbracoApplicationContextAccessorType">The umbraco application context accessor type.</typeparam>
+        public void RegisterDefaultUmbracoApplicationContextAccessorType<TUmbracoApplicationContextAccessorType>()
+            where TUmbracoApplicationContextAccessorType : IUmbracoApplicationContextAccessor, new()
+        {
+            this.defaultUmbracoApplicationContextAccessorType = typeof(TUmbracoApplicationContextAccessorType);
+        }
+
+        /// <summary>
+        /// Gets the default umbraco application context accessor type.
+        /// </summary>
+        /// <returns>
+        /// Returns the default umbraco application context accessor type.
+        /// </returns>
+        public Type GetDefaultUmbracoApplicationContextAccessorType()
+        {
+            return this.defaultUmbracoApplicationContextAccessorType;
+        }
     }
 }

src/Our.Umbraco.Ditto/Ditto.cs

@@ -135,5 +135,15 @@ public static void RegisterDefaultProcessorType<TProcessorAttributeType>()
         {
             TypeDescriptor.AddAttributes(typeof(TObjectType), new TypeConverterAttribute(typeof(TConverterType)));
         }
+
+        /// <summary>
+        /// Registers a global umbraco application context accessor.
+        /// </summary>
+        /// <typeparam name="TUmbracoApplicationContextAccessorType">The type of the accessor.</typeparam>
+        public static void RegisterUmbracoApplicationContextAccessor<TUmbracoApplicationContextAccessorType>()
+            where TUmbracoApplicationContextAccessorType : IUmbracoApplicationContextAccessor, new()
+        {
+            DittoProcessorRegistry.Instance.RegisterDefaultUmbracoApplicationContextAccessorType<TUmbracoApplicationContextAccessorType>();
+        }
     }
 }

src/Our.Umbraco.Ditto/Extensions/PublishedContentExtensions.cs

@@ -11,6 +11,7 @@
 
 namespace Our.Umbraco.Ditto
 {
+    using global::Umbraco.Core;
     using System.Collections;
 
     /// <summary>
@@ -192,12 +193,15 @@ public static class PublishedContentExtensions
                 throw new ArgumentException(string.Format("The instance parameter does not implement Type '{0}'", type.Name), "instance");
             }
 
+            // Get the accessor for UmbracoContext & ApplicationContext
+            var defaultUmbracoApplicationContextAccessor = (IUmbracoApplicationContextAccessor)Activator.CreateInstance(DittoProcessorRegistry.Instance.GetDefaultUmbracoApplicationContextAccessorType());
+
             // Check if the culture has been set, otherwise use from Umbraco, or fallback to a default
             if (culture == null)
             {
-                if (UmbracoContext.Current != null && UmbracoContext.Current.PublishedContentRequest != null)
+                if (defaultUmbracoApplicationContextAccessor.UmbracoContext != null && defaultUmbracoApplicationContextAccessor.UmbracoContext.PublishedContentRequest != null)
                 {
-                    culture = UmbracoContext.Current.PublishedContentRequest.Culture;
+                    culture = defaultUmbracoApplicationContextAccessor.UmbracoContext.PublishedContentRequest.Culture;
                 }
                 else
                 {
@@ -213,11 +217,11 @@ public static class PublishedContentExtensions
                 if (cacheAttr != null)
                 {
                     var ctx = new DittoCacheContext(cacheAttr, content, type, culture);
-                    return cacheAttr.GetCacheItem(ctx, () => ConvertContent(content, type, culture, instance, processorContexts, onConverting, onConverted));
+                    return cacheAttr.GetCacheItem(ctx, () => ConvertContent(content, type, defaultUmbracoApplicationContextAccessor, culture, instance, processorContexts, onConverting, onConverted));
                 }
                 else
                 {
-                    return ConvertContent(content, type, culture, instance, processorContexts, onConverting, onConverted);
+                    return ConvertContent(content, type, defaultUmbracoApplicationContextAccessor, culture, instance, processorContexts, onConverting, onConverted);
                 }
             }
         }
@@ -231,6 +235,9 @@ public static class PublishedContentExtensions
         /// <param name="type">
         /// The <see cref="Type"/> of items to return.
         /// </param>
+        /// <param name="umbracoApplicationContextAccessor">
+        /// The umbraco application context accessor.
+        /// </param>
         /// <param name="culture">
         /// The <see cref="CultureInfo"/>
         /// </param>
@@ -255,6 +262,7 @@ public static class PublishedContentExtensions
         private static object ConvertContent(
             IPublishedContent content,
             Type type,
+            IUmbracoApplicationContextAccessor umbracoApplicationContextAccessor,
             CultureInfo culture = null,
             object instance = null,
             IEnumerable<DittoProcessorContext> processorContexts = null,
@@ -334,7 +342,7 @@ public static class PublishedContentExtensions
                     var localInstance = instance;
 
                     // ReSharper disable once PossibleMultipleEnumeration
-                    lazyProperties.Add(propertyInfo.Name, new Lazy<object>(() => GetProcessedValue(content, culture, type, deferredPropertyInfo, localInstance, defaultProcessorType, processorContexts)));
+                    lazyProperties.Add(propertyInfo.Name, new Lazy<object>(() => GetProcessedValue(content, culture, type, deferredPropertyInfo, localInstance, defaultProcessorType, umbracoApplicationContextAccessor, processorContexts)));
                 }
             }
 
@@ -367,7 +375,7 @@ public static class PublishedContentExtensions
 
                     // Set the value normally.
                     // ReSharper disable once PossibleMultipleEnumeration
-                    var value = GetProcessedValue(content, culture, type, propertyInfo, instance, defaultProcessorType, processorContexts);
+                    var value = GetProcessedValue(content, culture, type, propertyInfo, instance, defaultProcessorType, umbracoApplicationContextAccessor, processorContexts);
 
                     // This is 2x as fast as propertyInfo.SetValue(instance, value, null);
                     PropertyInfoInvocations.SetValue(propertyInfo, instance, value);
@@ -390,6 +398,7 @@ public static class PublishedContentExtensions
         /// <param name="propertyInfo">The <see cref="PropertyInfo" /> property info associated with the type.</param>
         /// <param name="instance">The instance to assign the value to.</param>
         /// <param name="defaultProcessorType">The default processor type.</param>
+        /// <param name="umbracoApplicationContextAccessor">The umbraco application context accessor.</param>
         /// <param name="processorContexts">A collection of <see cref="DittoProcessorContext" /> entities to use whilst processing values.</param>
         /// <returns>
         /// The <see cref="object" /> representing the Umbraco value.
@@ -401,6 +410,7 @@ public static class PublishedContentExtensions
             PropertyInfo propertyInfo,
             object instance,
             Type defaultProcessorType,
+            IUmbracoApplicationContextAccessor umbracoApplicationContextAccessor,
             IEnumerable<DittoProcessorContext> processorContexts = null)
         {
             // Time custom value-processor.
@@ -414,11 +424,11 @@ public static class PublishedContentExtensions
                 if (cacheAttr != null)
                 {
                     var ctx = new DittoCacheContext(cacheAttr, content, targetType, propertyDescriptor, culture);
-                    return cacheAttr.GetCacheItem(ctx, () => DoGetProcessedValue(content, culture, targetType, propertyInfo, propertyDescriptor, defaultProcessorType, processorContexts));
+                    return cacheAttr.GetCacheItem(ctx, () => DoGetProcessedValue(content, culture, targetType, propertyInfo, propertyDescriptor, defaultProcessorType, umbracoApplicationContextAccessor, processorContexts));
                 }
                 else
                 {
-                    return DoGetProcessedValue(content, culture, targetType, propertyInfo, propertyDescriptor, defaultProcessorType, processorContexts);
+                    return DoGetProcessedValue(content, culture, targetType, propertyInfo, propertyDescriptor, defaultProcessorType, umbracoApplicationContextAccessor, processorContexts);
                 }
             }
         }
@@ -432,6 +442,7 @@ public static class PublishedContentExtensions
         /// <param name="propertyInfo">The property information.</param>
         /// <param name="propertyDescriptor">The property descriptor.</param>
         /// <param name="defaultProcessorType">The default processor type.</param>
+        /// <param name="umbracoApplicationContextAccessor">The umbraco application context accessor.</param>
         /// <param name="processorContexts">The processor contexts.</param>
         /// <returns>Returns the processed value.</returns>
         private static object DoGetProcessedValue(
@@ -441,6 +452,7 @@ public static class PublishedContentExtensions
             PropertyInfo propertyInfo,
             PropertyDescriptor propertyDescriptor,
             Type defaultProcessorType,
+            IUmbracoApplicationContextAccessor umbracoApplicationContextAccessor,
             IEnumerable<DittoProcessorContext> processorContexts = null)
         {
             // Check the property for any explicit processor attributes
@@ -492,13 +504,17 @@ public static class PublishedContentExtensions
 
             // Add the passed in contexts
             processorContextsCache.AddContexts(processorContexts);
-
+            
             // Process attributes
             foreach (var processorAttr in processorAttrs)
             {
                 // Get the right context type
                 var ctx = processorContextsCache.GetOrCreateContext(processorAttr.ContextType);
 
+                // Populate UmbracoContext & ApplicationContext
+                processorAttr.Umbraco = umbracoApplicationContextAccessor.UmbracoContext;
+                processorAttr.ApplicationContext = umbracoApplicationContextAccessor.ApplicationContext;
+
                 // Process value
                 currentValue = processorAttr.ProcessValue(currentValue, ctx);
             }

src/Our.Umbraco.Ditto/Our.Umbraco.Ditto.csproj

@@ -76,6 +76,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Common\CachedInvocations.cs" />
+    <Compile Include="Common\UmbracoApplicationContextAccessor.cs" />
     <Compile Include="Common\PropertyInfoInvocations.cs" />
     <Compile Include="ComponentModel\Attributes\DittoDefaultProcessorAttribute.cs" />
     <Compile Include="ComponentModel\Attributes\DittoLazyAttribute.cs" />