Merge pull request #2374 from FirelyTeam/feature/2373-support-for-sin…

…ce-on-choice-element

2373 Added support elements that have changed from choice to non-choice.

src/Hl7.Fhir.Base/Introspection/PropertyMapping.cs

@@ -215,10 +215,10 @@ public static bool TryCreate(PropertyInfo prop, out PropertyMapping? result, Cla
                 throw new InvalidOperationException($"Property {prop.Name} in class {prop.DeclaringType!.Name} is of type " +
                     $"{fhirType}, for which a classmapping cannot be found.");
 
-            // The [AllowedElements] attribute can specify a set of allowed types
-            // for this element. Take this list as the declared list of FHIR types.
-            // If not present assume this is the implementing FHIR type above
-            var allowedTypes = ClassMapping.GetAttribute<AllowedTypesAttribute>(prop, release);
+            // The [AllowedElements] attribute can specify a set of allowed types for this element.
+            // If this is a choice element, then take this list as the declared list of FHIR types,
+            // otherwise assume this is the implementing FHIR type above
+            var allowedTypes = elementAttr.Choice != ChoiceType.None ? ClassMapping.GetAttribute<AllowedTypesAttribute>(prop, release) : null;
 
             var fhirTypes = allowedTypes?.Types?.Any() == true ?
                 allowedTypes.Types : new[] { fhirType };
@@ -243,6 +243,23 @@ public static bool TryCreate(PropertyInfo prop, out PropertyMapping? result, Cla
             return true;
         }
 
+        /// <summary>
+        /// This function tried to figure out a concrete type for the element represented by this property.
+        /// If it cannot derive a concrete type, it will just return <see cref="ImplementingType"/>.
+        /// </summary>
+        internal Type GetInstantiableType()
+        {
+            if (!ImplementingType.IsAbstract)
+                return ImplementingType;
+
+            // Ok, so we're in abstract type land, maybe FhirType can help us
+            if (FhirType.Length == 1)
+                return FhirType[0];
+
+            // No, just return ImplementingType then.
+            return ImplementingType;
+        }
+
         private static bool isPrimitiveValueElement(FhirElementAttribute valueElementAttr, PropertyInfo prop)
         {
             var isValueElement = valueElementAttr != null && valueElementAttr.IsPrimitiveValue;

src/Hl7.Fhir.Base/Introspection/ReferencesAttribute.cs

@@ -33,7 +33,7 @@ POSSIBILITY OF SUCH DAMAGE.
 namespace Hl7.Fhir.Introspection
 {
     [CLSCompliant(false)]
-    [AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]
+    [AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = true)]
     public class ReferencesAttribute : VersionedAttribute
     {
         public ReferencesAttribute(params string[] resources)

src/Hl7.Fhir.Base/Model/Generated/Signature.cs

@@ -103,32 +103,40 @@ public DateTimeOffset? When
     /// <summary>
     /// Who signed. Note: Since R5 the cardinality is expanded to 0..1 (previous it was 1..1)
     /// </summary>
-    [FhirElement("who", InSummary=true, Order=50)]
+    [FhirElement("who", InSummary = true, Order = 50, Choice = ChoiceType.DatatypeChoice)]
+    [FhirElement("who", InSummary = true, Order = 50, Since = FhirRelease.R4)]
     [CLSCompliant(false)]
-    [References("Practitioner","PractitionerRole","RelatedPerson","Patient","Device","Organization")]
-    [DataMember]
-    public Hl7.Fhir.Model.ResourceReference Who
+    [References("Practitioner", "RelatedPerson", "Patient", "Device", "Organization")]
+    [References("Practitioner", "PractitionerRole", "RelatedPerson", "Patient", "Device", "Organization",Since=FhirRelease.R4)]
+    [AllowedTypes(typeof(Hl7.Fhir.Model.FhirUri), typeof(Hl7.Fhir.Model.ResourceReference))]
+    [DeclaredType(Type = typeof(ResourceReference), Since=FhirRelease.R4)]
+    [DataMember]      
+    public Hl7.Fhir.Model.DataType Who
     {
       get { return _Who; }
       set { _Who = value; OnPropertyChanged("Who"); }
     }
 
-    private Hl7.Fhir.Model.ResourceReference _Who;
+    private Hl7.Fhir.Model.DataType _Who;
 
     /// <summary>
     /// The party represented
     /// </summary>
-    [FhirElement("onBehalfOf", InSummary=true, Order=60)]
+    [FhirElement("onBehalfOf", InSummary = true, Order = 60, Choice = ChoiceType.DatatypeChoice)]
+    [FhirElement("onBehalfOf", InSummary=true, Order=60, Since = FhirRelease.R4)]        
     [CLSCompliant(false)]
-    [References("Practitioner","PractitionerRole","RelatedPerson","Patient","Device","Organization")]
+    [References("Practitioner", "RelatedPerson", "Patient", "Device", "Organization")]
+    [References("Practitioner","PractitionerRole","RelatedPerson","Patient","Device","Organization",Since=FhirRelease.R4)]
+    [AllowedTypes(typeof(Hl7.Fhir.Model.FhirUri), typeof(Hl7.Fhir.Model.ResourceReference))]
+    [DeclaredType(Type = typeof(ResourceReference), Since = FhirRelease.R4)]
     [DataMember]
-    public Hl7.Fhir.Model.ResourceReference OnBehalfOf
+    public Hl7.Fhir.Model.DataType OnBehalfOf
     {
       get { return _OnBehalfOf; }
       set { _OnBehalfOf = value; OnPropertyChanged("OnBehalfOf"); }
     }
 
-    private Hl7.Fhir.Model.ResourceReference _OnBehalfOf;
+    private Hl7.Fhir.Model.DataType _OnBehalfOf;
 
     /// <summary>
     /// The technical format of the signed resources

src/Hl7.Fhir.Base/Serialization/BaseFhirJsonPocoDeserializer.cs

@@ -15,6 +15,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Text;
 using System.Text.Json;
 using ERR = Hl7.Fhir.Serialization.FhirJsonException;
 
@@ -99,6 +100,18 @@ public Resource DeserializeResource(ref Utf8JsonReader reader)
                 : throw new DeserializationFailedException(result, state.Errors);
         }
 
+        /// <summary>
+        /// Deserialize the FHIR Json from the reader and create a new POCO object containing the data from the reader.
+        /// </summary>
+        /// <param name="json">A string of json.</param>
+        /// <returns>A fully initialized POCO with the data from the reader.</returns>
+        public Resource DeserializeResource(string json)
+        {
+            var reader = new Utf8JsonReader(Encoding.UTF8.GetBytes(json), new() { CommentHandling = JsonCommentHandling.Skip });
+
+            return DeserializeResource(ref reader);
+        }
+
         /// <summary>
         /// Reads a (subtree) of serialized FHIR Json data into a POCO object.
         /// </summary>
@@ -882,7 +895,7 @@ private static (PropertyMapping? propMapping, ClassMapping? propValueMapping, Fh
             (ClassMapping? propertyValueMapping, FhirJsonException? error) = propertyMapping.Choice switch
             {
                 ChoiceType.None or ChoiceType.ResourceChoice =>
-                    inspector.FindOrImportClassMapping(propertyMapping.ImplementingType) is ClassMapping m
+                    inspector.FindOrImportClassMapping(propertyMapping.GetInstantiableType()) is ClassMapping m
                         ? (m, null)
                         : throw new InvalidOperationException($"Encountered property type {propertyMapping.ImplementingType} for which no mapping was found in the model assemblies. " + reader.GenerateLocationMessage()),
                 ChoiceType.DatatypeChoice => getChoiceClassMapping(ref reader),

src/Hl7.Fhir.Base/Serialization/BaseFhirJsonPocoSerializer.cs

@@ -17,7 +17,10 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Runtime.InteropServices.ComTypes;
+using System.Text;
 using System.Text.Json;
 
 namespace Hl7.Fhir.Serialization
@@ -63,6 +66,18 @@ public BaseFhirJsonPocoSerializer(FhirRelease release, FhirJsonPocoSerializerSet
         public void Serialize(IReadOnlyDictionary<string, object> members, Utf8JsonWriter writer) =>
             serializeInternal(members, writer, skipValue: false);
 
+        /// <summary>
+        /// Serializes the given dictionary with FHIR data into a Json string.
+        /// </summary>
+        public string SerializeToString(IReadOnlyDictionary<string, object> members)
+        {
+            var stream = new MemoryStream();
+            var writer = new Utf8JsonWriter(stream);
+            serializeInternal(members, writer, skipValue: false);
+            writer.Flush();
+            return Encoding.UTF8.GetString(stream.ToArray());
+        }
+
         /// <summary>
         /// Serializes the given dictionary with FHIR data into Json, optionally skipping the "value" element.
         /// </summary>

src/Hl7.Fhir.Base/Serialization/BaseFhirXmlPocoDeserializer.cs

@@ -650,7 +650,7 @@ private static (PropertyMapping? propMapping, ClassMapping? propValueMapping, Fh
             (ClassMapping? propertyValueMapping, FhirXmlException? error) = propertyMapping.Choice switch
             {
                 ChoiceType.None or ChoiceType.ResourceChoice =>
-                    inspector.FindOrImportClassMapping(propertyMapping.ImplementingType) is ClassMapping m
+                    inspector.FindOrImportClassMapping(propertyMapping.GetInstantiableType()) is ClassMapping m
                         ? (m, null)
                         : throw new InvalidOperationException($"Encountered property type {propertyMapping.ImplementingType} for which no mapping was found in the model assemblies. " + reader.GenerateLocationMessage()),
                 ChoiceType.DatatypeChoice => getChoiceClassMapping(reader),

src/Hl7.Fhir.Base/Serialization/DispatchingReader.cs

@@ -10,7 +10,9 @@
 using Hl7.Fhir.Introspection;
 using Hl7.Fhir.Model;
 using Hl7.Fhir.Utility;
+using System;
 using System.Collections;
+using System.Linq;
 
 namespace Hl7.Fhir.Serialization
 {
@@ -70,7 +72,7 @@ public object Deserialize(PropertyMapping prop, string memberName, object existi
 
             ClassMapping mapping = prop.Choice == ChoiceType.DatatypeChoice
                 ? getMappingForType(memberName, _current.InstanceType)
-                : _inspector.FindOrImportClassMapping(prop.ImplementingType);
+                : _inspector.FindOrImportClassMapping(prop.GetInstantiableType());
 
             // Handle other Choices having any datatype or a list of datatypes
 

src/Hl7.Fhir.Serialization.R4.Tests/RoundtripSignature.cs

@@ -0,0 +1,83 @@
+using FluentAssertions;
+using Hl7.Fhir.ElementModel;
+using Hl7.Fhir.Model;
+using Hl7.Fhir.Specification;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Linq;
+
+namespace Hl7.Fhir.Serialization.Tests
+{
+    // Signature is special, since it's the first case where
+    // an element changed from a choice element in STU3 to a non-choice element in R4.
+    // These unit-tests will exercise those parts that are sensitive to such a change.
+    [TestClass]
+    public class RoundtripSignature
+    {
+        [TestMethod]
+        public void ModelInfoHasCorrectInfo()
+        {
+            var cls = ModelInfo.ModelInspector.FindClassMapping("Signature");
+            cls.FindMappedElementByChoiceName("whoReference").Should().BeNull();
+            var prop = cls.FindMappedElementByName("who");
+            prop.Should().NotBeNull();
+
+            prop.Choice.Should().Be(Introspection.ChoiceType.None);
+            prop.ImplementingType.Should().Be(typeof(DataType));
+            prop.PropertyTypeMapping.Name.Should().Be("Reference");
+            prop.FhirType.Should().BeEquivalentTo(new[] { typeof(ResourceReference) });
+        }
+
+        [TestMethod]
+        public void SDSHasCorrectInfo()
+        {
+            var cls = new PocoStructureDefinitionSummaryProvider().Provide(ModelInfo.CanonicalUriForFhirCoreType("Signature"));
+            var elem = cls.GetElements().Single(e => e.ElementName == "who");
+            cls.GetElements().Where(e => e.ElementName == "whoReference").Should().BeEmpty();
+            validateEDS(elem);
+        }
+
+        private void validateEDS(IElementDefinitionSummary eds)
+        {
+            eds.IsChoiceElement.Should().BeFalse();
+            eds.Type.Select(t => t.GetTypeName()).Should().BeEquivalentTo("Reference");
+        }
+
+        [TestMethod]
+        public void TypedElementHasCorrectInfo()
+        {
+            var cls = new Signature() { Who = new ResourceReference("http://nu.nl") }.ToTypedElement();
+
+            var who = cls.Children("who").Single();
+            who.Name.Should().Be("who");
+            who.InstanceType.Should().Be("Reference");
+            validateEDS(who.Definition);
+        }
+
+        [TestMethod]
+        public void WorksWithTypedElementSerializers()
+        {
+            var sig = new Bundle() { Signature = new Signature() { Who = new ResourceReference("http://nu.nl") } };
+            var json =  sig.ToTypedElement().ToJson();
+            json.Should().Contain("\"who\"");
+            var sig2 = FhirJsonNode.Parse(json).ToPoco();
+            sig.IsExactly(sig2).Should().BeTrue();
+        }
+
+        [TestMethod]
+        public void WorksWithPocoSerializers()
+        {
+            var sig = new Bundle() { Type = Bundle.BundleType.Document, Signature = new Signature() { Who = new ResourceReference("http://nu.nl") } };
+            var json = new FhirJsonPocoSerializer().SerializeToString(sig);
+            json.Should().Contain("\"who\"");
+            var sig2 = new FhirJsonPocoDeserializer().DeserializeResource(json);
+            sig.IsExactly(sig2).Should().BeTrue();
+
+            var xml = new FhirXmlPocoSerializer().SerializeToString(sig);
+            xml.Should().Contain("<who>");
+            var sig3 = new FhirXmlPocoDeserializer().DeserializeResource(xml);
+            sig.IsExactly(sig3).Should().BeTrue();
+
+        }
+    }
+}

src/Hl7.Fhir.Serialization.STU3.Tests/RoundtripSignature.cs

@@ -0,0 +1,82 @@
+using FluentAssertions;
+using Hl7.Fhir.ElementModel;
+using Hl7.Fhir.Model;
+using Hl7.Fhir.Specification;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Linq;
+
+namespace Hl7.Fhir.Serialization.Tests
+{
+    // Signature is special, since it's the first case where
+    // an element changed from a choice element in STU3 to a non-choice element in R4.
+    // These unit-tests will exercise those parts that are sensitive to such a change.
+    [TestClass]
+    public class RoundtripSignature
+    {
+        [TestMethod]
+        public void ModelInfoHasCorrectInfo()
+        {
+            var cls = ModelInfo.ModelInspector.FindClassMapping("Signature");
+            cls.FindMappedElementByName("who").Should().NotBeNull();
+            var prop = cls.FindMappedElementByChoiceName("whoReference");
+            prop.Should().NotBeNull();
+
+            prop.Choice.Should().Be(Introspection.ChoiceType.DatatypeChoice);
+            prop.ImplementingType.Should().Be(typeof(DataType));
+            prop.PropertyTypeMapping.Name.Should().Be("DataType");
+            prop.FhirType.Should().BeEquivalentTo(new Type[] { typeof(FhirUri), typeof(ResourceReference) });
+        }
+
+        [TestMethod]
+        public void SDSHasCorrectInfo()
+        {
+            var cls = new PocoStructureDefinitionSummaryProvider().Provide("http://hl7.org/fhir/StructureDefinition/Signature");
+            var elem = cls.GetElements().Single(e => e.ElementName == "who");
+            cls.GetElements().Where(e => e.ElementName == "whoReference").Should().BeEmpty();
+            validateEDS(elem);
+        }
+
+        private void validateEDS(IElementDefinitionSummary eds)
+        {
+            eds.IsChoiceElement.Should().BeTrue();
+            eds.Type.Select(t => t.GetTypeName()).Should().BeEquivalentTo("uri", "Reference");
+        }
+
+        [TestMethod]
+        public void TypedElementHasCorrectInfo()
+        {
+            var cls = new Signature() { Who = new ResourceReference("http://nu.nl") }.ToTypedElement();
+
+            var who = cls.Children("who").Single();
+            who.Name.Should().Be("who");
+            who.InstanceType.Should().Be("Reference");
+            validateEDS(who.Definition);
+        }
+
+        [TestMethod]
+        public void WorksWithTypedElementSerializers()
+        {
+            var sig = new Bundle() { Signature = new Signature() { Who = new ResourceReference("http://nu.nl") } };
+            var json = sig.ToTypedElement().ToJson();
+            json.Should().Contain("\"whoReference\"");
+            var sig2 = FhirJsonNode.Parse(json).ToPoco();
+            sig.IsExactly(sig2).Should().BeTrue();
+        }
+
+        [TestMethod]
+        public void WorksWithPocoSerializers()
+        {
+            var sig = new Bundle() { Type = Bundle.BundleType.Document, Signature = new Signature() { Who = new ResourceReference("http://nu.nl") } };
+            var json = new FhirJsonPocoSerializer().SerializeToString(sig);
+            json.Should().Contain("\"whoReference\"");
+            var sig2 = new FhirJsonPocoDeserializer().DeserializeResource(json);
+            sig.IsExactly(sig2).Should().BeTrue();
+
+            var xml = new FhirXmlPocoSerializer().SerializeToString(sig);
+            xml.Should().Contain("<whoReference>");
+            var sig3 = new FhirXmlPocoDeserializer().DeserializeResource(xml);
+            sig.IsExactly(sig3).Should().BeTrue();
+        }
+    }
+}