Attribute validation error message now provides valid FHIR definitional paths.

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

@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
+using System.Reflection;
 
 #nullable enable
 
@@ -125,7 +126,18 @@ public FhirElementAttribute(string name, ChoiceType choice, XmlRepresentation re
 
         private void validateElement(object value, ValidationContext validationContext, List<ValidationResult> result)
         {
-            DotNetAttributeValidation.TryValidate(value, validationContext.IntoPath(value, validationContext.MemberName ?? Name), result);
+            var useName = validationContext.MemberName;
+            if (!string.IsNullOrEmpty(useName))
+            {
+                var pm = ReflectionHelper.FindProperty(validationContext.ObjectType, validationContext.MemberName);
+                if (pm != null)
+                {
+                    var at = pm.GetCustomAttribute<FhirElementAttribute>();
+                    if (at != null)
+                        useName = at.Name;
+                }
+            }
+            DotNetAttributeValidation.TryValidate(value, validationContext.IntoPath(value, useName ?? Name), result);
         }
     }
 }

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

@@ -15,6 +15,7 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
+using System.Reflection;
 #pragma warning disable CS1580 // Invalid type for parameter in XML comment cref attribute
 #pragma warning disable CS1584 // XML comment has syntactically incorrect cref attribute
 
@@ -88,7 +89,13 @@ public void ValidateInstance(object? instance, in InstanceDeserializationContext
                     {
                         // Add the name of the property to the path, so we can display the correct name of the element,
                         // even if it does not really contain any values.
-                        var nestedContext = validationContext.IntoEmptyProperty(propMapping.Name);
+                        var useName = propMapping.Name;
+                        // Use the fhir property name, not the .NET property name.
+                        var at = propMapping.NativeProperty.GetCustomAttribute<FhirElementAttribute>();
+                        if (at != null)
+                            useName = at.Name;
+
+                        var nestedContext = validationContext.IntoEmptyProperty(useName);
 
                         errors = add(errors, runAttributeValidation(propValue, new[] { cardinality }, nestedContext));
                     }

src/Hl7.Fhir.Base/Utility/ExtendedCodedException.cs

@@ -43,10 +43,20 @@ public ExtendedCodedException(
 
         private static string formatLocationMessage(string baseMessage, string? instancePath, long? lineNumber, long? position)
         {
-            string location = $"At line {lineNumber}, position {position}";
+            // If there is no location data, just return the base message
+            if (string.IsNullOrEmpty(instancePath) && !lineNumber.HasValue && !position.HasValue)
+                return baseMessage;
+
+            string? location = null;
             if (!string.IsNullOrEmpty(instancePath))
-                location = $"At {instancePath}, line {lineNumber}, position {position}";
-            var messageWithLocation = $"{baseMessage} {location}";
+                location += instancePath;
+            if (lineNumber.HasValue && position.HasValue)
+            {
+                if (!string.IsNullOrEmpty(location))
+                    location += ", ";
+                location += $"line {lineNumber}, position {position}";
+            }
+            var messageWithLocation = $"{baseMessage} At {location}";
             return messageWithLocation;
         }
 

src/Hl7.Fhir.Base/Validation/CodedValidationException.cs

@@ -6,9 +6,11 @@
  * available at https://raw.githubusercontent.com/FirelyTeam/firely-net-sdk/master/LICENSE
  */
 
+using Hl7.Fhir.Introspection;
 using Hl7.Fhir.Model;
 using Hl7.Fhir.Utility;
 using System.ComponentModel.DataAnnotations;
+using System.Reflection;
 using COVE = Hl7.Fhir.Validation.CodedValidationException;
 using OO_Sev = Hl7.Fhir.Model.OperationOutcome.IssueSeverity;
 using OO_Typ = Hl7.Fhir.Model.OperationOutcome.IssueType;
@@ -93,7 +95,21 @@ internal static CodedValidationException Initialize(ValidationContext context, s
                 // will return the parent, so we need to add the MemberName.
                 if (context.MemberName is not null)
                 {
-                    path = $"{path}.{context.MemberName}";
+                    var useName = context.MemberName;
+                    var pm = ReflectionHelper.FindProperty(context.ObjectType, context.MemberName);
+                    if (pm != null)
+                    {
+                        var at = pm.GetCustomAttribute<FhirElementAttribute>();
+                        if (at != null)
+                        {
+                            useName = at.Name;
+                            if (at.IsPrimitiveValue)
+                                useName = null;
+                        }
+                    }
+
+                    if (!string.IsNullOrEmpty(useName))
+                        path = $"{path}.{useName}";
                 }
             }
 

src/Hl7.Fhir.Shared.Tests/Validation/ValidatePatient.cs

@@ -10,9 +10,11 @@
 using Hl7.Fhir.Serialization;
 using Hl7.Fhir.Validation;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.IO;
+using System.Linq;
 using System.Xml;
 
 namespace Hl7.Fhir.Tests.Validation
@@ -33,6 +35,7 @@ public void ValidateDemoPatient()
 
             Assert.IsFalse(DotNetAttributeValidation.TryValidate(patient, results, true));
             Assert.IsTrue(results.Count > 0);
+            Console.WriteLine(string.Join("\n", results.Select(r => r.ErrorMessage)));
 
             results.Clear();
             foreach (DomainResource contained in patient.Contained) contained.Text = null;
@@ -46,6 +49,7 @@ public void ValidateDemoPatient()
 
             Assert.IsFalse(DotNetAttributeValidation.TryValidate(patient, results, true));
             Assert.IsTrue(results.Count > 0);
+            Console.WriteLine(string.Join("\n", results.Select(r => r.ErrorMessage)));
         }
     }
 }

src/Hl7.Fhir.Shared.Tests/Validation/ValidationTests.cs

@@ -36,7 +36,7 @@ public void TestIdValidation()
             validateErrorOrFail(id);
 
             id = new Id("123456789012345678901234567890123456745290123456745290123456745290123456745290");
-            validateErrorOrFail(id);
+            validateErrorOrFail(id, errorMessage: "'123456789012345678901234567890123456745290123456745290123456745290123456745290' is not a correct literal for an id. At Id");
         }
 
         [TestMethod]
@@ -63,7 +63,7 @@ public void ValidatesResourceTag()
             Assert.IsFalse(DotNetAttributeValidation.TryValidate(p, recurse: true));
         }
 
-        private static void validateErrorOrFail(Base instance, bool recurse = false, string membername = null)
+        private static void validateErrorOrFail(Base instance, bool recurse = false, string membername = null, string errorMessage = null)
         {
             try
             {
@@ -73,8 +73,11 @@ private static void validateErrorOrFail(Base instance, bool recurse = false, str
             }
             catch (ValidationException ve)
             {
+                Console.WriteLine($"Error: {ve.ValidationResult?.ErrorMessage}");
                 if (membername != null)
                     Assert.IsTrue(ve.ValidationResult.MemberNames.Contains(membername));
+                if (errorMessage != null)
+                    Assert.AreEqual(errorMessage, ve.ValidationResult.ErrorMessage);
             }
         }
 
@@ -213,7 +216,7 @@ public void ValidateResourceWithIncorrectChildElement()
             DotNetAttributeValidation.Validate(obs);
 
             // When we recurse, this should fail
-            validateErrorOrFail(obs, true, membername: "Value");
+            validateErrorOrFail(obs, true, membername: "Value", errorMessage: "'Ewout Kramer' is not a correct literal for a dateTime. At Observation.effective.start");
         }
 
 #if !NETSTANDARD1_6
@@ -230,7 +233,7 @@ public void TestXhtmlValidation()
             validateErrorOrFail(p, true);
 
             p.Text.Div = "<div xmlns='http://www.w3.org/1999/xhtml'><img onmouseover='bigImg(this)' src='smiley.gif' alt='Smiley' /></div>";
-            validateErrorOrFail(p, true);
+            validateErrorOrFail(p, true, null, "Value is not well-formed Xml adhering to the FHIR schema for Narrative: The 'onmouseover' attribute is not declared. At Patient.text.div");
         }
 #endif