feat(*): add identifier attribute

AccordProject.Concerto.Tests/ConcertoUtilsTests.cs

@@ -104,4 +104,46 @@ public void CannotParseTypeWithEmptyVersion()
         var ex = Assert.Throws<Exception>(() => ConcertoUtils.ParseType("org.example@.Foo"));
         Assert.Equal("Invalid fully qualified name \"org.example@.Foo\"", ex.Message);
     }
+
+    [Fact]
+    public void HasIdentifierTrueForTypeWithIdentifier()
+    {
+        var employee = new Employee() { EmployeeId = "12345678" };
+        Assert.True(ConcertoUtils.HasIdentifier(employee));
+    }
+
+    [Fact]
+    public void HasIdentifierTrueForTypeWithInheritedIdentifier()
+    {
+        var manager = new Manager() { EmployeeId = "12345678" };
+        Assert.True(ConcertoUtils.HasIdentifier(manager));
+    }
+
+    [Fact]
+    public void HasIdentifierFalseForTypeWithoutIdentifier()
+    {
+        var project = new Project() {};
+        Assert.False(ConcertoUtils.HasIdentifier(project));
+    }
+
+    [Fact]
+    public void GetIdentifierReturnsForTypeWithIdentifier()
+    {
+        var employee = new Employee() { EmployeeId = "12345678" };
+        Assert.Equal("12345678", ConcertoUtils.GetIdentifier(employee));
+    }
+
+    [Fact]
+    public void GetIdentifierReturnsForTypeWithInheritedIdentifier()
+    {
+        var manager = new Manager() { EmployeeId = "12345678" };
+        Assert.Equal("12345678", ConcertoUtils.GetIdentifier(manager));
+    }
+
+    [Fact]
+    public void GetIdentifierReturnsForTypeWithoutIdentifier()
+    {
+        var project = new Project() {};
+        Assert.Null(ConcertoUtils.GetIdentifier(project));
+    }
 }

AccordProject.Concerto.Tests/TestTypes.cs

@@ -42,6 +42,7 @@ public class Employee : Person {
    public Department? Department { get; set; }
    [Newtonsoft.Json.JsonProperty("manager")]
    public Employee Manager { get; set; }
+   [AccordProject.Concerto.Identifier()]
    [Newtonsoft.Json.JsonProperty("employeeId")]
    public string EmployeeId { get; set; }
 }
@@ -53,3 +54,9 @@ public class Manager : Employee {
    [Newtonsoft.Json.JsonProperty("budget")]
    public float Budget { get; set; }
 }
+[AccordProject.Concerto.Type(Namespace = "org.accordproject.concerto.test", Version = "1.2.3", Name = "Project")]
+[Newtonsoft.Json.JsonConverter(typeof(AccordProject.Concerto.ConcertoConverterNewtonsoft))]
+public class Project : Concept {
+   [Newtonsoft.Json.JsonProperty("$class")]
+   public override string _Class { get; } = "org.accordproject.concerto.test@1.2.3.Project";
+}

AccordProject.Concerto.Tests/data/employee.cto

@@ -37,3 +37,7 @@ participant Employee identified by employeeId extends Person  {
 participant Manager extends Employee  {
     o Double budget optional
 }
+
+concept Project {
+
+}

AccordProject.Concerto/ConcertoAttributes.cs

@@ -15,7 +15,8 @@
 namespace AccordProject.Concerto;
 
 [AttributeUsage(AttributeTargets.Class)]
-public class TypeAttribute : Attribute {
+public class TypeAttribute : Attribute
+{
     public string Namespace;
     public string? Version;
     public string Name;
@@ -29,3 +30,9 @@ public ConcertoType ToType()
         };
     }
 }
+
+[AttributeUsage(AttributeTargets.Property)]
+public class IdentifierAttribute : Attribute
+{
+
+}

AccordProject.Concerto/ConcertoTypes.cs

@@ -24,6 +24,7 @@ public abstract class Concept {
 public abstract class Asset : Concept {
    [Newtonsoft.Json.JsonProperty("$class")]
    public override string _Class { get; } = "concerto@1.0.0.Asset";
+   [AccordProject.Concerto.Identifier()]
    [Newtonsoft.Json.JsonProperty("$identifier")]
    public string _Identifier { get; set; }
 }
@@ -32,6 +33,7 @@ public abstract class Asset : Concept {
 public abstract class Participant : Concept {
    [Newtonsoft.Json.JsonProperty("$class")]
    public override string _Class { get; } = "concerto@1.0.0.Participant";
+   [AccordProject.Concerto.Identifier()]
    [Newtonsoft.Json.JsonProperty("$identifier")]
    public string _Identifier { get; set; }
 }

AccordProject.Concerto/ConcertoUtils.cs

@@ -12,6 +12,10 @@
  * limitations under the License.
  */
 
+namespace AccordProject.Concerto;
+
+using System.Reflection;
+
 /// <summary>
 /// This class represents a Concerto type, for example org.example@1.2.3.Foo.
 /// </summary>
@@ -107,4 +111,38 @@ public static ConcertoType ParseType(string fqn)
         }
         return new ConcertoType() { Namespace = ns, Version = version, Name = name };
     }
+
+    public static bool HasIdentifier(Concept concept)
+    {
+        var type = concept.GetType();
+        var identifierProperty = FindIdentifierProperty(type);
+        return identifierProperty is not null;
+    }
+
+    public static string? GetIdentifier(Concept concept)
+    {
+        var type = concept.GetType();
+        var identifierProperty = FindIdentifierProperty(type);
+        if (identifierProperty is null)
+        {
+            return null;
+        }
+        return identifierProperty.GetValue(concept) as string;
+    }
+
+    private static PropertyInfo? FindIdentifierProperty(Type type)
+    {
+        var properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly);
+        var identifierProperty = properties.FirstOrDefault(property => property.GetCustomAttributes(typeof(IdentifierAttribute), false).Length > 0);
+        if (identifierProperty is not null)
+        {
+            return identifierProperty;
+        }
+        var baseType = type.BaseType;
+        if (baseType is null)
+        {
+            return null;
+        }
+        return FindIdentifierProperty(baseType);
+    }
 }