/// <summary>
/// Create a new, empty object of a given type
/// </summary>
/// <param name="assemblyQualifiedFullName">The full name of the type to create, <see cref="Type.AssemblyQualifiedName"/></param>
/// <param name="typeRegistry">A type registry that specifies custom mappings or factories</param>
/// <param name="dimensions">For array types, the dimensions of the array to create</param>
/// <returns></returns>
public object CreateEmptyObject(string assemblyQualifiedFullName, TypeRegistry typeRegistry, params object[] dimensions)
{
return(CreateEmptyObject(assemblyQualifiedFullName, typeRegistry, null, dimensions));
}
/// <summary>
/// Create a new, empty object of a given type
/// </summary>
/// <param name="assemblyQualifiedFullName">The full name of the type to create, <see cref="Type.AssemblyQualifiedName"/></param>
/// <param name="typeRegistry">A type registry that specifies custom mappings or factories</param>
/// <returns></returns>
public object CreateEmptyObject(string assemblyQualifiedFullName, TypeRegistry typeRegistry)
{
return(CreateEmptyObject(assemblyQualifiedFullName, typeRegistry, null, 0));
}
/// <summary>
/// Create a factory for creating any type of object
/// </summary>
/// <param name="typeRegistry">A type registry for custom mappings</param>
public ObjectFactory(TypeRegistry typeRegistry)
{
TypeRegistry = typeRegistry;
}
/// <summary>
/// Create a new, empty object of a given type
/// </summary>
/// <param name="type">The type of object to construct</param>
/// <param name="typeRegistry">A type registry for constructing unknown types</param>
/// <param name="initializer">An optional initializer to use to create the object</param>
/// <param name="dimensions">For array types, the dimensions of the array to create</param>
/// <returns></returns>
public object CreateEmptyObject(Type type, TypeRegistry typeRegistry, Func <object> initializer, params object[] dimensions)
{
var objectType = type;
if (initializer != null)
{
return(initializer());
}
// check the type registry for a custom type mapping
if (typeRegistry?.ContainsType(objectType) == true)
{
objectType = typeRegistry.GetMapping(objectType);
}
// check the type registry for a custom type factory
if (typeRegistry?.ContainsFactoryType(objectType) == true)
{
return(typeRegistry.GetFactory(objectType).Invoke());
}
var typeSupport = new ExtendedType(objectType);
// if we are asked to create an instance of an interface, try to initialize using a valid concrete type
if (typeSupport.IsInterface && !typeSupport.IsEnumerable)
{
// try a known concrete type from typeSupport
var concreteType = typeSupport.KnownConcreteTypes.FirstOrDefault();
if (concreteType == null)
{
throw new TypeSupportException(objectType, $"Unable to locate a concrete type for '{typeSupport.Type.FullName}'! Cannot create instance.");
}
typeSupport = new ExtendedType(concreteType);
}
if (typeSupport.IsArray)
{
object[] createParameters = dimensions;
// we also want to allow passing of collections/lists/arrays so do some conversion first
if (createParameters?.Length > 0)
{
var parameterType = createParameters[0].GetType();
if (parameterType.IsArray)
{
var ar = (Array)createParameters[0];
createParameters = ar.Cast <object>().ToArray();
}
else if (typeof(ICollection).IsAssignableFrom(parameterType) ||
typeof(IList).IsAssignableFrom(parameterType))
{
var ar = (ICollection)createParameters[0];
createParameters = ar.Cast <object>().ToArray();
}
}
if (createParameters != null && createParameters.Length > 1)
{
createParameters.Reverse();
}
if (createParameters == null || createParameters.Length == 0)
{
createParameters = new object[] { 0 }
}
;
return(Activator.CreateInstance(typeSupport.Type, createParameters));
}
else if (typeSupport.IsDictionary)
{
var genericType = typeSupport.Type.GetGenericArguments().ToList();
if (genericType.Count != 2)
{
throw new TypeSupportException(objectType, "IDictionary should contain 2 element types.");
}
Type[] typeArgs = { genericType[0], genericType[1] };
var listType = typeof(Dictionary <,>).MakeGenericType(typeArgs);
var newDictionary = Activator.CreateInstance(listType) as IDictionary;
return(newDictionary);
}
else if (typeSupport.IsEnumerable && !typeSupport.IsImmutable)
{
var genericType = typeSupport.Type.GetGenericArguments().FirstOrDefault();
// test specifically for ICollection and List
var isGenericCollection = typeSupport.Type.IsGenericType &&
typeSupport.Type.GetGenericTypeDefinition() == typeof(ICollection <>);
var isGenericList = typeSupport.Type.IsGenericType &&
typeSupport.Type.GetGenericTypeDefinition() == typeof(List <>);
var isGenericIList = typeSupport.Type.IsGenericType &&
typeSupport.Type.GetGenericTypeDefinition() == typeof(IList <>);
if (!isGenericList && !isGenericIList && !isGenericCollection)
{
var constructors = typeSupport.Type.GetConstructors(ConstructorOptions.All);
if (typeSupport.HasEmptyConstructor)
{
var newList = Activator.CreateInstance(typeSupport.Type);
return(newList);
}
else if (typeSupport.Constructors.Any())
{
// special handling is required here as custom collections can't be properly
// initialized using FormatterServices.GetUninitializedObject()
var constructor = typeSupport.Constructors.First();
var parameters = constructor.GetParameters();
var param = new List <object>();
// initialize using defaults for constructor parameters
foreach (var p in parameters)
{
param.Add(CreateEmptyObject(p.ParameterType));
}
var newList = Activator.CreateInstance(typeSupport.Type, param.ToArray());
return(newList);
}
}
else if (genericType != null)
{
var listType = typeof(List <>).MakeGenericType(genericType);
var newList = (IList)Activator.CreateInstance(listType);
return(newList);
}
return(Enumerable.Empty <object>());
}
else if (typeSupport.Type.ContainsGenericParameters)
{
// create a generic type and create an instance
// to accomplish this, we need to create a new generic type using the type arguments from the interface
// and the concrete class definition. voodoo!
var originalTypeSupport = new ExtendedType(objectType);
var genericArguments = originalTypeSupport.Type.GetGenericArguments();
var newType = typeSupport.Type.MakeGenericType(genericArguments);
object newObject = null;
if (typeSupport.HasEmptyConstructor)
{
newObject = Activator.CreateInstance(newType);
}
else
{
newObject = FormatterServices.GetUninitializedObject(newType);
}
return(newObject);
}
else if (typeSupport.HasEmptyConstructor && !typeSupport.Type.ContainsGenericParameters)
{
return(Activator.CreateInstance(typeSupport.Type));
}
else if (typeSupport.IsImmutable)
{
return(null);
}
return(FormatterServices.GetUninitializedObject(typeSupport.Type));
}
}
/// <summary>
/// Create a new, empty object of a given type
/// </summary>
/// <param name="typeRegistry">A type registry that specifies custom mappings or factories</param>
/// <param name="initializer">An optional initializer to use to create the object</param>
/// <param name="dimensions">For array types, the dimensions of the array to create</param>
/// <returns></returns>
public T CreateEmptyObject <T>(TypeRegistry typeRegistry, Func <T> initializer, params object[] dimensions)
{
return((T)CreateEmptyObject(typeof(T), typeRegistry, initializer as Func <object>, dimensions));
}
/// <summary>
/// Create a new, empty object of a given type
/// </summary>
/// <param name="type">The type to create</param>
/// <param name="typeRegistry">A type registry that specifies custom mappings or factories</param>
/// <param name="dimensions">For array types, the dimensions of the array to create</param>
/// <returns></returns>
public object CreateEmptyObject(Type type, TypeRegistry typeRegistry, params object[] dimensions)
{
return(CreateEmptyObject(type, typeRegistry, null, dimensions));
}