/// <summary>
/// Creates the <see cref="RegistrationBuilder" /> builder instance to be used in
/// conjunction with the project's <see cref="AssemblyCatalog" /> instance.
/// </summary>
/// <returns>
/// The <see cref="RegistrationBuilder" /> builder instance to be used in
/// conjunction with the project's <see cref="AssemblyCatalog" /> instance.
/// </returns>
/// <remarks>
/// In a nutshell, the instance returned by this method represents the following
/// export rules: "For each type defined within the current assembly that has the
/// <see cref="OperationAttribute" /> applied to it, export all
/// <see cref="IOperation{T}" /> interfaces that it implements; a class may
/// implement the interface multiple times - for different generic arguments
/// (operand types)."
///
/// In addition, the metadata (i.e., name and symbol) expressed by individual
/// classes' <see cref="OperationAttribute" /> instances is added accordingly.
/// </remarks>
private static RegistrationBuilder CreateRegistrationBuilder()
{
var registrationBuilder = new RegistrationBuilder();
Type currentType = null;
var processedTypes = new HashSet <Type>();
registrationBuilder
.ForTypesMatching(IsOperationType)
.ExportInterfaces(IsOperationInterface, ExportInterface);
return(registrationBuilder);
bool IsOperationType(Type type)
{
currentType = type;
return(GetOperationAttribute(type) != null);
};
void ExportInterface(Type interfaceType, ExportBuilder exportBuilder)
{
exportBuilder.AsContractType(interfaceType);
if (processedTypes.Add(currentType))
{
OperationAttribute attribute = GetOperationAttribute(currentType);
exportBuilder.AddMetadata(nameof(attribute.Name), attribute.Name);
exportBuilder.AddMetadata(nameof(attribute.Symbol), attribute.Symbol);
}
};
}
/// <summary>
/// Retrieves metadata for the operation(s) represented by the specified type
/// (class).
/// </summary>
/// <param name="operationType">
/// The type (class) representing the operation(s) to retrieve metadata for.
/// </param>
/// <returns>
/// The metadata for the operation(s) represented by the specified type (class).
/// </returns>
public OperationMetadata GetMetadata(Type operationType)
{
OperationAttribute attribute =
operationType.GetCustomAttribute <OperationAttribute>();
return(new OperationMetadata(attribute.Name, attribute.Symbol));
}
/// <summary>
/// Retrieves metadata for the operation(s) represented by the specified type
/// (class).
/// </summary>
/// <param name="operationType">
/// The type (class) representing the operation(s) to retrieve metadata for.
/// </param>
/// <returns>
/// The metadata for the operation(s) represented by the specified type (class).
/// </returns>
public OperationMetadata GetMetadata(Type operationType)
{
OperationAttribute attribute =
operationType.GetCustomAttribute <OperationAttribute>();
return(new OperationMetadata(
new Dictionary <string, object>()
{
[nameof(attribute.Name)] = attribute.Name,
[nameof(attribute.Symbol)] = attribute.Symbol
}));
}
GetCustomAttributes(Type reflectedType, MemberInfo member)
{
IEnumerable <Attribute> attributes = Enumerable.Empty <Attribute>();
if (member is Type type)
{
OperationAttribute operationAttribute =
type.GetCustomAttribute <OperationAttribute>();
if (operationAttribute != null)
{
attributes = this.GetExportAttributes(type, operationAttribute);
}
}
return(attributes);
}
private IEnumerable <Attribute> GetExportAttributes(
Type operationType, OperationAttribute operationAttribute)
{
var attributes = new List <Attribute>();
attributes.AddRange(
operationType
.GetInterfaces()
.Where(this.IsOperationInterface)
.Select(interfaceType => new ExportAttribute(interfaceType)));
attributes.Add(new ExportMetadataAttribute(
nameof(operationAttribute.Name), operationAttribute.Name));
attributes.Add(new ExportMetadataAttribute(
nameof(operationAttribute.Symbol), operationAttribute.Symbol));
return(attributes);
}