internal static Metadata.MetadataProvider CreateMetadataProvider(Type dataControllerType)
{
// construct a list of all types in the inheritance hierarchy for the controller
var baseTypes = new List <Type>();
var currType = dataControllerType;
while (currType != typeof(DataController))
{
baseTypes.Add(currType);
Debug.Assert(currType != null, "currType != null");
currType = currType.BaseType;
}
// create our base reflection provider
var providerList = new List <Metadata.MetadataProvider>();
var reflectionProvider = new Metadata.ReflectionMetadataProvider();
// Set the IsEntity function which consults the chain of providers.
Func <Type, bool> isEntityTypeFunc = type => providerList.Any(metadataProvider => metadataProvider.LookUpIsEntityType(type));
reflectionProvider.SetIsEntityTypeFunc(isEntityTypeFunc);
// Now from most derived to base, create any declared metadata providers,
// chaining the instances as we progress. Note that ordering from derived to
// base is important - we want to ensure that any providers the user has placed on
// their DataController directly come before any DAL providers.
Metadata.MetadataProvider currProvider = reflectionProvider;
providerList.Add(currProvider);
// Reflection rather than TD is used here so we only get explicit
// Type attributes. TD inherits attributes by default, even if the
// attributes aren't inheritable.
foreach (var providerAttribute in baseTypes.SelectMany(type => type.GetCustomAttributes <Metadata.MetadataProviderAttribute>(false)))
{
currProvider = providerAttribute.CreateProvider(dataControllerType, currProvider);
currProvider.SetIsEntityTypeFunc(isEntityTypeFunc);
providerList.Add(currProvider);
}
return(currProvider);
}