/// <summary>
/// Resolves a value to an instance of <see cref="Lazy{T}"/>, where the lazily-loaded
/// object is an instance of <see cref="DataObject"/>.
/// </summary>
private static Object ResolveLazilyLoadedDataObject <T>(String value) where T : DataObject
{
var registry = DataObjectRegistries.Get <T>();
var reference = DataObjectRegistries.ResolveReference(value);
return(new Lazy <T>(() => registry.GetObject(reference)));
}
/// <summary>
/// Creates an object from the specified value string.
/// </summary>
/// <param name="value">The value string from which to create the object.</param>
/// <param name="type">The type of object to create.</param>
/// <param name="provider">An object that supplies culture-specific formatting information.</param>
/// <param name="ignoreCase">A value indicating whether to ignore casing whenever relevant (particularly, when converting enum values).</param>
/// <returns>The object that was created.</returns>
public static Object FromString(String value, Type type, IFormatProvider provider, Boolean ignoreCase)
{
// Ensure that the static constructor for this class has been run, as it
// might need to register custom resolvers.
RuntimeHelpers.RunClassConstructor(type.TypeHandle);
// Handle some special cases...
if (type == typeof(Char?))
{
if (value == null)
{
return(null);
}
if (value.Length > 1)
{
throw new FormatException();
}
return(value[0]);
}
if (type == typeof(Char))
{
if (value.Length > 1)
{
throw new FormatException();
}
return(value[0]);
}
if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable <>))
{
if (value == null)
{
return(null);
}
type = type.GetGenericArguments()[0];
}
// Handle custom resolvers.
CustomObjectResolver customResolver;
if (registeredCustomResolvers.TryGetValue(type, out customResolver))
{
return(customResolver(value, provider));
}
// Handle enumerations.
if (type.IsEnum)
{
return(ParseEnum(type, value, ignoreCase));
}
// Handle lazy loaders.
Type dataObjectType;
if (IsLazilyLoadedDataObjectType(type, out dataObjectType))
{
return(miResolveLazilyLoadedDataObject.MakeGenericMethod(dataObjectType)
.Invoke(null, new object[] { value }));
}
// Handle object references.
if (type.Equals(typeof(Guid)))
{
return(DataObjectRegistries.ResolveReference(value).Value);
}
if (type.Equals(typeof(ResolvedDataObjectReference)))
{
if (value == "(none)" || String.IsNullOrEmpty(value))
{
return(new ResolvedDataObjectReference());
}
return(DataObjectRegistries.ResolveReference(value));
}
// Handle the general case by calling the type's Parse() method, if it exists,
// and doing a type conversion if it does not.
Object result;
if (AttemptCultureAwareParse(value, type, provider, out result))
{
return(result);
}
if (AttemptCultureIgnorantParse(value, type, out result))
{
return(result);
}
return(Convert.ChangeType(value, type, provider));
}