/// <summary>
/// Retrieves a message value for the specified option field.
/// </summary>
/// <param name="field">The field to fetch the value for.</param>
/// <param name="value">The output variable to populate.</param>
/// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
public bool TryGetMessage <T>(int field, out T value) where T : class, IMessage, new()
{
if (values == null)
{
value = default(T);
return(false);
}
IExtensionValue extensionValue;
if (values.TryGetValue(field, out extensionValue))
{
if (extensionValue is ExtensionValue <T> )
{
ExtensionValue <T> single = extensionValue as ExtensionValue <T>;
ByteString bytes = single.GetValue().ToByteString();
value = new T();
value.MergeFrom(bytes);
return(true);
}
else if (extensionValue is RepeatedExtensionValue <T> )
{
RepeatedExtensionValue <T> repeated = extensionValue as RepeatedExtensionValue <T>;
value = repeated.GetValue()
.Select(v => v.ToByteString())
.Aggregate(new T(), (t, b) =>
{
t.MergeFrom(b);
return(t);
});
return(true);
}
}
value = null;
return(false);
}
private bool TryGetPrimitiveValue <T>(int field, out T value)
{
if (values == null)
{
value = default(T);
return(false);
}
IExtensionValue extensionValue;
if (values.TryGetValue(field, out extensionValue))
{
if (extensionValue is ExtensionValue <T> )
{
ExtensionValue <T> single = extensionValue as ExtensionValue <T>;
value = single.GetValue();
return(true);
}
else if (extensionValue is RepeatedExtensionValue <T> )
{
RepeatedExtensionValue <T> repeated = extensionValue as RepeatedExtensionValue <T>;
if (repeated.GetValue().Count != 0)
{
RepeatedField <T> repeatedField = repeated.GetValue();
value = repeatedField[repeatedField.Count - 1];
return(true);
}
}
else // and here we find explicit enum handling since T : Enum ! x is ExtensionValue<Enum>
{
var type = extensionValue.GetType();
if (type.GetGenericTypeDefinition() == typeof(ExtensionValue <>))
{
var typeInfo = type.GetTypeInfo();
var typeArgs = typeInfo.GenericTypeArguments;
if (typeArgs.Length == 1 && typeArgs[0].GetTypeInfo().IsEnum)
{
value = (T)typeInfo.GetDeclaredMethod(nameof(ExtensionValue <T> .GetValue)).Invoke(extensionValue, EmptyParameters);
return(true);
}
}
else if (type.GetGenericTypeDefinition() == typeof(RepeatedExtensionValue <>))
{
var typeInfo = type.GetTypeInfo();
var typeArgs = typeInfo.GenericTypeArguments;
if (typeArgs.Length == 1 && typeArgs[0].GetTypeInfo().IsEnum)
{
var values = (IList)typeInfo.GetDeclaredMethod(nameof(RepeatedExtensionValue <T> .GetValue)).Invoke(extensionValue, EmptyParameters);
if (values.Count != 0)
{
value = (T)values[values.Count - 1];
return(true);
}
}
}
}
}
value = default(T);
return(false);
}