/// <summary>
/// Reads the option value
/// </summary>
/// <typeparam name="T">Option type</typeparam>
/// <param name="option">Option reference</param>
/// <returns>Option value</returns>
public T Read <T>(Option <T> option)
{
CheckConfigured();
CheckCanParse(option.NonNullableType);
OptionValue optionValue;
_nameToOptionValue.TryGetValue(option.Name, out optionValue);
if (!optionValue.IsExpired(_config.CacheTimeout))
{
return((T)optionValue.RawValue);
}
string value = ReadFirstValue(option.Name);
if (value == null)
{
optionValue.RawValue = option.DefaultValue;
}
else if (DefaultParser.IsSupported(option.NonNullableType))
{
object resultObject;
if (DefaultParser.TryParse(value, option.NonNullableType, out resultObject))
{
optionValue.Update <T>((T)resultObject);
}
else
{
optionValue.Update(option.DefaultValue);
}
}
else
{
ITypeParser typeParser = _config.GetParser(option.NonNullableType);
object result;
typeParser.TryParse(value, option.NonNullableType, out result);
optionValue.Update <T>((T)result);
}
OnReadOption(option, optionValue.RawValue);
return((T)optionValue.RawValue);
}
public bool TryParse(Type propertyType, string rawValue, out object result)
{
if (_defaultParser.IsSupported(propertyType)) //type here must be a non-nullable one
{
if (!_defaultParser.TryParse(rawValue, propertyType, out result))
{
return(false);
}
}
else
{
ITypeParser typeParser = GetParser(propertyType);
if (!typeParser.TryParse(rawValue, propertyType, out result))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Initializes a safe parser of type <typeparamref name="T" />.
/// </summary>
/// <returns>
/// A delegate that parses the specified string using the
/// specified format provider to type <typeparamref name="T" />.
/// </returns>
/// <remarks>
/// The underlying parser uses the <see cref="DefaultParser{T}.TryParse" />
/// when the specified string is not null.
/// </remarks>
private static TPF <T?> InitTryParse()
{
return((string s, IFormatProvider provider, out T? result) =>
{
if (s == null)
{
result = default;
return true;
}
if (DefaultParser <T> .TryParse(s, provider, out var r))
{
result = r;
return true;
}
result = default;
return false;
});
}