Configuration Helpers

This post is mainly so I’ll be able to find this code later.

I’ve been on multiple projects that make heavy use of configuration and I always end up writing these helpers similar to the ones listed below. These are general conversion routines that take a String and try to cast it to a specified value. In this version, I’ve included a special case when casting to Boolean. A “1” is considered TRUE and “0” FALSE.

 

public bool TryCastFromStringTo<T>(string s, out T value) 
{
	value = default(T); 
	if (typeof(T) == typeof(bool)) 
	{
		if (s.Trim() == "1") 
		{
			value = ((T)(object)true); 
			return true; 
		}
		if (s.Trim() == "0") 
		{
			value = ((T)(object)false); 
			return true; 
		}
	}
	
	TypeConverter converter = TypeDescriptor.GetConverter(typeof(T)); 
	object convertedValue; 
	try 
	{
		convertedValue = converter.ConvertFromString(s); 
	}
	catch (Exception e) 
	{
		if (e is NotSupportedException 
			|| e is InvalidCastException || e is FormatException) 
		{
		return false; 
		}
		if (null != e.InnerException && e.InnerException is FormatException) 
		{
		return false; 
		}
		throw; 
	}
	value = (T) convertedValue; 
	return true; 
}

public T SafelyCastFromStringTo<T>(string value, T defaultValue) 
{
	if (null == value) return defaultValue; 
	T convertedValue; 
	if (this.TryCastFromStringTo(value, out convertedValue)) 
	{
		return convertedValue; 
	}
	return defaultValue; 
}