Trim all string properties

I fixed landi's answer to accommodate child nullable objects and handle IEnumerable collections (loop through a List of object and trim string properties). I made an edit to his answer which was rejected for not being on topic, but that's a load of garbage. Hopefully this helps someone, as landi's answer didn't work on every object type I had. Now it does.

public static class ExtensionMethods
{
    public static void TrimAllStrings<TSelf>(this TSelf obj)
    {
        if(obj != null)
        {
            if(obj is IEnumerable)
            {
                foreach(var listItem in obj as IEnumerable)
                {
                    listItem.TrimAllStrings();
                }
            }
            else
            {
                BindingFlags flags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.FlattenHierarchy;

                foreach (PropertyInfo p in obj.GetType().GetProperties(flags))
                {
                    Type currentNodeType = p.PropertyType;
                    if (currentNodeType == typeof (String))
                    {
                        string currentValue = (string)p.GetValue(obj, null);
                        if (currentValue != null)
                        {
                            p.SetValue(obj, currentValue.Trim(), null);
                        }
                    }
                    // see http://stackoverflow.com/questions/4444908/detecting-native-objects-with-reflection
                    else if (currentNodeType != typeof (object) && Type.GetTypeCode(currentNodeType) == TypeCode.Object)
                    {
                        p.GetValue(obj, null).TrimAllStrings();
                    }
                }
            }
        }
    }
}

var stringProperties = obj.GetType().GetProperties()
                          .Where(p => p.PropertyType == typeof (string));

foreach (var stringProperty in stringProperties)
{
    string currentValue = (string) stringProperty.GetValue(obj, null);
    stringProperty.SetValue(obj, currentValue.Trim(), null) ;
}

Thank you to Bala R for your solution to the OP's problem. I converted your solution to an extension method and fixed a problem where null values were throwing errors.

    /// <summary>Trim all String properties of the given object</summary>
    public static TSelf TrimStringProperties<TSelf>(this TSelf input)
    {
        var stringProperties = input.GetType().GetProperties()
            .Where(p => p.PropertyType == typeof(string) && p.CanWrite);

        foreach (var stringProperty in stringProperties)
        {
            string currentValue = (string)stringProperty.GetValue(input, null);
            if (currentValue != null)
                stringProperty.SetValue(input, currentValue.Trim(), null);
        }
        return input;
    }