public TypedGraphDelta(Type type, JObject json)
{
if (type == null)
{
throw new ArgumentNullException("type");
}
if (json == null)
{
throw new ArgumentNullException("json");
}
_root = TypedGraphDelta.ReadRoot(type, json);
_children = TypedGraphDelta.ReadChildren(type, json);
}
private static TypedDelta ReadRoot(Type type, JObject json)
{
var root = TypedGraphDelta.CreateDelta(type);
var properties = from property in type.GetProperties()
where
property.PropertyType.IsValueType ||
property.PropertyType == typeof(String) ||
property.PropertyType == typeof(byte[])
select property;
foreach (var property in properties)
{
var path = String.Format("$['{0}']", property.Name);
var value = json.SelectToken(path) as JValue;
if (value != null)
{
var conversionType = TypedGraphDelta.GetConversionType(property.PropertyType);
object convertedValue = null;
if (value.Value != null)
{
if (conversionType == typeof(byte[]))
{
convertedValue = Convert.FromBase64String((string)value.Value);
}
else
{
convertedValue = Convert.ChangeType(value.Value, conversionType);
}
}
root.TrySetPropertyValue(
property.Name,
convertedValue
);
}
}
return(root);
}
public void Patch(object model)
{
if (model == null)
{
throw new ArgumentNullException("model");
}
var type = model.GetType();
//NOTE When using Entity Framework the entities returned are usually proxies extending your code first
//entities, which would break an exact comparison here.
if (!_root.EntityType.IsAssignableFrom(type))
{
throw new InvalidOperationException(
String.Format("Model is of type {0} but delta is for {1}", type.FullName, _root.EntityType.FullName)
);
}
TypedGraphDelta.Patch(_root, model);
foreach (var child in _children)
{
var property = type.GetProperty(child.Key);
object value = null;
//If there is a delta, then apply it to the existing value (or newly created value), otherwise we
//set the property to null.
if (child.Value != null)
{
value = property.GetValue(model);
if (value == null)
{
value = Activator.CreateInstance(property.PropertyType);
}
child.Value.Patch(value);
}
property.SetValue(model, value);
}
}
