private static ObjectDeltaResult Delta(JObject source, JObject target)
{
var result = new ObjectDeltaResult();
// check for null values
if (source == null && target == null)
{
return(result);
}
if (source == null || target == null)
{
result.OldValues = source;
result.NewValues = target;
return(result);
}
// compare internal fields
var removedNew = new JArray();
var removedOld = new JArray();
JToken token;
// start by iterating in source fields
foreach (var i in source)
{
// check if field exists
if (!target.TryGetValue(i.Key, out token))
{
AddOldValuesToken(result, i.Value, i.Key);
removedNew.Add(i.Key);
}
// compare field values
else
{
DeltaField(i.Key, i.Value, token, result);
}
}
// then iterate in target fields that are not present in source
foreach (var i in target)
{
// ignore alredy compared values
if (source.TryGetValue(i.Key, out token))
{
continue;
}
// add missing tokens
removedOld.Add(i.Key);
AddNewValuesToken(result, i.Value, i.Key);
}
if (removedOld.Count > 0)
{
AddOldValuesToken(result, removedOld, PREFIX_REMOVED_FIELDS);
}
if (removedNew.Count > 0)
{
AddNewValuesToken(result, removedNew, PREFIX_REMOVED_FIELDS);
}
return(result);
}
private static void AddOldValuesToken(ObjectDeltaResult item, JToken oldToken, string fieldName)
{
if (item.OldValues == null)
{
item.OldValues = new JObject();
}
item.OldValues[fieldName] = oldToken;
}
public static T PatchObject <T>(T source, ObjectDeltaResult deltaResult) where T : class
{
var patched = PatchObject(source, deltaResult.OldValues);
return(PatchObject(patched, deltaResult.NewValues));
}
private static void AddToken(ObjectDeltaResult item, string fieldName, ObjectDeltaResult delta)
{
AddToken(item, fieldName, delta.OldValues, delta.NewValues);
}
private static void AddToken(ObjectDeltaResult item, string fieldName, JToken oldToken, JToken newToken)
{
AddOldValuesToken(item, oldToken, fieldName);
AddNewValuesToken(item, newToken, fieldName);
}
private static void DeltaField(string fieldName, JToken source, JToken target, ObjectDeltaResult result = null)
{
if (result == null)
{
result = new ObjectDeltaResult();
}
if (source == null)
{
if (target != null)
{
AddToken(result, fieldName, source, target);
}
}
else if (target == null)
{
AddToken(result, fieldName, source, target);
}
else
{
switch (source.Type)
{
case JTokenType.Object:
var v = target as JObject;
var r = Delta(source as JObject, v);
if (!r.AreEqual)
{
AddToken(result, fieldName, r);
}
break;
case JTokenType.Array:
var aS = source as JArray;
var aT = target as JArray;
if ((aS.Count == 0 || aT.Count == 0) && (aS.Count != aT.Count))
{
AddToken(result, fieldName, source, target);
}
else
{
var arrayDelta = new ObjectDeltaResult();
var minCount = Math.Min(aS.Count, aT.Count);
for (var i = 0; i < Math.Max(aS.Count, aT.Count); i++)
{
if (i < minCount)
{
DeltaField(i.ToString(), aS[i], aT[i], arrayDelta);
}
else if (i >= aS.Count)
{
AddNewValuesToken(arrayDelta, aT[i], i.ToString());
}
else
{
AddOldValuesToken(arrayDelta, aS[i], i.ToString());
}
}
if (arrayDelta.AreEqual)
{
return;
}
if (aS.Count != aT.Count)
{
AddToken(arrayDelta, PREFIX_ARRAY_SIZE, aS.Count, aT.Count);
}
AddToken(result, fieldName, arrayDelta);
}
break;
default:
if (!JToken.DeepEquals(source, target))
{
AddToken(result, fieldName, source, target);
}
break;
}
}
}
