Advanced

Obtaining Change detailed results

By default, the change result will only contain the number of entries which were changed during the operation. In order to get more details (requires more network traffic) the ChangeModifiers.ReturnDetailedResults should be used. When using this modifier the result will contain the list of entries which were changed including the change affect that took place on each entry. You can use this in order to know what was the affect, for instance what is the value of a numeric property after the increment operation was applied on it.

ISpaceProxy space = // ... obtain a space reference
Guid id = ...;
IdQuery<Account> idQuery = new IdQuery<Account>(id, routing The mechanism that is in charge of routing the objects into and out of the corresponding partitions. The routing is based on a designated attribute inside the objects that are written to the Space, called the Routing Index.);
IChangeResult<Account> changeResult = space.Change(idQuery, new ChangeSet().Increment("balance.euro", 5.2D), ChangeModifiers.ReturnDetailedResults);

foreach(IChangedEntryDetails<Account> changedEntryDetails in changeResult.Results) {
  //Will get the first change which was applied to an entry, in our case we did only single increment so we will have only one change operation.
  //The order is corresponding to the order of operation applied on the `ChangeSet`.
  IChangeOperationResult operationResult = changedEntryDetails.ChangeOperationsResults[0];
  double newValue = IncrementOperation.GetNewValue(operationResult);
  ...
}

Here is the full list of change operations:

ChangeSet operation	ChangeOperation class	Comment
ChangeSet.Set	SetOperation
ChangeSet.Unset	UnsetOperation
ChangeSet.Increment	IncrementOperation
ChangeSet.Decrement	IncrementOperation	will be increment with negative value
ChangeSet.AddToCollection	AddToCollectionOperation
ChangeSet.AddRangeToCollection	AddRangeToCollectionOperation
ChangeSet.RemoveFromCollection	RemoveFromCollectionOperation
ChangeSet.SetInDictionary	SetInDictionaryOperation
ChangeSet.RemoveFromDictionary	RemoveFromDictionaryOperation

Add and Get operation

A common usage pattern is to increment a numeric property of a specific entry and needing the updated value after the increment was applied. Using the AddAndGet operation you can do that using one method call and get an atomic add and get operation semantics. Following is an example of incrementing a property named Counter inside an entry of type WordCount:

ISpaceProxy space = // ... obtain a space reference
Guid id = ...;

IdQuery<WordCount> idQuery = new IdQuery<WordCount>(id, routing);
int? newCounter = ISpaceProxy.AddAndGet(idQuery, "Counter", 1);