io.realm

Interface OrderedCollectionChangeSet

public interface OrderedCollectionChangeSet

This interface describes the changes made to a collection during the last update.

OrderedCollectionChangeSet is passed to the OrderedRealmCollectionChangeListener which is registered by RealmResults.addChangeListener(OrderedRealmCollectionChangeListener).

The change information is available in two formats: a simple array of row indices in the collection for each type of change, or an array of OrderedCollectionChangeSet.Ranges.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	OrderedCollectionChangeSet.Range
static class	OrderedCollectionChangeSet.State State describing the nature of the changeset.

Method Summary

Modifier and Type	Method and Description
OrderedCollectionChangeSet.Range[]	getChangeRanges() The modified ranges of objects in the new version of the collection.
int[]	getChanges() The modified indices in the new version of the collection.
OrderedCollectionChangeSet.Range[]	getDeletionRanges() The deleted ranges of objects in the previous version of the collection.
int[]	getDeletions() The deleted indices in the previous version of the collection.
Throwable	getError() Returns any error that happened.
OrderedCollectionChangeSet.Range[]	getInsertionRanges() The inserted ranges of objects in the new version of the collection.
int[]	getInsertions() The inserted indices in the new version of the collection.
OrderedCollectionChangeSet.State	getState() Returns the state represented by this change.
boolean	isCompleteResult() Returns true if the query result is considered "complete".

Method Detail

getState

OrderedCollectionChangeSet.State getState()

Returns the state represented by this change. See OrderedCollectionChangeSet.State for a description of the different states a changeset can be in.

Returns:

what kind of state is represented by this changeset.

See Also:

OrderedCollectionChangeSet.State

getDeletions

int[] getDeletions()

The deleted indices in the previous version of the collection.

Returns:

the indices array. A zero-sized array will be returned if no objects were deleted.

getInsertions

int[] getInsertions()

The inserted indices in the new version of the collection.

Returns:

the indices array. A zero-sized array will be returned if no objects were inserted.

getChanges

int[] getChanges()

The modified indices in the new version of the collection.

For RealmResults, this means that one or more of the properties of the object at the given index were modified (or an object linked to by that object was modified).

Returns:

the indices array. A zero-sized array will be returned if objects were modified.

getDeletionRanges

OrderedCollectionChangeSet.Range[] getDeletionRanges()

The deleted ranges of objects in the previous version of the collection.

Returns:

the OrderedCollectionChangeSet.Range array. A zero-sized array will be returned if no objects were deleted.

getInsertionRanges

OrderedCollectionChangeSet.Range[] getInsertionRanges()

The inserted ranges of objects in the new version of the collection.

Returns:

the OrderedCollectionChangeSet.Range array. A zero-sized array will be returned if no objects were inserted.

getChangeRanges

OrderedCollectionChangeSet.Range[] getChangeRanges()

The modified ranges of objects in the new version of the collection.

Returns:

the OrderedCollectionChangeSet.Range array. A zero-sized array will be returned if no objects were modified.

getError

Throwable getError()

Returns any error that happened. If an error has happened, the state of the collection and other changeset information is undefined. It is possible for a collection to go into an error state after being created and starting to send updates.

Returns:

the error that happened.

isCompleteResult

boolean isCompleteResult()

Returns true if the query result is considered "complete". For all local Realms, or fully synchronized Realms, this method will always return true.

This method thus only makes sense for partially synchronized Realms (as defined by setting SyncConfiguration.Builder.partialRealm().

For those Realms, data is only downloaded when queried which means that until the data is downloaded, a local query might return a query result that would not have been possible on a fully synchronized Realm.

Consider the following case:

1. An app is online and makes a query for all messages containing the word "Realm".
2. Query-based synchronization downloads all those messages.
3. The app goes offline.
4. The app makes an offline query against all messages containing the word "Database".

Here there are two situations where the query result might be considered "incomplete".

The first is when the "Realm" query runs for the first time. The local query will finish faster than the network can download data so the query will initially report an empty incomplete query result.

The second is when the "Database" query is run. The initial query result will not be empty, but contain all messages that contain both "Realm" and "Database", as they are already available offline.

In both cases, a new notification will be triggered as soon as the device is able to download the data required to produce a "complete" query result.

Returns:

true if the query result is fully consistent with the server at some point in time. false if the query was executed while the device was offline or all data has not been downloaded yet.