InvalidationTracker
public
class
InvalidationTracker
extends Object
java.lang.Object | |
↳ | androidx.room.InvalidationTracker |
InvalidationTracker keeps a list of tables modified by queries and notifies its callbacks about these tables.
Summary
Nested classes | |
---|---|
class |
InvalidationTracker.Observer
An observer that can listen for changes in the database. |
Public methods | |
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void
|
addObserver(InvalidationTracker.Observer observer)
Adds the given observer to the observers list and it will be notified if any table it observes changes. |
void
|
refreshVersionsAsync()
Enqueues a task to refresh the list of updated tables. |
void
|
removeObserver(InvalidationTracker.Observer observer)
Removes the observer from the observers list. |
Inherited methods | |
---|---|
Public methods
addObserver
public void addObserver (InvalidationTracker.Observer observer)
Adds the given observer to the observers list and it will be notified if any table it observes changes.
Database changes are pulled on another thread so in some race conditions, the observer might be invoked for changes that were done before it is added.
If the observer already exists, this is a no-op call.
If one of the tables in the Observer does not exist in the database, this method throws an
IllegalArgumentException
.
This method should be called on a background/worker thread as it performs database operations.
Parameters | |
---|---|
observer |
InvalidationTracker.Observer : The observer which listens the database for changes.
|
refreshVersionsAsync
public void refreshVersionsAsync ()
Enqueues a task to refresh the list of updated tables.
This method is automatically called when RoomDatabase.endTransaction()
is called but
if you have another connection to the database or directly use SupportSQLiteDatabase
, you may need to call this manually.
removeObserver
public void removeObserver (InvalidationTracker.Observer observer)
Removes the observer from the observers list.
This method should be called on a background/worker thread as it performs database operations.
Parameters | |
---|---|
observer |
InvalidationTracker.Observer : The observer to remove.
|
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Last updated 2021-02-24 UTC.