OnDisconnect
public classOnDisconnect
The OnDisconnect class is used to manage operations that will be run on the server when this client disconnects. It can be used to add or remove data based on a client's connection status. It is very useful in applications looking for 'presence' functionality. Instances of this class are obtained by callingonDisconnect on a Firebase Database ref.
Summary
Public methods | |
|---|---|
@NonNullTask<Void> | cancel()Cancel any disconnect operations that are queued up at this location |
void | Cancel any disconnect operations that are queued up at this location |
@NonNullTask<Void> | Remove the value at this location when the client disconnects |
void | Remove the value at this location when the client disconnects |
@NonNullTask<Void> | Ensure the data at this location is set to the specified value when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
void | setValue(Ensure the data at this location is set to the specified value when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
@NonNullTask<Void> | Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
@NonNullTask<Void> | Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
void | setValue(Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
void | setValue(Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
void | setValue(Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). |
@NonNullTask<Void> | updateChildren(@NonNullMap<String, Object> update)Ensure the data has the specified child values updated when the client is disconnected |
void | updateChildren(Ensure the data has the specified child values updated when the client is disconnected |
Public methods
cancel
public @NonNullTask<Void> cancel()
Cancel any disconnect operations that are queued up at this location
cancel
public void cancel(@NonNullDatabaseReference.CompletionListener listener)
Cancel any disconnect operations that are queued up at this location
| Parameters | |
|---|---|
@NonNullDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has cancelled the operations |
removeValue
public @NonNullTask<Void> removeValue()
Remove the value at this location when the client disconnects
removeValue
public void removeValue(@NullableDatabaseReference.CompletionListener listener)
Remove the value at this location when the client disconnects
| Parameters | |
|---|---|
@NullableDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has queued up the operation |
setValue
public @NonNullTask<Void> setValue(@NullableObject value)
Ensure the data at this location is set to the specified value when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
setValue
public void setValue(
@NullableObject value,
@NullableDatabaseReference.CompletionListener listener
)
Ensure the data at this location is set to the specified value when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
| Parameters | |
|---|---|
@NullableObject value | The value to be set when a disconnect occurs or null to delete the existing value |
@NullableDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has queued up the operation |
setValue
public @NonNullTask<Void> setValue(@NullableObject value, @NullableString priority)
Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
setValue
public @NonNullTask<Void> setValue(@NullableObject value, double priority)
Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
setValue
public void setValue(
@NullableObject value,
@NullableMap priority,
@NullableDatabaseReference.CompletionListener listener
)
Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
| Parameters | |
|---|---|
@NullableObject value | The value to be set when a disconnect occurs or null to delete the existing value |
@NullableMap priority | The priority to be set when a disconnect occurs |
@NullableDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has queued up the operation |
setValue
public void setValue(
@NullableObject value,
@NullableString priority,
@NullableDatabaseReference.CompletionListener listener
)
Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
| Parameters | |
|---|---|
@NullableObject value | The value to be set when a disconnect occurs or null to delete the existing value |
@NullableString priority | The priority to be set when a disconnect occurs or null to clear the existing priority |
@NullableDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has queued up the operation |
setValue
public void setValue(
@NullableObject value,
double priority,
@NullableDatabaseReference.CompletionListener listener
)
Ensure the data at this location is set to the specified value and priority when the client is disconnected (due to closing the browser, navigating to a new page, or network issues). This method is especially useful for implementing "presence" systems, where a value should be changed or cleared when a user disconnects so that they appear "offline" to other users.
| Parameters | |
|---|---|
@NullableObject value | The value to be set when a disconnect occurs or null to delete the existing value |
double priority | The priority to be set when a disconnect occurs |
@NullableDatabaseReference.CompletionListener listener | A listener that will be triggered once the server has queued up the operation |
updateChildren
public @NonNullTask<Void> updateChildren(@NonNullMap<String, Object> update)
Ensure the data has the specified child values updated when the client is disconnected
updateChildren
public void updateChildren(
@NonNullMap<String, Object> update,
@NullableDatabaseReference.CompletionListener listener
)
Ensure the data has the specified child values updated when the client is disconnected
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Last updated 2025-07-21 UTC.