com.google.firebase.database

Interfaces

`ChildEventListener`	Classes implementing this interface can be used to receive events about changes in the child locations of a given `DatabaseReference` ref.
`DatabaseReference.CompletionListener`	This interface is used as a method of being notified when an operation has been acknowledged by the Database servers and can be considered complete
`Logger`	This interface is used to setup logging for Realtime Database.
`Transaction.Handler`	An object implementing this interface is used to run a transaction, and will be notified of the results of the transaction.
`ValueEventListener`	Classes implementing this interface can be used to receive events about data changes at a location.

Classes

`ChildEvent`	Used to emit events about changes in the child locations of a given `Query` when using the `childEvents` Flow.
`ChildEvent.Added`	Emitted when a new child is added to the location.
`ChildEvent.Changed`	Emitted when the data at a child location has changed.
`ChildEvent.Moved`	Emitted when a child location's priority changes.
`ChildEvent.Removed`	Emitted when a child is removed from the location.
`DataSnapshot`	A DataSnapshot instance contains data from a Firebase Database location.
`DatabaseError`	Instances of DatabaseError are passed to callbacks when an operation failed.
`DatabaseReference`	A Firebase reference represents a particular location in your Database and can be used for reading or writing data to that Database location.
`FirebaseDatabase`	The entry point for accessing a Firebase Database.
`GenericTypeIndicator`	Due to the way that Java implements generics (type-erasure), it is necessary to use a slightly more complicated method to properly resolve types for generic collections at runtime.
`MutableData`	Instances of this class encapsulate the data and priority at a location.
`OnDisconnect`	The OnDisconnect class is used to manage operations that will be run on the server when this client disconnects.
`Query`	The Query class (and its subclass, `DatabaseReference`) are used for reading data.
`ServerValue`	Contains placeholder values to use when writing data to the Firebase Database.
`Transaction`	The Transaction class encapsulates the functionality needed to perform a transaction on the data at a location.
`Transaction.Result`	Instances of this class represent the desired outcome of a single run of a `Handler`'s doTransaction method.

Exceptions

DatabaseException

This error is thrown when the Firebase Database library is unable to operate on the input it has been given.

Annotations

`Exclude`	Marks a field as excluded from the Database.
`IgnoreExtraProperties`	Properties that don't map to class fields are ignored when serializing to a class annotated with this annotation.
`PropertyName`	Marks a field to be renamed when serialized.
`ThrowOnExtraProperties`	Properties that don't map to class fields when serializing to a class annotated with this annotation cause an exception to be thrown.

Enums

Logger.Level

The log levels used by the Realtime Database library

Extension functions summary

`FirebaseDatabase`	`Firebase.database(app: FirebaseApp, url: String)` Returns the `FirebaseDatabase` instance of the given `FirebaseApp` and `url`.
`FirebaseDatabase`	`Firebase.database(app: FirebaseApp)` Returns the `FirebaseDatabase` instance of the given `FirebaseApp`.
`FirebaseDatabase`	`Firebase.database(url: String)` Returns the `FirebaseDatabase` instance for the specified `url`.
`inline T?`	`<T : Any?> DataSnapshot.getValue()` Returns the content of the DataSnapshot converted to a POJO.
`inline T?`	`<T : Any?> MutableData.getValue()` Returns the content of the MutableData converted to a POJO.
`inline Flow<T?>`	`<T : Any> Query.values()` Starts listening to this query and emits its values converted to a POJO via a `Flow`.

Extension properties summary

`Flow<ChildEvent>`	`Query.childEvents` Starts listening to this query's child events and emits its values via a `Flow`.
`FirebaseDatabase`	`Firebase.database` Returns the `FirebaseDatabase` instance of the default `FirebaseApp`.
`Flow<DataSnapshot>`	`Query.snapshots` Starts listening to this query and emits its values via a `Flow`.

Extension functions

database

fun Firebase.database(app: FirebaseApp, url: String): FirebaseDatabase

Returns the FirebaseDatabase instance of the given FirebaseApp and url.

database

fun Firebase.database(app: FirebaseApp): FirebaseDatabase

Returns the FirebaseDatabase instance of the given FirebaseApp.

database

fun Firebase.database(url: String): FirebaseDatabase

Returns the FirebaseDatabase instance for the specified url.

getValue

inline fun <T : Any?> DataSnapshot.getValue(): T?

Returns the content of the DataSnapshot converted to a POJO.

Supports generics like List<> or Map<>. Use @JvmSuppressWildcards to force the compiler to use the type T, and not ? extends T.

getValue

inline fun <T : Any?> MutableData.getValue(): T?

Returns the content of the MutableData converted to a POJO.

Supports generics like List<> or Map<>. Use @JvmSuppressWildcards to force the compiler to use the type T, and not ? extends T.

values

inline fun <T : Any> Query.values(): Flow<T?>

Starts listening to this query and emits its values converted to a POJO via a Flow.

When the returned flow starts being collected, a ValueEventListener will be attached.
When the flow completes, the listener will be removed.

Extension properties

childEvents

val Query.childEvents: Flow<ChildEvent>

Starts listening to this query's child events and emits its values via a Flow.

When the returned flow starts being collected, a ChildEventListener will be attached.
When the flow completes, the listener will be removed.

database

val Firebase.database: FirebaseDatabase

Returns the FirebaseDatabase instance of the default FirebaseApp.

snapshots

val Query.snapshots: Flow<DataSnapshot>

Starts listening to this query and emits its values via a Flow.

When the returned flow starts being collected, a ValueEventListener will be attached.
When the flow completes, the listener will be removed.