Edit File: Reference_impl.d.ts
/** * @license * Copyright 2020 Google LLC * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import { Repo } from '../core/Repo'; import { Index } from '../core/snap/indexes/Index'; import { Node } from '../core/snap/Node'; import { Path } from '../core/util/Path'; import { Change } from '../core/view/Change'; import { CancelEvent, DataEvent, EventType } from '../core/view/Event'; import { CallbackContext, EventRegistration, QueryContext } from '../core/view/EventRegistration'; import { QueryParams } from '../core/view/QueryParams'; import { Database } from './Database'; import { OnDisconnect } from './OnDisconnect'; import { ListenOptions, Query as Query, DatabaseReference, Unsubscribe, ThenableReference } from './Reference'; /** * @internal */ export declare class QueryImpl implements Query, QueryContext { readonly _repo: Repo; readonly _path: Path; readonly _queryParams: QueryParams; readonly _orderByCalled: boolean; /** * @hideconstructor */ constructor(_repo: Repo, _path: Path, _queryParams: QueryParams, _orderByCalled: boolean); get key(): string | null; get ref(): DatabaseReference; get _queryIdentifier(): string; /** * An object representation of the query parameters used by this Query. */ get _queryObject(): object; isEqual(other: QueryImpl | null): boolean; toJSON(): string; toString(): string; } /** * @internal */ export declare class ReferenceImpl extends QueryImpl implements DatabaseReference { /** @hideconstructor */ constructor(repo: Repo, path: Path); get parent(): ReferenceImpl | null; get root(): ReferenceImpl; } /** * A `DataSnapshot` contains data from a Database location. * * Any time you read data from the Database, you receive the data as a * `DataSnapshot`. A `DataSnapshot` is passed to the event callbacks you attach * with `on()` or `once()`. You can extract the contents of the snapshot as a * JavaScript object by calling the `val()` method. Alternatively, you can * traverse into the snapshot by calling `child()` to return child snapshots * (which you could then call `val()` on). * * A `DataSnapshot` is an efficiently generated, immutable copy of the data at * a Database location. It cannot be modified and will never change (to modify * data, you always call the `set()` method on a `Reference` directly). */ export declare class DataSnapshot { readonly _node: Node; /** * The location of this DataSnapshot. */ readonly ref: DatabaseReference; readonly _index: Index; /** * @param _node - A SnapshotNode to wrap. * @param ref - The location this snapshot came from. * @param _index - The iteration order for this snapshot * @hideconstructor */ constructor(_node: Node, /** * The location of this DataSnapshot. */ ref: DatabaseReference, _index: Index); /** * Gets the priority value of the data in this `DataSnapshot`. * * Applications need not use priority but can order collections by * ordinary properties (see * {@link https://firebase.google.com/docs/database/web/lists-of-data#sorting_and_filtering_data |Sorting and filtering data} * ). */ get priority(): string | number | null; /** * The key (last part of the path) of the location of this `DataSnapshot`. * * The last token in a Database location is considered its key. For example, * "ada" is the key for the /users/ada/ node. Accessing the key on any * `DataSnapshot` will return the key for the location that generated it. * However, accessing the key on the root URL of a Database will return * `null`. */ get key(): string | null; /** Returns the number of child properties of this `DataSnapshot`. */ get size(): number; /** * Gets another `DataSnapshot` for the location at the specified relative path. * * Passing a relative path to the `child()` method of a DataSnapshot returns * another `DataSnapshot` for the location at the specified relative path. The * relative path can either be a simple child name (for example, "ada") or a * deeper, slash-separated path (for example, "ada/name/first"). If the child * location has no data, an empty `DataSnapshot` (that is, a `DataSnapshot` * whose value is `null`) is returned. * * @param path - A relative path to the location of child data. */ child(path: string): DataSnapshot; /** * Returns true if this `DataSnapshot` contains any data. It is slightly more * efficient than using `snapshot.val() !== null`. */ exists(): boolean; /** * Exports the entire contents of the DataSnapshot as a JavaScript object. * * The `exportVal()` method is similar to `val()`, except priority information * is included (if available), making it suitable for backing up your data. * * @returns The DataSnapshot's contents as a JavaScript value (Object, * Array, string, number, boolean, or `null`). */ exportVal(): any; /** * Enumerates the top-level children in the `DataSnapshot`. * * Because of the way JavaScript objects work, the ordering of data in the * JavaScript object returned by `val()` is not guaranteed to match the * ordering on the server nor the ordering of `onChildAdded()` events. That is * where `forEach()` comes in handy. It guarantees the children of a * `DataSnapshot` will be iterated in their query order. * * If no explicit `orderBy*()` method is used, results are returned * ordered by key (unless priorities are used, in which case, results are * returned by priority). * * @param action - A function that will be called for each child DataSnapshot. * The callback can return true to cancel further enumeration. * @returns true if enumeration was canceled due to your callback returning * true. */ forEach(action: (child: DataSnapshot) => boolean | void): boolean; /** * Returns true if the specified child path has (non-null) data. * * @param path - A relative path to the location of a potential child. * @returns `true` if data exists at the specified child path; else * `false`. */ hasChild(path: string): boolean; /** * Returns whether or not the `DataSnapshot` has any non-`null` child * properties. * * You can use `hasChildren()` to determine if a `DataSnapshot` has any * children. If it does, you can enumerate them using `forEach()`. If it * doesn't, then either this snapshot contains a primitive value (which can be * retrieved with `val()`) or it is empty (in which case, `val()` will return * `null`). * * @returns true if this snapshot has any children; else false. */ hasChildren(): boolean; /** * Returns a JSON-serializable representation of this object. */ toJSON(): object | null; /** * Extracts a JavaScript value from a `DataSnapshot`. * * Depending on the data in a `DataSnapshot`, the `val()` method may return a * scalar type (string, number, or boolean), an array, or an object. It may * also return null, indicating that the `DataSnapshot` is empty (contains no * data). * * @returns The DataSnapshot's contents as a JavaScript value (Object, * Array, string, number, boolean, or `null`). */ val(): any; } /** * * Returns a `Reference` representing the location in the Database * corresponding to the provided path. If no path is provided, the `Reference` * will point to the root of the Database. * * @param db - The database instance to obtain a reference for. * @param path - Optional path representing the location the returned * `Reference` will point. If not provided, the returned `Reference` will * point to the root of the Database. * @returns If a path is provided, a `Reference` * pointing to the provided path. Otherwise, a `Reference` pointing to the * root of the Database. */ export declare function ref(db: Database, path?: string): DatabaseReference; /** * Returns a `Reference` representing the location in the Database * corresponding to the provided Firebase URL. * * An exception is thrown if the URL is not a valid Firebase Database URL or it * has a different domain than the current `Database` instance. * * Note that all query parameters (`orderBy`, `limitToLast`, etc.) are ignored * and are not applied to the returned `Reference`. * * @param db - The database instance to obtain a reference for. * @param url - The Firebase URL at which the returned `Reference` will * point. * @returns A `Reference` pointing to the provided * Firebase URL. */ export declare function refFromURL(db: Database, url: string): DatabaseReference; /** * Gets a `Reference` for the location at the specified relative path. * * The relative path can either be a simple child name (for example, "ada") or * a deeper slash-separated path (for example, "ada/name/first"). * * @param parent - The parent location. * @param path - A relative path from this location to the desired child * location. * @returns The specified child location. */ export declare function child(parent: DatabaseReference, path: string): DatabaseReference; /** * Returns an `OnDisconnect` object - see * {@link https://firebase.google.com/docs/database/web/offline-capabilities | Enabling Offline Capabilities in JavaScript} * for more information on how to use it. * * @param ref - The reference to add OnDisconnect triggers for. */ export declare function onDisconnect(ref: DatabaseReference): OnDisconnect; export interface ThenableReferenceImpl extends ReferenceImpl, Pick<Promise<ReferenceImpl>, 'then' | 'catch'> { } /** * Generates a new child location using a unique key and returns its * `Reference`. * * This is the most common pattern for adding data to a collection of items. * * If you provide a value to `push()`, the value is written to the * generated location. If you don't pass a value, nothing is written to the * database and the child remains empty (but you can use the `Reference` * elsewhere). * * The unique keys generated by `push()` are ordered by the current time, so the * resulting list of items is chronologically sorted. The keys are also * designed to be unguessable (they contain 72 random bits of entropy). * * See {@link https://firebase.google.com/docs/database/web/lists-of-data#append_to_a_list_of_data | Append to a list of data} * </br>See {@link ttps://firebase.googleblog.com/2015/02/the-2120-ways-to-ensure-unique_68.html | The 2^120 Ways to Ensure Unique Identifiers} * * @param parent - The parent location. * @param value - Optional value to be written at the generated location. * @returns Combined `Promise` and `Reference`; resolves when write is complete, * but can be used immediately as the `Reference` to the child location. */ export declare function push(parent: DatabaseReference, value?: unknown): ThenableReference; /** * Removes the data at this Database location. * * Any data at child locations will also be deleted. * * The effect of the remove will be visible immediately and the corresponding * event 'value' will be triggered. Synchronization of the remove to the * Firebase servers will also be started, and the returned Promise will resolve * when complete. If provided, the onComplete callback will be called * asynchronously after synchronization has finished. * * @param ref - The location to remove. * @returns Resolves when remove on server is complete. */ export declare function remove(ref: DatabaseReference): Promise<void>; /** * Writes data to this Database location. * * This will overwrite any data at this location and all child locations. * * The effect of the write will be visible immediately, and the corresponding * events ("value", "child_added", etc.) will be triggered. Synchronization of * the data to the Firebase servers will also be started, and the returned * Promise will resolve when complete. If provided, the `onComplete` callback * will be called asynchronously after synchronization has finished. * * Passing `null` for the new value is equivalent to calling `remove()`; namely, * all data at this location and all child locations will be deleted. * * `set()` will remove any priority stored at this location, so if priority is * meant to be preserved, you need to use `setWithPriority()` instead. * * Note that modifying data with `set()` will cancel any pending transactions * at that location, so extreme care should be taken if mixing `set()` and * `transaction()` to modify the same data. * * A single `set()` will generate a single "value" event at the location where * the `set()` was performed. * * @param ref - The location to write to. * @param value - The value to be written (string, number, boolean, object, * array, or null). * @returns Resolves when write to server is complete. */ export declare function set(ref: DatabaseReference, value: unknown): Promise<void>; /** * Sets a priority for the data at this Database location. * * Applications need not use priority but can order collections by * ordinary properties (see * {@link https://firebase.google.com/docs/database/web/lists-of-data#sorting_and_filtering_data | Sorting and filtering data} * ). * * @param ref - The location to write to. * @param priority - The priority to be written (string, number, or null). * @returns Resolves when write to server is complete. */ export declare function setPriority(ref: DatabaseReference, priority: string | number | null): Promise<void>; /** * Writes data the Database location. Like `set()` but also specifies the * priority for that data. * * Applications need not use priority but can order collections by * ordinary properties (see * {@link https://firebase.google.com/docs/database/web/lists-of-data#sorting_and_filtering_data | Sorting and filtering data} * ). * * @param ref - The location to write to. * @param value - The value to be written (string, number, boolean, object, * array, or null). * @param priority - The priority to be written (string, number, or null). * @returns Resolves when write to server is complete. */ export declare function setWithPriority(ref: DatabaseReference, value: unknown, priority: string | number | null): Promise<void>; /** * Writes multiple values to the Database at once. * * The `values` argument contains multiple property-value pairs that will be * written to the Database together. Each child property can either be a simple * property (for example, "name") or a relative path (for example, * "name/first") from the current location to the data to update. * * As opposed to the `set()` method, `update()` can be use to selectively update * only the referenced properties at the current location (instead of replacing * all the child properties at the current location). * * The effect of the write will be visible immediately, and the corresponding * events ('value', 'child_added', etc.) will be triggered. Synchronization of * the data to the Firebase servers will also be started, and the returned * Promise will resolve when complete. If provided, the `onComplete` callback * will be called asynchronously after synchronization has finished. * * A single `update()` will generate a single "value" event at the location * where the `update()` was performed, regardless of how many children were * modified. * * Note that modifying data with `update()` will cancel any pending * transactions at that location, so extreme care should be taken if mixing * `update()` and `transaction()` to modify the same data. * * Passing `null` to `update()` will remove the data at this location. * * See * {@link https://firebase.googleblog.com/2015/09/introducing-multi-location-updates-and_86.html | Introducing multi-location updates and more}. * * @param ref - The location to write to. * @param values - Object containing multiple values. * @returns Resolves when update on server is complete. */ export declare function update(ref: DatabaseReference, values: object): Promise<void>; /** * Gets the most up-to-date result for this query. * * @param query - The query to run. * @returns A `Promise` which resolves to the resulting DataSnapshot if a value is * available, or rejects if the client is unable to return a value (e.g., if the * server is unreachable and there is nothing cached). */ export declare function get(query: Query): Promise<DataSnapshot>; /** * Represents registration for 'value' events. */ export declare class ValueEventRegistration implements EventRegistration { private callbackContext; constructor(callbackContext: CallbackContext); respondsTo(eventType: string): boolean; createEvent(change: Change, query: QueryContext): DataEvent; getEventRunner(eventData: CancelEvent | DataEvent): () => void; createCancelEvent(error: Error, path: Path): CancelEvent | null; matches(other: EventRegistration): boolean; hasAnyCallback(): boolean; } /** * Represents the registration of a child_x event. */ export declare class ChildEventRegistration implements EventRegistration { private eventType; private callbackContext; constructor(eventType: string, callbackContext: CallbackContext | null); respondsTo(eventType: string): boolean; createCancelEvent(error: Error, path: Path): CancelEvent | null; createEvent(change: Change, query: QueryContext): DataEvent; getEventRunner(eventData: CancelEvent | DataEvent): () => void; matches(other: EventRegistration): boolean; hasAnyCallback(): boolean; } /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onValue` event will trigger once with the initial data stored at this * location, and then trigger again each time the data changes. The * `DataSnapshot` passed to the callback will be for the location at which * `on()` was called. It won't trigger until the entire contents has been * synchronized. If the location has no data, it will be triggered with an empty * `DataSnapshot` (`val()` will return `null`). * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. The * callback will be passed a DataSnapshot. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @returns A function that can be invoked to remove the listener. */ export declare function onValue(query: Query, callback: (snapshot: DataSnapshot) => unknown, cancelCallback?: (error: Error) => unknown): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onValue` event will trigger once with the initial data stored at this * location, and then trigger again each time the data changes. The * `DataSnapshot` passed to the callback will be for the location at which * `on()` was called. It won't trigger until the entire contents has been * synchronized. If the location has no data, it will be triggered with an empty * `DataSnapshot` (`val()` will return `null`). * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. The * callback will be passed a DataSnapshot. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onValue(query: Query, callback: (snapshot: DataSnapshot) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onValue` event will trigger once with the initial data stored at this * location, and then trigger again each time the data changes. The * `DataSnapshot` passed to the callback will be for the location at which * `on()` was called. It won't trigger until the entire contents has been * synchronized. If the location has no data, it will be triggered with an empty * `DataSnapshot` (`val()` will return `null`). * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. The * callback will be passed a DataSnapshot. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onValue(query: Query, callback: (snapshot: DataSnapshot) => unknown, cancelCallback: (error: Error) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildAdded` event will be triggered once for each initial child at this * location, and it will be triggered again every time a new child is added. The * `DataSnapshot` passed into the callback will reflect the data for the * relevant child. For ordering purposes, it is passed a second argument which * is a string containing the key of the previous sibling child by sort order, * or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @returns A function that can be invoked to remove the listener. */ export declare function onChildAdded(query: Query, callback: (snapshot: DataSnapshot, previousChildName?: string | null) => unknown, cancelCallback?: (error: Error) => unknown): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildAdded` event will be triggered once for each initial child at this * location, and it will be triggered again every time a new child is added. The * `DataSnapshot` passed into the callback will reflect the data for the * relevant child. For ordering purposes, it is passed a second argument which * is a string containing the key of the previous sibling child by sort order, * or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildAdded(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildAdded` event will be triggered once for each initial child at this * location, and it will be triggered again every time a new child is added. The * `DataSnapshot` passed into the callback will reflect the data for the * relevant child. For ordering purposes, it is passed a second argument which * is a string containing the key of the previous sibling child by sort order, * or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildAdded(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, cancelCallback: (error: Error) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildChanged` event will be triggered when the data stored in a child * (or any of its descendants) changes. Note that a single `child_changed` event * may represent multiple changes to the child. The `DataSnapshot` passed to the * callback will contain the new child contents. For ordering purposes, the * callback is also passed a second argument which is a string containing the * key of the previous sibling child by sort order, or `null` if it is the first * child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @returns A function that can be invoked to remove the listener. */ export declare function onChildChanged(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, cancelCallback?: (error: Error) => unknown): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildChanged` event will be triggered when the data stored in a child * (or any of its descendants) changes. Note that a single `child_changed` event * may represent multiple changes to the child. The `DataSnapshot` passed to the * callback will contain the new child contents. For ordering purposes, the * callback is also passed a second argument which is a string containing the * key of the previous sibling child by sort order, or `null` if it is the first * child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildChanged(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildChanged` event will be triggered when the data stored in a child * (or any of its descendants) changes. Note that a single `child_changed` event * may represent multiple changes to the child. The `DataSnapshot` passed to the * callback will contain the new child contents. For ordering purposes, the * callback is also passed a second argument which is a string containing the * key of the previous sibling child by sort order, or `null` if it is the first * child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildChanged(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, cancelCallback: (error: Error) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildMoved` event will be triggered when a child's sort order changes * such that its position relative to its siblings changes. The `DataSnapshot` * passed to the callback will be for the data of the child that has moved. It * is also passed a second argument which is a string containing the key of the * previous sibling child by sort order, or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @returns A function that can be invoked to remove the listener. */ export declare function onChildMoved(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, cancelCallback?: (error: Error) => unknown): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildMoved` event will be triggered when a child's sort order changes * such that its position relative to its siblings changes. The `DataSnapshot` * passed to the callback will be for the data of the child that has moved. It * is also passed a second argument which is a string containing the key of the * previous sibling child by sort order, or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildMoved(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildMoved` event will be triggered when a child's sort order changes * such that its position relative to its siblings changes. The `DataSnapshot` * passed to the callback will be for the data of the child that has moved. It * is also passed a second argument which is a string containing the key of the * previous sibling child by sort order, or `null` if it is the first child. * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildMoved(query: Query, callback: (snapshot: DataSnapshot, previousChildName: string | null) => unknown, cancelCallback: (error: Error) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildRemoved` event will be triggered once every time a child is * removed. The `DataSnapshot` passed into the callback will be the old data for * the child that was removed. A child will get removed when either: * * - a client explicitly calls `remove()` on that child or one of its ancestors * - a client calls `set(null)` on that child or one of its ancestors * - that child has all of its children removed * - there is a query in effect which now filters out the child (because it's * sort order changed or the max limit was hit) * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @returns A function that can be invoked to remove the listener. */ export declare function onChildRemoved(query: Query, callback: (snapshot: DataSnapshot) => unknown, cancelCallback?: (error: Error) => unknown): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildRemoved` event will be triggered once every time a child is * removed. The `DataSnapshot` passed into the callback will be the old data for * the child that was removed. A child will get removed when either: * * - a client explicitly calls `remove()` on that child or one of its ancestors * - a client calls `set(null)` on that child or one of its ancestors * - that child has all of its children removed * - there is a query in effect which now filters out the child (because it's * sort order changed or the max limit was hit) * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildRemoved(query: Query, callback: (snapshot: DataSnapshot) => unknown, options: ListenOptions): Unsubscribe; /** * Listens for data changes at a particular location. * * This is the primary way to read data from a Database. Your callback * will be triggered for the initial data and again whenever the data changes. * Invoke the returned unsubscribe callback to stop receiving updates. See * {@link https://firebase.google.com/docs/database/web/retrieve-data | Retrieve Data on the Web} * for more details. * * An `onChildRemoved` event will be triggered once every time a child is * removed. The `DataSnapshot` passed into the callback will be the old data for * the child that was removed. A child will get removed when either: * * - a client explicitly calls `remove()` on that child or one of its ancestors * - a client calls `set(null)` on that child or one of its ancestors * - that child has all of its children removed * - there is a query in effect which now filters out the child (because it's * sort order changed or the max limit was hit) * * @param query - The query to run. * @param callback - A callback that fires when the specified event occurs. * The callback will be passed a DataSnapshot and a string containing the key of * the previous child, by sort order, or `null` if it is the first child. * @param cancelCallback - An optional callback that will be notified if your * event subscription is ever canceled because your client does not have * permission to read this data (or it had permission but has now lost it). * This callback will be passed an `Error` object indicating why the failure * occurred. * @param options - An object that can be used to configure `onlyOnce`, which * then removes the listener after its first invocation. * @returns A function that can be invoked to remove the listener. */ export declare function onChildRemoved(query: Query, callback: (snapshot: DataSnapshot) => unknown, cancelCallback: (error: Error) => unknown, options: ListenOptions): Unsubscribe; export { EventType }; /** * Detaches a callback previously attached with `on()`. * * Detach a callback previously attached with `on()`. Note that if `on()` was * called multiple times with the same eventType and callback, the callback * will be called multiple times for each event, and `off()` must be called * multiple times to remove the callback. Calling `off()` on a parent listener * will not automatically remove listeners registered on child nodes, `off()` * must also be called on any child listeners to remove the callback. * * If a callback is not specified, all callbacks for the specified eventType * will be removed. Similarly, if no eventType is specified, all callbacks * for the `Reference` will be removed. * * Individual listeners can also be removed by invoking their unsubscribe * callbacks. * * @param query - The query that the listener was registered with. * @param eventType - One of the following strings: "value", "child_added", * "child_changed", "child_removed", or "child_moved." If omitted, all callbacks * for the `Reference` will be removed. * @param callback - The callback function that was passed to `on()` or * `undefined` to remove all callbacks. */ export declare function off(query: Query, eventType?: EventType, callback?: (snapshot: DataSnapshot, previousChildName?: string | null) => unknown): void; /** Describes the different query constraints available in this SDK. */ export declare type QueryConstraintType = 'endAt' | 'endBefore' | 'startAt' | 'startAfter' | 'limitToFirst' | 'limitToLast' | 'orderByChild' | 'orderByKey' | 'orderByPriority' | 'orderByValue' | 'equalTo'; /** * A `QueryConstraint` is used to narrow the set of documents returned by a * Database query. `QueryConstraint`s are created by invoking {@link endAt}, * {@link endBefore}, {@link startAt}, {@link startAfter}, {@link * limitToFirst}, {@link limitToLast}, {@link orderByChild}, * {@link orderByChild}, {@link orderByKey} , {@link orderByPriority} , * {@link orderByValue} or {@link equalTo} and * can then be passed to {@link query} to create a new query instance that * also contains this `QueryConstraint`. */ export declare abstract class QueryConstraint { /** The type of this query constraints */ abstract readonly type: QueryConstraintType; /** * Takes the provided `Query` and returns a copy of the `Query` with this * `QueryConstraint` applied. */ abstract _apply<T>(query: QueryImpl): QueryImpl; } /** * Creates a `QueryConstraint` with the specified ending point. * * Using `startAt()`, `startAfter()`, `endBefore()`, `endAt()` and `equalTo()` * allows you to choose arbitrary starting and ending points for your queries. * * The ending point is inclusive, so children with exactly the specified value * will be included in the query. The optional key argument can be used to * further limit the range of the query. If it is specified, then children that * have exactly the specified value must also have a key name less than or equal * to the specified key. * * You can read more about `endAt()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#filtering_data | Filtering data}. * * @param value - The value to end at. The argument type depends on which * `orderBy*()` function was used in this query. Specify a value that matches * the `orderBy*()` type. When used in combination with `orderByKey()`, the * value must be a string. * @param key - The child key to end at, among the children with the previously * specified priority. This argument is only allowed if ordering by child, * value, or priority. */ export declare function endAt(value: number | string | boolean | null, key?: string): QueryConstraint; /** * Creates a `QueryConstraint` with the specified ending point (exclusive). * * Using `startAt()`, `startAfter()`, `endBefore()`, `endAt()` and `equalTo()` * allows you to choose arbitrary starting and ending points for your queries. * * The ending point is exclusive. If only a value is provided, children * with a value less than the specified value will be included in the query. * If a key is specified, then children must have a value lesss than or equal * to the specified value and a a key name less than the specified key. * * @param value - The value to end before. The argument type depends on which * `orderBy*()` function was used in this query. Specify a value that matches * the `orderBy*()` type. When used in combination with `orderByKey()`, the * value must be a string. * @param key - The child key to end before, among the children with the * previously specified priority. This argument is only allowed if ordering by * child, value, or priority. */ export declare function endBefore(value: number | string | boolean | null, key?: string): QueryConstraint; /** * Creates a `QueryConstraint` with the specified starting point. * * Using `startAt()`, `startAfter()`, `endBefore()`, `endAt()` and `equalTo()` * allows you to choose arbitrary starting and ending points for your queries. * * The starting point is inclusive, so children with exactly the specified value * will be included in the query. The optional key argument can be used to * further limit the range of the query. If it is specified, then children that * have exactly the specified value must also have a key name greater than or * equal to the specified key. * * You can read more about `startAt()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#filtering_data | Filtering data}. * * @param value - The value to start at. The argument type depends on which * `orderBy*()` function was used in this query. Specify a value that matches * the `orderBy*()` type. When used in combination with `orderByKey()`, the * value must be a string. * @param key - The child key to start at. This argument is only allowed if * ordering by child, value, or priority. */ export declare function startAt(value?: number | string | boolean | null, key?: string): QueryConstraint; /** * Creates a `QueryConstraint` with the specified starting point (exclusive). * * Using `startAt()`, `startAfter()`, `endBefore()`, `endAt()` and `equalTo()` * allows you to choose arbitrary starting and ending points for your queries. * * The starting point is exclusive. If only a value is provided, children * with a value greater than the specified value will be included in the query. * If a key is specified, then children must have a value greater than or equal * to the specified value and a a key name greater than the specified key. * * @param value - The value to start after. The argument type depends on which * `orderBy*()` function was used in this query. Specify a value that matches * the `orderBy*()` type. When used in combination with `orderByKey()`, the * value must be a string. * @param key - The child key to start after. This argument is only allowed if * ordering by child, value, or priority. */ export declare function startAfter(value: number | string | boolean | null, key?: string): QueryConstraint; /** * Creates a new `QueryConstraint` that if limited to the first specific number * of children. * * The `limitToFirst()` method is used to set a maximum number of children to be * synced for a given callback. If we set a limit of 100, we will initially only * receive up to 100 `child_added` events. If we have fewer than 100 messages * stored in our Database, a `child_added` event will fire for each message. * However, if we have over 100 messages, we will only receive a `child_added` * event for the first 100 ordered messages. As items change, we will receive * `child_removed` events for each item that drops out of the active list so * that the total number stays at 100. * * You can read more about `limitToFirst()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#filtering_data | Filtering data}. * * @param limit - The maximum number of nodes to include in this query. */ export declare function limitToFirst(limit: number): QueryConstraint; /** * Creates a new `QueryConstraint` that is limited to return only the last * specified number of children. * * The `limitToLast()` method is used to set a maximum number of children to be * synced for a given callback. If we set a limit of 100, we will initially only * receive up to 100 `child_added` events. If we have fewer than 100 messages * stored in our Database, a `child_added` event will fire for each message. * However, if we have over 100 messages, we will only receive a `child_added` * event for the last 100 ordered messages. As items change, we will receive * `child_removed` events for each item that drops out of the active list so * that the total number stays at 100. * * You can read more about `limitToLast()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#filtering_data | Filtering data}. * * @param limit - The maximum number of nodes to include in this query. */ export declare function limitToLast(limit: number): QueryConstraint; /** * Creates a new `QueryConstraint` that orders by the specified child key. * * Queries can only order by one key at a time. Calling `orderByChild()` * multiple times on the same query is an error. * * Firebase queries allow you to order your data by any child key on the fly. * However, if you know in advance what your indexes will be, you can define * them via the .indexOn rule in your Security Rules for better performance. See * the{@link https://firebase.google.com/docs/database/security/indexing-data} * rule for more information. * * You can read more about `orderByChild()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#sort_data | Sort data}. * * @param path - The path to order by. */ export declare function orderByChild(path: string): QueryConstraint; /** * Creates a new `QueryConstraint` that orders by the key. * * Sorts the results of a query by their (ascending) key values. * * You can read more about `orderByKey()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#sort_data | Sort data}. */ export declare function orderByKey(): QueryConstraint; /** * Creates a new `QueryConstraint` that orders by priority. * * Applications need not use priority but can order collections by * ordinary properties (see * {@link https://firebase.google.com/docs/database/web/lists-of-data#sort_data | Sort data} * for alternatives to priority. */ export declare function orderByPriority(): QueryConstraint; /** * Creates a new `QueryConstraint` that orders by value. * * If the children of a query are all scalar values (string, number, or * boolean), you can order the results by their (ascending) values. * * You can read more about `orderByValue()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#sort_data | Sort data}. */ export declare function orderByValue(): QueryConstraint; /** * Creates a `QueryConstraint` that includes children that match the specified * value. * * Using `startAt()`, `startAfter()`, `endBefore()`, `endAt()` and `equalTo()` * allows you to choose arbitrary starting and ending points for your queries. * * The optional key argument can be used to further limit the range of the * query. If it is specified, then children that have exactly the specified * value must also have exactly the specified key as their key name. This can be * used to filter result sets with many matches for the same value. * * You can read more about `equalTo()` in * {@link https://firebase.google.com/docs/database/web/lists-of-data#filtering_data | Filtering data}. * * @param value - The value to match for. The argument type depends on which * `orderBy*()` function was used in this query. Specify a value that matches * the `orderBy*()` type. When used in combination with `orderByKey()`, the * value must be a string. * @param key - The child key to start at, among the children with the * previously specified priority. This argument is only allowed if ordering by * child, value, or priority. */ export declare function equalTo(value: number | string | boolean | null, key?: string): QueryConstraint; /** * Creates a new immutable instance of `Query` that is extended to also include * additional query constraints. * * @param query - The Query instance to use as a base for the new constraints. * @param queryConstraints - The list of `QueryConstraint`s to apply. * @throws if any of the provided query constraints cannot be combined with the * existing or new constraints. */ export declare function query(query: Query, ...queryConstraints: QueryConstraint[]): Query;
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