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musix-oss/node_modules/firebase/externs/firebase-database-externs.js
2020-03-03 22:30:50 +02:00

1683 lines
62 KiB
JavaScript

/**
* @license Copyright 2017 Google Inc.
*
* 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.
*/
/**
* @fileoverview Firebase Database API.
* @externs
*/
/**
* Gets the {@link firebase.database.Database `Database`} service for the
* default app or a given app.
*
* `firebase.database()` can be called with no arguments to access the default
* app's {@link firebase.database.Database `Database`} service or as
* `firebase.database(app)` to access the
* {@link firebase.database.Database `Database`} service associated with a
* specific app.
*
* `firebase.database` is also a namespace that can be used to access global
* constants and methods associated with the `Database` service.
*
* @example
* // Get the Database service for the default app
* var defaultDatabase = firebase.database();
*
* @example
* // Get the Database service for a specific app
* var otherDatabase = firebase.database(app);
*
* @namespace
* @param {!firebase.app.App=} app Optional app whose Database service to
* return. If not provided, the default Database service will be returned.
* @return {!firebase.database.Database} The default Database service if no app
* is provided or the Database service associated with the provided app.
*/
firebase.database = function(app) {};
/**
* Gets the {@link firebase.database.Database `Database`} service for the
* current app.
*
* @example
* var database = app.database();
* // The above is shorthand for:
* // var database = firebase.database(app);
*
* @return {!firebase.database.Database}
*/
firebase.app.App.prototype.database = function() {};
/**
* The Firebase Database service interface.
*
* Do not call this constructor directly. Instead, use
* {@link firebase.database `firebase.database()`}.
*
* See
* {@link
* https://firebase.google.com/docs/database/web/start/
* Installation & Setup in JavaScript}
* for a full guide on how to use the Firebase Database service.
*
* @interface
*/
firebase.database.Database = function() {};
/**
* Logs debugging information to the console.
*
* @example
* // Enable logging
* firebase.database.enableLogging(true);
*
* @example
* // Disable logging
* firebase.database.enableLogging(false);
*
* @example
* // Enable logging across page refreshes
* firebase.database.enableLogging(true, true);
*
* @example
* // Provide custom logger which prefixes log statements with "[FIREBASE]"
* firebase.database.enableLogging(function(message) {
* console.log("[FIREBASE]", message);
* });
*
* @param {(boolean|function(string))=} logger Enables logging if `true`;
* disables logging if `false`. You can also provide a custom logger function
* to control how things get logged.
* @param {boolean=} persistent Remembers the logging state between page
* refreshes if `true`.
*/
firebase.database.enableLogging = function(logger, persistent) {};
/**
* @namespace
*/
firebase.database.ServerValue = {};
/**
* A placeholder value for auto-populating the current timestamp (time
* since the Unix epoch, in milliseconds) as determined by the Firebase
* servers.
*
* @example
* var sessionsRef = firebase.database().ref("sessions");
* sessionsRef.push({
* startedAt: firebase.database.ServerValue.TIMESTAMP
* });
*
* @const {!Object}
*/
firebase.database.ServerValue.TIMESTAMP;
/**
* The {@link firebase.app.App app} associated with the `Database` service
* instance.
*
* @example
* var app = database.app;
*
* @type {!firebase.app.App}
*/
firebase.database.Database.prototype.app;
/**
* 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.
*
* @example
* // Get a reference to the root of the Database
* var rootRef = firebase.database().ref();
*
* @example
* // Get a reference to the /users/ada node
* var adaRef = firebase.database().ref("users/ada");
* // The above is shorthand for the following operations:
* //var rootRef = firebase.database().ref();
* //var adaRef = rootRef.child("users/ada");
*
* @param {string=} 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.
* @return {!firebase.database.Reference} If a path is provided, a `Reference`
* pointing to the provided path. Otherwise, a `Reference` pointing to the
* root of the Database.
*/
firebase.database.Database.prototype.ref = function(path) {};
/**
* 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`.
*
* @example
* // Get a reference to the root of the Database
* var rootRef = firebase.database().ref("https://<DATABASE_NAME>.firebaseio.com");
*
* @example
* // Get a reference to the /users/ada node
* var adaRef = firebase.database().ref("https://<DATABASE_NAME>.firebaseio.com/users/ada");
*
* @param {string} url The Firebase URL at which the returned `Reference` will
* point.
* @return {!firebase.database.Reference} A `Reference` pointing to the provided
* Firebase URL.
*/
firebase.database.Database.prototype.refFromURL = function(url) {};
/**
* Disconnects from the server (all Database operations will be completed
* offline).
*
* The client automatically maintains a persistent connection to the Database
* server, which will remain active indefinitely and reconnect when
* disconnected. However, the `goOffline()` and `goOnline()` methods may be used
* to control the client connection in cases where a persistent connection is
* undesirable.
*
* While offline, the client will no longer receive data updates from the
* Database. However, all Database operations performed locally will continue to
* immediately fire events, allowing your application to continue behaving
* normally. Additionally, each operation performed locally will automatically
* be queued and retried upon reconnection to the Database server.
*
* To reconnect to the Database and begin receiving remote events, see
* `goOnline()`.
*
* @example
* firebase.database().goOffline();
*/
firebase.database.Database.prototype.goOffline = function() {};
/**
* Reconnects to the server and synchronizes the offline Database state
* with the server state.
*
* This method should be used after disabling the active connection with
* `goOffline()`. Once reconnected, the client will transmit the proper data
* and fire the appropriate events so that your client "catches up"
* automatically.
*
* @example
* firebase.database().goOnline();
*/
firebase.database.Database.prototype.goOnline = function() {};
/**
* A `Reference` represents a specific location in your Database and can be used
* for reading or writing data to that Database location.
*
* You can reference the root or child location in your Database by calling
* `firebase.database().ref()` or `firebase.database().ref("child/path")`.
*
* Writing is done with the `set()` method and reading can be done with the
* `on()` method. See
* {@link
* https://firebase.google.com/docs/database/web/read-and-write
* Read and Write Data on the Web}
*
* @interface
* @extends {firebase.database.Query}
*/
firebase.database.Reference = function() {};
/**
* The last part of the `Reference`'s path.
*
* For example, `"ada"` is the key for
* `https://<DATABASE_NAME>.firebaseio.com/users/ada`.
*
* The key of a root `Reference` is `null`.
*
* @example
* // The key of a root reference is null
* var rootRef = firebase.database().ref();
* var key = rootRef.key; // key === null
*
* @example
* // The key of any non-root reference is the last token in the path
* var adaRef = firebase.database().ref("users/ada");
* var key = adaRef.key; // key === "ada"
* key = adaRef.child("name/last").key; // key === "last"
*
* @type {string|null}
*/
firebase.database.Reference.prototype.key;
/**
* 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").
*
* @example
* var usersRef = firebase.database().ref('users');
* var adaRef = usersRef.child('ada');
* var adaFirstNameRef = adaRef.child('name/first');
* var path = adaFirstNameRef.toString();
* // path is now 'https://sample-app.firebaseio.com/users/ada/name/first'
*
* @param {string} path A relative path from this location to the desired child
* location.
* @return {!firebase.database.Reference} The specified child location.
*/
firebase.database.Reference.prototype.child = function(path) {};
/**
* The parent location of a `Reference`.
*
* The parent of a root `Reference` is `null`.
*
* @example
* // The parent of a root reference is null
* var rootRef = firebase.database().ref();
* parent = rootRef.parent; // parent === null
*
* @example
* // The parent of any non-root reference is the parent location
* var usersRef = firebase.database().ref("users");
* var adaRef = firebase.database().ref("users/ada");
* // usersRef and adaRef.parent represent the same location
*
* @type {?firebase.database.Reference}
*/
firebase.database.Reference.prototype.parent;
/**
* The root `Reference` of the Database.
*
* @example
* // The root of a root reference is itself
* var rootRef = firebase.database().ref();
* // rootRef and rootRef.root represent the same location
*
* @example
* // The root of any non-root reference is the root location
* var adaRef = firebase.database().ref("users/ada");
* // rootRef and adaRef.root represent the same location
*
* @type {!firebase.database.Reference}
*/
firebase.database.Reference.prototype.root;
/**
* @type {string}
*/
firebase.database.Reference.prototype.path;
/**
* 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.
*
* @example
* var adaNameRef = firebase.database().ref('users/ada/name');
* adaNameRef.child('first').set('Ada');
* adaNameRef.child('last').set('Lovelace');
* // We've written 'Ada' to the Database location storing Ada's first name,
* // and 'Lovelace' to the location storing her last name.
*
* @example
* adaNameRef.set({ first: 'Ada', last: 'Lovelace' });
* // Exact same effect as the previous example, except we've written
* // Ada's first and last name simultaneously.
*
* @example
* adaNameRef.set({ first: 'Ada', last: 'Lovelace' })
* .then(function() {
* console.log('Synchronization succeeded');
* })
* .catch(function(error) {
* console.log('Synchronization failed');
* });
* // Same as the previous example, except we will also log a message
* // when the data has finished synchronizing.
*
* @param {*} value The value to be written (string, number, boolean, object,
* array, or null).
* @param {function(?Error)=} onComplete Callback called when write to server is
* complete.
* @return {!firebase.Promise<void>} Resolves when write to server is complete.
*/
firebase.database.Reference.prototype.set = function(value, onComplete) {};
/**
* 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}.
*
* @example
* var adaNameRef = firebase.database().ref('users/ada/name');
* // Modify the 'first' and 'last' properties, but leave other data at
* // adaNameRef unchanged.
* adaNameRef.update({ first: 'Ada', last: 'Lovelace' });
*
* @param {!Object} values Object containing multiple values.
* @param {function(?Error)=} onComplete Callback called when write to server is
* complete.
* @return {!firebase.Promise<void>} Resolves when update on server is complete.
*/
firebase.database.Reference.prototype.update = function(values, onComplete) {};
/**
* 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 {*} newVal
* @param {string|number|null} newPriority
* @param {function(?Error)=} onComplete
* @return {!firebase.Promise<void>}
*/
firebase.database.Reference.prototype.setWithPriority = function(
newVal,
newPriority,
onComplete
) {};
/**
* 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.
*
* @example
* var adaRef = firebase.database().ref('users/ada');
* adaRef.remove()
* .then(function() {
* console.log("Remove succeeded.")
* })
* .catch(function(error) {
* console.log("Remove failed: " + error.message)
* });
*
* @param {function(?Error)=} onComplete Callback called when write to server is
* complete.
* @return {!firebase.Promise<void>} Resolves when remove on server is complete.
*/
firebase.database.Reference.prototype.remove = function(onComplete) {};
/**
* Atomically modifies the data at this location.
*
* Atomically modify the data at this location. Unlike a normal `set()`, which
* just overwrites the data regardless of its previous value, `transaction()` is
* used to modify the existing value to a new value, ensuring there are no
* conflicts with other clients writing to the same location at the same time.
*
* To accomplish this, you pass `transaction()` an update function which is used
* to transform the current value into a new value. If another client writes to
* the location before your new value is successfully written, your update
* function will be called again with the new current value, and the write will
* be retried. This will happen repeatedly until your write succeeds without
* conflict or you abort the transaction by not returning a value from your
* update function.
*
* Note: Modifying data with `set()` will cancel any pending transactions at
* that location, so extreme care should be taken if mixing `set()` and
* `transaction()` to update the same data.
*
* Note: When using transactions with Security and Firebase Rules in place, be
* aware that a client needs `.read` access in addition to `.write` access in
* order to perform a transaction. This is because the client-side nature of
* transactions requires the client to read the data in order to transactionally
* update it.
*
* @example
* // Increment Ada's rank by 1.
* var adaRankRef = firebase.database().ref('users/ada/rank');
* adaRankRef.transaction(function(currentRank) {
* // If users/ada/rank has never been set, currentRank will be `null`.
* return currentRank + 1;
* });
*
* @example
* // Try to create a user for ada, but only if the user id 'ada' isn't
* // already taken
* var adaRef = firebase.database().ref('users/ada');
* adaRef.transaction(function(currentData) {
* if (currentData === null) {
* return { name: { first: 'Ada', last: 'Lovelace' } };
* } else {
* console.log('User ada already exists.');
* return; // Abort the transaction.
* }
* }, function(error, committed, snapshot) {
* if (error) {
* console.log('Transaction failed abnormally!', error);
* } else if (!committed) {
* console.log('We aborted the transaction (because ada already exists).');
* } else {
* console.log('User ada added!');
* }
* console.log("Ada's data: ", snapshot.val());
* });
*
*
* @param {function(*): *} transactionUpdate A developer-supplied function which
* will be passed the current data stored at this location (as a JavaScript
* object). The function should return the new value it would like written (as
* a JavaScript object). If `undefined` is returned (i.e. you return with no
* arguments) the transaction will be aborted and the data at this location
* will not be modified.
* @param {(function(?Error, boolean,
* ?firebase.database.DataSnapshot))=} onComplete A callback
* function that will be called when the transaction completes. The callback
* is passed three arguments: a possibly-null `Error`, a `boolean` indicating
* whether the transaction was committed, and a `DataSnapshot` indicating the
* final result. If the transaction failed abnormally, the first argument will
* be an `Error` object indicating the failure cause. If the transaction
* finished normally, but no data was committed because no data was returned
* from `transactionUpdate`, then second argument will be false. If the
* transaction completed and committed data to Firebase, the second argument
* will be true. Regardless, the third argument will be a `DataSnapshot`
* containing the resulting data in this location.
* @param {boolean=} applyLocally By default, events are raised each time the
* transaction update function runs. So if it is run multiple times, you may
* see intermediate states. You can set this to false to suppress these
* intermediate states and instead wait until the transaction has completed
* before events are raised.
* @return {!firebase.Promise<{
* committed: boolean,
* snapshot: ?firebase.database.DataSnapshot
* }>} Returns a Promise that can optionally be used instead of the onComplete
* callback to handle success and failure.
*/
firebase.database.Reference.prototype.transaction = function(
transactionUpdate,
onComplete,
applyLocally
) {};
/**
* 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 {string|number|null} priority
* @param {function(?Error)} onComplete
* @return {!firebase.Promise<void>}
*/
firebase.database.Reference.prototype.setPriority = function(
priority,
onComplete
) {};
/**
* @interface
* @extends {firebase.database.Reference}
* @extends {firebase.Thenable<void>}
*/
firebase.database.ThenableReference = function() {};
/**
* 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 will be written to the
* generated location. If you don't pass a value, nothing will be written to the
* Database and the child will remain empty (but you can use the `Reference`
* elsewhere).
*
* The unique key generated by `push()` are ordered by the current time, so the
* resulting list of items will be 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
* https://firebase.googleblog.com/2015/02/the-2120-ways-to-ensure-unique_68.html
* The 2^120 Ways to Ensure Unique Identifiers}
*
* @example
* var messageListRef = firebase.database().ref('message_list');
* var newMessageRef = messageListRef.push();
* newMessageRef.set({
* 'user_id': 'ada',
* 'text': 'The Analytical Engine weaves algebraical patterns just as the Jacquard loom weaves flowers and leaves.'
* });
* // We've appended a new message to the message_list location.
* var path = newMessageRef.toString();
* // path will be something like
* // 'https://sample-app.firebaseio.com/message_list/-IKo28nwJLH0Nc5XeFmj'
*
* @param {*=} value Optional value to be written at the generated location.
* @param {function(?Error)=} onComplete Callback called when write to server is
* complete.
* @return {!firebase.database.ThenableReference} Combined `Promise` and
* `Reference`; resolves when write is complete, but can be used immediately
* as the `Reference` to the child location.
*/
firebase.database.Reference.prototype.push = function(value, onComplete) {};
/**
* 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.
*
* @return {!firebase.database.OnDisconnect}
*/
firebase.database.Reference.prototype.onDisconnect = function() {};
/**
* A `Query` sorts and filters the data at a Database location so only a subset
* of the child data is included. This can be used to order a collection of
* data by some attribute (for example, height of dinosaurs) as well as to
* restrict a large list of items (for example, chat messages) down to a number
* suitable for synchronizing to the client. Queries are created by chaining
* together one or more of the filter methods defined here.
*
* Just as with a `Reference`, you can receive data from a `Query` by using the
* `on()` method. You will only receive events and `DataSnapshot`s for the
* subset of the data that matches your query.
*
* Read our documentation on
* {@link
* https://firebase.google.com/docs/database/web/lists-of-data#sorting_and_filtering_data
* Sorting and filtering data} for more information.
*
* @interface
*/
firebase.database.Query = function() {};
/**
* Returns a `Reference` to the `Query`'s location.
*
* @type {!firebase.database.Reference}
*/
firebase.database.Query.prototype.ref;
/**
* Returns whether or not the current and provided queries represent the same
* location, have the same query parameters, and are from the same instance of
* `firebase.app.App`.
*
* Two `Reference` objects are equivalent if they represent the same location
* and are from the same instance of `firebase.app.App`.
*
* Two `Query` objects are equivalent if they represent the same location, have
* the same query parameters, and are from the same instance of
* `firebase.app.App`. Equivalent queries share the same sort order, limits, and
* starting and ending points.
*
* @example
* var rootRef = firebase.database.ref();
* var usersRef = rootRef.child("users");
*
* usersRef.isEqual(rootRef); // false
* usersRef.isEqual(rootRef.child("users")); // true
* usersRef.parent.isEqual(rootRef); // true
*
* @example
* var rootRef = firebase.database.ref();
* var usersRef = rootRef.child("users");
* var usersQuery = usersRef.limitToLast(10);
*
* usersQuery.isEqual(usersRef); // false
* usersQuery.isEqual(usersRef.limitToLast(10)); // true
* usersQuery.isEqual(rootRef.limitToLast(10)); // false
* usersQuery.isEqual(usersRef.orderByKey().limitToLast(10)); // false
*
* @param {firebase.database.Query} other The query to compare against.
* @return {boolean} Whether or not the current and provided queries are
* equivalent.
*/
firebase.database.Query.prototype.isEqual = function(other) {};
/**
* 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.
* Use `off( )` to stop receiving updates. See
* {@link https://firebase.google.com/docs/database/web/retrieve-data
* Retrieve Data on the Web}
* for more details.
*
* <h4>value event</h4>
*
* This 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`).
*
* <h4>child_added event</h4>
*
* This 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.
*
* <h4>child_removed event</h4>
*
* This 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)
*
* <h4>child_changed event</h4>
*
* This 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.
*
* <h4>child_moved event</h4>
*
* This 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.
*
* @example <caption>Handle a new value:</caption>
* ref.on('value', function(dataSnapshot) {
* ...
* });
*
* @example <caption>Handle a new child:</caption>
* ref.on('child_added', function(childSnapshot, prevChildKey) {
* ...
* });
*
* @example <caption>Handle child removal:</caption>
* ref.on('child_removed', function(oldChildSnapshot) {
* ...
* });
*
* @example <caption>Handle child data changes:</caption>
* ref.on('child_changed', function(childSnapshot, prevChildKey) {
* ...
* });
*
* @example <caption>Handle child ordering changes:</caption>
* ref.on('child_moved', function(childSnapshot, prevChildKey) {
* ...
* });
*
* @param {string} eventType One of the following strings: "value",
* "child_added", "child_changed", "child_removed", or "child_moved."
* @param {!function(firebase.database.DataSnapshot, string=)} callback A
* callback that fires when the specified event occurs. The callback will be
* passed a DataSnapshot. For ordering purposes, "child_added",
* "child_changed", and "child_moved" will also be passed a string containing
* the key of the previous child, by sort order, or `null` if it is the
* first child.
* @param {(function(Error)|Object)=} cancelCallbackOrContext 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 {Object=} context If provided, this object will be used as `this`
* when calling your callback(s).
* @return {!function(firebase.database.DataSnapshot, string=)} The provided
* callback function is returned unmodified. This is just for convenience if
* you want to pass an inline function to `on()` but store the callback
* function for later passing to `off()`.
*/
firebase.database.Query.prototype.on = function(
eventType,
callback,
cancelCallbackOrContext,
context
) {};
/**
* 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 or callback is specified, all
* callbacks for the `Reference` will be removed.
*
* @example
* var onValueChange = function(dataSnapshot) { ... };
* ref.on('value', onValueChange);
* ref.child('meta-data').on('child_added', onChildAdded);
* // Sometime later...
* ref.off('value', onValueChange);
*
* // You must also call off() for any child listeners on ref
* // to cancel those callbacks
* ref.child('meta-data').off('child_added', onValueAdded);
*
* @example
* // Or you can save a line of code by using an inline function
* // and on()'s return value.
* var onValueChange = ref.on('value', function(dataSnapshot) { ... });
* // Sometime later...
* ref.off('value', onValueChange);
*
* @param {string=} eventType One of the following strings: "value",
* "child_added", "child_changed", "child_removed", or "child_moved."
* @param {function(!firebase.database.DataSnapshot, ?string=)=} callback The
* callback function that was passed to `on()`.
* @param {Object=} context The context that was passed to `on()`.
*/
firebase.database.Query.prototype.off = function(
eventType,
callback,
context
) {};
/**
* Listens for exactly one event of the specified event type, and then stops
* listening.
*
* This is equivalent to calling {@link firebase.database.Query#on `on()`}, and
* then calling {@link firebase.database.Query#off `off()`} inside the callback
* function. See {@link firebase.database.Query#on `on()`} for details on the
* event types.
*
* @example
* // Basic usage of .once() to read the data located at ref.
* ref.once('value')
* .then(function(dataSnapshot) {
* // handle read data.
* });
*
* @param {string} eventType One of the following strings: "value",
* "child_added", "child_changed", "child_removed", or "child_moved."
* @param {function(!firebase.database.DataSnapshot, string=)=} successCallback A
* callback that fires when the specified event occurs. The callback will be
* passed a DataSnapshot. For ordering purposes, "child_added",
* "child_changed", and "child_moved" will also be passed a string containing
* the key of the previous child by sort order, or `null` if it is the
* first child.
* @param {(function(Error)|Object)=} failureCallbackOrContext An optional
* callback that will be notified if your client does not have permission to
* read the data. This callback will be passed an `Error` object indicating
* why the failure occurred.
* @param {Object=} context If provided, this object will be used as `this`
* when calling your callback(s).
* @return {!firebase.Promise<*>}
*/
firebase.database.Query.prototype.once = function(
eventType,
successCallback,
failureCallbackOrContext,
context
) {};
/**
* Generates a new `Query` 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}.
*
* @example
* // Find the two shortest dinosaurs.
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByChild("height").limitToFirst(2).on("child_added", function(snapshot) {
* // This will be called exactly two times (unless there are less than two
* // dinosaurs in the Database).
*
* // It will also get fired again if one of the first two dinosaurs is
* // removed from the data set, as a new dinosaur will now be the second
* // shortest.
* console.log(snapshot.key);
* });
*
* @param {number} limit The maximum number of nodes to include in this query.
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.limitToFirst = function(limit) {};
/**
* Generates a new `Query` object limited to the last specific 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}.
*
* @example
* // Find the two heaviest dinosaurs.
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByChild("weight").limitToLast(2).on("child_added", function(snapshot) {
* // This callback will be triggered exactly two times, unless there are
* // fewer than two dinosaurs stored in the Database. It will also get fired
* // for every new, heavier dinosaur that gets added to the data set.
* console.log(snapshot.key);
* });
*
* @param {number} limit The maximum number of nodes to include in this query.
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.limitToLast = function(limit) {};
/**
* Generates a new `Query` object ordered 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
* .indexOn} 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}.
*
* @example
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByChild("height").on("child_added", function(snapshot) {
* console.log(snapshot.key + " was " + snapshot.val().height + " m tall");
* });
*
* @param {string} path
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.orderByChild = function(path) {};
/**
* Generates a new `Query` object ordered by 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}.
*
* @example
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByKey().on("child_added", function(snapshot) {
* console.log(snapshot.key);
* });
*
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.orderByKey = function() {};
/**
* Generates a new `Query` object ordered 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.
*
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.orderByPriority = function() {};
/**
* Generates a new `Query` object ordered 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}.
*
* @example
* var scoresRef = firebase.database().ref("scores");
* scoresRef.orderByValue().limitToLast(3).on("value", function(snapshot) {
* snapshot.forEach(function(data) {
* console.log("The " + data.key + " score is " + data.val());
* });
* });
*
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.orderByValue = function() {};
/**
* Creates a `Query` with the specified starting point.
*
* Using `startAt()`, `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}.
*
* @example
* // Find all dinosaurs that are at least three meters tall.
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByChild("height").startAt(3).on("child_added", function(snapshot) {
* console.log(snapshot.key)
* });
*
* @param {number|string|boolean|null} 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 {string=} key The child key to start at. This argument is only allowed
* if ordering by child, value, or priority.
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.startAt = function(value, key) {};
/**
* Creates a `Query` with the specified ending point.
*
* Using `startAt()`, `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}.
*
* @example
* // Find all dinosaurs whose names come before Pterodactyl lexicographically.
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByKey().endAt("pterodactyl").on("child_added", function(snapshot) {
* console.log(snapshot.key);
* });
*
* @param {number|string|boolean|null} 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 {string=} 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.
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.endAt = function(value, key) {};
/**
* Creates a `Query` that includes children that match the specified value.
*
* Using `startAt()`, `endAt()`, and `equalTo()` allows us to choose arbitrary
* starting and ending points for our 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}.
*
* @example
* // Find all dinosaurs whose height is exactly 25 meters.
* var ref = firebase.database().ref("dinosaurs");
* ref.orderByChild("height").equalTo(25).on("child_added", function(snapshot) {
* console.log(snapshot.key);
* });
*
* @param {number|string|boolean|null} 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 {string=} 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.
* @return {!firebase.database.Query}
*/
firebase.database.Query.prototype.equalTo = function(value, key) {};
/**
* Gets the absolute URL for this location.
*
* The `toString()` method returns a URL that is ready to be put into a browser,
* curl command, or a `firebase.database().refFromURL()` call. Since all of
* those expect the URL to be url-encoded, `toString()` returns an encoded URL.
*
* Append '.json' to the returned URL when typed into a browser to download
* JSON-formatted data. If the location is secured (that is, not publicly
* readable), you will get a permission-denied error.
*
* @example
* // Calling toString() on a root Firebase reference returns the URL where its
* // data is stored within the Database:
* var rootRef = firebase.database().ref();
* var rootUrl = rootRef.toString();
* // rootUrl === "https://sample-app.firebaseio.com/".
*
* // Calling toString() at a deeper Firebase reference returns the URL of that
* // deep path within the Database:
* var adaRef = rootRef.child('users/ada');
* var adaURL = adaRef.toString();
* // adaURL === "https://sample-app.firebaseio.com/users/ada".
*
* @return {string} The absolute URL for this location.
* @override
*/
firebase.database.Query.prototype.toString = function() {};
/**
* Returns a JSON-serializable representation of this object.
*
* @return {!Object} A JSON-serializable representation of this object.
*/
firebase.database.Query.prototype.toJSON = function() {};
/**
* 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).
*
* @interface
*/
firebase.database.DataSnapshot = function() {};
/**
* 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).
*
* @example
* // Write and then read back a string from the Database.
* ref.set("hello")
* .then(function() {
* return ref.once("value");
* })
* .then(function(snapshot) {
* var data = snapshot.val(); // data === "hello"
* });
*
* @example
* // Write and then read back a JavaScript object from the Database.
* ref.set({ name: "Ada", age: 36 })
* .then(function() {
* return ref.once("value");
* })
* .then(function(snapshot) {
* var data = snapshot.val();
* // data is { "name": "Ada", "age": 36 }
* // data.name === "Ada"
* // data.age === 36
* });
*
* @return {*} The DataSnapshot's contents as a JavaScript value (Object,
* Array, string, number, boolean, or `null`).
*/
firebase.database.DataSnapshot.prototype.val = function() {};
/**
* 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.
*
* @return {*} The DataSnapshot's contents as a JavaScript value (Object,
* Array, string, number, boolean, or `null`).
*/
firebase.database.DataSnapshot.prototype.exportVal = function() {};
/**
* Returns true if this `DataSnapshot` contains any data. It is slightly more
* efficient than using `snapshot.val() !== null`.
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* // Test for the existence of certain keys within a DataSnapshot
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var a = snapshot.exists(); // true
* var b = snapshot.child("name").exists(); // true
* var c = snapshot.child("name/first").exists(); // true
* var d = snapshot.child("name/middle").exists(); // false
* });
*
* @return {boolean}
*/
firebase.database.DataSnapshot.prototype.exists = function() {};
/**
* 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.
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* // Test for the existence of certain keys within a DataSnapshot
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var name = snapshot.child("name").val(); // {first:"Ada",last:"Lovelace"}
* var firstName = snapshot.child("name/first").val(); // "Ada"
* var lastName = snapshot.child("name").child("last").val(); // "Lovelace"
* var age = snapshot.child("age").val(); // null
* });
*
* @param {string} path A relative path to the location of child data.
* @return {!firebase.database.DataSnapshot}
*/
firebase.database.DataSnapshot.prototype.child = function(path) {};
/**
* Returns true if the specified child path has (non-null) data.
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* // Determine which child keys in DataSnapshot have data.
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var hasName = snapshot.hasChild("name"); // true
* var hasAge = snapshot.hasChild("age"); // false
* });
*
* @param {string} path A relative path to the location of a potential child.
* @return {boolean} `true` if data exists at the specified child path; else
* `false`.
*/
firebase.database.DataSnapshot.prototype.hasChild = function(path) {};
/**
* 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}).
*
* @return {string|number|null}
*/
firebase.database.DataSnapshot.prototype.getPriority = function() {};
/**
* 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 `child_added` 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).
*
* @example
*
* // Assume we have the following data in the Database:
* {
* "users": {
* "ada": {
* "first": "Ada",
* "last": "Lovelace"
* },
* "alan": {
* "first": "Alan",
* "last": "Turing"
* }
* }
* }
*
* // Loop through users in order with the forEach() method. The callback
* // provided to forEach() will be called synchronously with a DataSnapshot
* // for each child:
* var query = firebase.database().ref("users").orderByKey();
* query.once("value")
* .then(function(snapshot) {
* snapshot.forEach(function(childSnapshot) {
* // key will be "ada" the first time and "alan" the second time
* var key = childSnapshot.key;
* // childData will be the actual contents of the child
* var childData = childSnapshot.val();
* });
* });
*
* @example
* // You can cancel the enumeration at any point by having your callback
* // function return true. For example, the following code sample will only
* // fire the callback function one time:
* var query = firebase.database().ref("users").orderByKey();
* query.once("value")
* .then(function(snapshot) {
* snapshot.forEach(function(childSnapshot) {
* var key = childSnapshot.key; // "ada"
*
* // Cancel enumeration
* return true;
* });
* });
*
* @param {function(!firebase.database.DataSnapshot): boolean} action A function
* that will be called for each child DataSnapshot. The callback can return
* true to cancel further enumeration.
* @return {boolean} true if enumeration was canceled due to your callback
* returning true.
*/
firebase.database.DataSnapshot.prototype.forEach = function(action) {};
/**
* 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`).
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var a = snapshot.hasChildren(); // true
* var b = snapshot.child("name").hasChildren(); // true
* var c = snapshot.child("name/first").hasChildren(); // false
* });
*
* @return {boolean} true if this snapshot has any children; else false.
*/
firebase.database.DataSnapshot.prototype.hasChildren = function() {};
/**
* 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`.
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var key = snapshot.key; // "ada"
* var childKey = snapshot.child("name/last").key; // "last"
* });
*
* @example
* var rootRef = firebase.database().ref();
* rootRef.once("value")
* .then(function(snapshot) {
* var key = snapshot.key; // null
* var childKey = snapshot.child("users/ada").key; // "ada"
* });
*
* @type {string|null}
*/
firebase.database.DataSnapshot.prototype.key;
/**
* Returns the number of child properties of this `DataSnapshot`.
*
* @example
* // Assume we have the following data in the Database:
* {
* "name": {
* "first": "Ada",
* "last": "Lovelace"
* }
* }
*
* var ref = firebase.database().ref("users/ada");
* ref.once("value")
* .then(function(snapshot) {
* var a = snapshot.numChildren(); // 1 ("name")
* var b = snapshot.child("name").numChildren(); // 2 ("first", "last")
* var c = snapshot.child("name/first").numChildren(); // 0
* });
*
* @return {number}
*/
firebase.database.DataSnapshot.prototype.numChildren = function() {};
/**
* The `Reference` for the location that generated this `DataSnapshot`.
*
* @type {!firebase.database.Reference}
*/
firebase.database.DataSnapshot.prototype.ref;
/**
* Returns a JSON-serializable representation of this object.
*
* @return {?Object} A JSON-serializable representation of this object.
*/
firebase.database.DataSnapshot.prototype.toJSON = function() {};
/**
* The `onDisconnect` class allows you to write or clear data when your client
* disconnects from the Database server. These updates occur whether your
* client disconnects cleanly or not, so you can rely on them to clean up data
* even if a connection is dropped or a client crashes.
*
* The `onDisconnect` class is most commonly used to manage presence in
* applications where it is useful to detect how many clients are connected and
* when other clients disconnect. See
* {@link
* https://firebase.google.com/docs/database/web/offline-capabilities
* Enabling Offline Capabilities in JavaScript} for more information.
*
* To avoid problems when a connection is dropped before the requests can be
* transferred to the Database server, these functions should be called before
* writing any data.
*
* Note that `onDisconnect` operations are only triggered once. If you want an
* operation to occur each time a disconnect occurs, you'll need to re-establish
* the `onDisconnect` operations each time you reconnect.
*
* @interface
*/
firebase.database.OnDisconnect = function() {};
/**
* Cancels all previously queued `onDisconnect()` set or update events for this
* location and all children.
*
* If a write has been queued for this location via a `set()` or `update()` at a
* parent location, the write at this location will be canceled, though writes
* to sibling locations will still occur.
*
* @example
* var ref = firebase.database().ref("onlineState");
* ref.onDisconnect().set(false);
* // ... sometime later
* ref.onDisconnect().cancel();
*
* @param {function(?Error)=} onComplete An optional callback function that will
* be called when synchronization to the server has completed. The callback
* will be passed a single parameter: null for success, or an Error object
* indicating a failure.
* @return {!firebase.Promise<void>} Resolves when synchronization to the server
* is complete.
*/
firebase.database.OnDisconnect.prototype.cancel = function(onComplete) {};
/**
* Ensures the data at this location is deleted when the client is disconnected
* (due to closing the browser, navigating to a new page, or network issues).
*
* @param {function(?Error)=} onComplete An optional callback function that will
* be called when synchronization to the server has completed. The callback
* will be passed a single parameter: null for success, or an Error object
* indicating a failure.
* @return {!firebase.Promise<void>} Resolves when synchronization to the server
* is complete.
*/
firebase.database.OnDisconnect.prototype.remove = function(onComplete) {};
/**
* Ensures 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).
*
* `set()` 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. See
* {@link
* https://firebase.google.com/docs/database/web/offline-capabilities
* Enabling Offline Capabilities in JavaScript} for more information.
*
* Note that `onDisconnect` operations are only triggered once. If you want an
* operation to occur each time a disconnect occurs, you'll need to re-establish
* the `onDisconnect` operations each time.
*
* @example
* var ref = firebase.database().ref("users/ada/status");
* ref.onDisconnect().set("I disconnected!");
*
* @param {*} value The value to be written to this location on
* disconnect (can be an object, array, string, number, boolean, or null).
* @param {function(?Error)=} onComplete An optional callback function that
* will be called when synchronization to the Database server has completed.
* The callback will be passed a single parameter: null for success, or an
* `Error` object indicating a failure.
* @return {!firebase.Promise<void>} Resolves when synchronization to the
* Database is complete.
*/
firebase.database.OnDisconnect.prototype.set = function(value, onComplete) {};
/**
* Ensures 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).
*
* @param {*} value
* @param {number|string|null} priority
* @param {function(?Error)=} onComplete
* @return {!firebase.Promise<void>}
*/
firebase.database.OnDisconnect.prototype.setWithPriority = function(
value,
priority,
onComplete
) {};
/**
* Writes multiple values at this location when the client is disconnected (due
* to closing the browser, navigating to a new page, or network issues).
*
* 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).
*
* See more examples using the connected version of
* {@link firebase.database.Reference#update `update()`}.
*
* @example
* var ref = firebase.database().ref("users/ada");
* ref.update({
* onlineState: true,
* status: "I'm online."
* });
* ref.onDisconnect().update({
* onlineState: false,
* status: "I'm offline."
* });
*
* @param {!Object} values Object containing multiple values.
* @param {function(?Error)=} onComplete An optional callback function that will
* be called when synchronization to the server has completed. The
* callback will be passed a single parameter: null for success, or an Error
* object indicating a failure.
* @return {!firebase.Promise<void>} Resolves when synchronization to the
* Database is complete.
*/
firebase.database.OnDisconnect.prototype.update = function(
values,
onComplete
) {};