/** * Copyright 2023 Google Inc. All rights reserved. * * 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 Protocol from 'devtools-protocol'; import {Symbol} from '../../third_party/disposablestack/disposablestack.js'; import {EvaluateFuncWith, HandleFor, HandleOr} from '../common/types.js'; import {debugError} from '../common/util.js'; import {ElementHandle} from './ElementHandle.js'; /** * Represents a reference to a JavaScript object. Instances can be created using * {@link Page.evaluateHandle}. * * Handles prevent the referenced JavaScript object from being garbage-collected * unless the handle is purposely {@link JSHandle.dispose | disposed}. JSHandles * are auto-disposed when their associated frame is navigated away or the parent * context gets destroyed. * * Handles can be used as arguments for any evaluation function such as * {@link Page.$eval}, {@link Page.evaluate}, and {@link Page.evaluateHandle}. * They are resolved to their referenced object. * * @example * * ```ts * const windowHandle = await page.evaluateHandle(() => window); * ``` * * @public */ export abstract class JSHandle implements Disposable, AsyncDisposable { /** * Used for nominally typing {@link JSHandle}. */ declare _?: T; /** * @internal */ constructor() {} /** * @internal */ get disposed(): boolean { throw new Error('Not implemented'); } /** * Evaluates the given function with the current handle as its first argument. */ abstract evaluate< Params extends unknown[], Func extends EvaluateFuncWith = EvaluateFuncWith, >( pageFunction: Func | string, ...args: Params ): Promise>>; /** * Evaluates the given function with the current handle as its first argument. * */ abstract evaluateHandle< Params extends unknown[], Func extends EvaluateFuncWith = EvaluateFuncWith, >( pageFunction: Func | string, ...args: Params ): Promise>>>; /** * Fetches a single property from the referenced object. */ abstract getProperty( propertyName: HandleOr ): Promise>; abstract getProperty(propertyName: string): Promise>; /** * Gets a map of handles representing the properties of the current handle. * * @example * * ```ts * const listHandle = await page.evaluateHandle(() => document.body.children); * const properties = await listHandle.getProperties(); * const children = []; * for (const property of properties.values()) { * const element = property.asElement(); * if (element) { * children.push(element); * } * } * children; // holds elementHandles to all children of document.body * ``` */ abstract getProperties(): Promise>>; /** * A vanilla object representing the serializable portions of the * referenced object. * @throws Throws if the object cannot be serialized due to circularity. * * @remarks * If the object has a `toJSON` function, it **will not** be called. */ abstract jsonValue(): Promise; /** * Either `null` or the handle itself if the handle is an * instance of {@link ElementHandle}. */ abstract asElement(): ElementHandle | null; /** * Releases the object referenced by the handle for garbage collection. */ abstract dispose(): Promise; /** * Returns a string representation of the JSHandle. * * @remarks * Useful during debugging. */ abstract toString(): string; /** * @internal */ abstract get id(): string | undefined; /** * Provides access to the * {@link https://chromedevtools.github.io/devtools-protocol/tot/Runtime/#type-RemoteObject | Protocol.Runtime.RemoteObject} * backing this handle. */ abstract remoteObject(): Protocol.Runtime.RemoteObject; [Symbol.dispose](): void { return void this.dispose().catch(debugError); } [Symbol.asyncDispose](): Promise { return this.dispose(); } }