puppeteer-core
Version:
A high-level API to control headless Chrome over the DevTools Protocol
113 lines (112 loc) • 4.93 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.WebWorker = void 0;
/**
* Copyright 2018 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.
*/
const EventEmitter_js_1 = require("./EventEmitter.js");
const helper_js_1 = require("./helper.js");
const ExecutionContext_js_1 = require("./ExecutionContext.js");
const JSHandle_js_1 = require("./JSHandle.js");
/**
* The WebWorker class represents a
* {@link https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API | WebWorker}.
*
* @remarks
* The events `workercreated` and `workerdestroyed` are emitted on the page
* object to signal the worker lifecycle.
*
* @example
* ```js
* page.on('workercreated', worker => console.log('Worker created: ' + worker.url()));
* page.on('workerdestroyed', worker => console.log('Worker destroyed: ' + worker.url()));
*
* console.log('Current workers:');
* for (const worker of page.workers()) {
* console.log(' ' + worker.url());
* }
* ```
*
* @public
*/
class WebWorker extends EventEmitter_js_1.EventEmitter {
/**
*
* @internal
*/
constructor(client, url, consoleAPICalled, exceptionThrown) {
super();
this._client = client;
this._url = url;
this._executionContextPromise = new Promise((x) => (this._executionContextCallback = x));
let jsHandleFactory;
this._client.once('Runtime.executionContextCreated', async (event) => {
// eslint-disable-next-line @typescript-eslint/explicit-function-return-type
jsHandleFactory = (remoteObject) => new JSHandle_js_1.JSHandle(executionContext, client, remoteObject);
const executionContext = new ExecutionContext_js_1.ExecutionContext(client, event.context, null);
this._executionContextCallback(executionContext);
});
// This might fail if the target is closed before we recieve all execution contexts.
this._client.send('Runtime.enable').catch(helper_js_1.debugError);
this._client.on('Runtime.consoleAPICalled', (event) => consoleAPICalled(event.type, event.args.map(jsHandleFactory), event.stackTrace));
this._client.on('Runtime.exceptionThrown', (exception) => exceptionThrown(exception.exceptionDetails));
}
/**
* @returns The URL of this web worker.
*/
url() {
return this._url;
}
/**
* Returns the ExecutionContext the WebWorker runs in
* @returns The ExecutionContext the web worker runs in.
*/
async executionContext() {
return this._executionContextPromise;
}
/**
* If the function passed to the `worker.evaluate` returns a Promise, then
* `worker.evaluate` would wait for the promise to resolve and return its
* value. If the function passed to the `worker.evaluate` returns a
* non-serializable value, then `worker.evaluate` resolves to `undefined`.
* DevTools Protocol also supports transferring some additional values that
* are not serializable by `JSON`: `-0`, `NaN`, `Infinity`, `-Infinity`, and
* bigint literals.
* Shortcut for `await worker.executionContext()).evaluate(pageFunction, ...args)`.
*
* @param pageFunction - Function to be evaluated in the worker context.
* @param args - Arguments to pass to `pageFunction`.
* @returns Promise which resolves to the return value of `pageFunction`.
*/
async evaluate(pageFunction, ...args) {
return (await this._executionContextPromise).evaluate(pageFunction, ...args);
}
/**
* The only difference between `worker.evaluate` and `worker.evaluateHandle`
* is that `worker.evaluateHandle` returns in-page object (JSHandle). If the
* function passed to the `worker.evaluateHandle` returns a [Promise], then
* `worker.evaluateHandle` would wait for the promise to resolve and return
* its value. Shortcut for
* `await worker.executionContext()).evaluateHandle(pageFunction, ...args)`
*
* @param pageFunction - Function to be evaluated in the page context.
* @param args - Arguments to pass to `pageFunction`.
* @returns Promise which resolves to the return value of `pageFunction`.
*/
async evaluateHandle(pageFunction, ...args) {
return (await this._executionContextPromise).evaluateHandle(pageFunction, ...args);
}
}
exports.WebWorker = WebWorker;