puppeteer-core
Version:
A high-level API to control headless Chrome over the DevTools Protocol
140 lines • 3.63 kB
JavaScript
/**
* @license
* Copyright 2022 Google Inc.
* SPDX-License-Identifier: Apache-2.0
*/
import { assert } from '../util/assert.js';
import { Deferred } from '../util/Deferred.js';
/**
* @internal
*/
export class MutationPoller {
#fn;
#root;
#observer;
#deferred;
constructor(fn, root) {
this.#fn = fn;
this.#root = root;
}
async start() {
const deferred = (this.#deferred = Deferred.create());
const result = await this.#fn();
if (result) {
deferred.resolve(result);
return;
}
this.#observer = new MutationObserver(async () => {
const result = await this.#fn();
if (!result) {
return;
}
deferred.resolve(result);
await this.stop();
});
this.#observer.observe(this.#root, {
childList: true,
subtree: true,
attributes: true,
});
}
async stop() {
assert(this.#deferred, 'Polling never started.');
if (!this.#deferred.finished()) {
this.#deferred.reject(new Error('Polling stopped'));
}
if (this.#observer) {
this.#observer.disconnect();
this.#observer = undefined;
}
}
result() {
assert(this.#deferred, 'Polling never started.');
return this.#deferred.valueOrThrow();
}
}
/**
* @internal
*/
export class RAFPoller {
#fn;
#deferred;
constructor(fn) {
this.#fn = fn;
}
async start() {
const deferred = (this.#deferred = Deferred.create());
const result = await this.#fn();
if (result) {
deferred.resolve(result);
return;
}
const poll = async () => {
if (deferred.finished()) {
return;
}
const result = await this.#fn();
if (!result) {
window.requestAnimationFrame(poll);
return;
}
deferred.resolve(result);
await this.stop();
};
window.requestAnimationFrame(poll);
}
async stop() {
assert(this.#deferred, 'Polling never started.');
if (!this.#deferred.finished()) {
this.#deferred.reject(new Error('Polling stopped'));
}
}
result() {
assert(this.#deferred, 'Polling never started.');
return this.#deferred.valueOrThrow();
}
}
/**
* @internal
*/
export class IntervalPoller {
#fn;
#ms;
#interval;
#deferred;
constructor(fn, ms) {
this.#fn = fn;
this.#ms = ms;
}
async start() {
const deferred = (this.#deferred = Deferred.create());
const result = await this.#fn();
if (result) {
deferred.resolve(result);
return;
}
this.#interval = setInterval(async () => {
const result = await this.#fn();
if (!result) {
return;
}
deferred.resolve(result);
await this.stop();
}, this.#ms);
}
async stop() {
assert(this.#deferred, 'Polling never started.');
if (!this.#deferred.finished()) {
this.#deferred.reject(new Error('Polling stopped'));
}
if (this.#interval) {
clearInterval(this.#interval);
this.#interval = undefined;
}
}
result() {
assert(this.#deferred, 'Polling never started.');
return this.#deferred.valueOrThrow();
}
}
//# sourceMappingURL=Poller.js.map