puppeteer-core
Version:
A high-level API to control headless Chrome over the DevTools Protocol
313 lines • 14.1 kB
JavaScript
/**
* @license
* Copyright 2022 Google Inc.
* SPDX-License-Identifier: Apache-2.0
*/
import { CDPSession, CDPSessionEvent } from '../api/CDPSession.js';
import { EventEmitter } from '../common/EventEmitter.js';
import { debugError } from '../common/util.js';
import { assert } from '../util/assert.js';
import { Deferred } from '../util/Deferred.js';
import { CdpCDPSession } from './CdpSession.js';
import { CdpTarget, InitializationStatus } from './Target.js';
function isPageTargetBecomingPrimary(target, newTargetInfo) {
return Boolean(target._subtype()) && !newTargetInfo.subtype;
}
/**
* TargetManager encapsulates all interactions with CDP targets and is
* responsible for coordinating the configuration of targets with the rest of
* Puppeteer. Code outside of this class should not subscribe `Target.*` events
* and only use the TargetManager events.
*
* TargetManager uses the CDP's auto-attach mechanism to intercept
* new targets and allow the rest of Puppeteer to configure listeners while
* the target is paused.
*
* @internal
*/
export class TargetManager extends EventEmitter {
#connection;
/**
* Keeps track of the following events: 'Target.targetCreated',
* 'Target.targetDestroyed', 'Target.targetInfoChanged'.
*
* A target becomes discovered when 'Target.targetCreated' is received.
* A target is removed from this map once 'Target.targetDestroyed' is
* received.
*
* `targetFilterCallback` has no effect on this map.
*/
#discoveredTargetsByTargetId = new Map();
/**
* A target is added to this map once TargetManager has created
* a Target and attached at least once to it.
*/
#attachedTargetsByTargetId = new Map();
/**
* Tracks which sessions attach to which target.
*/
#attachedTargetsBySessionId = new Map();
/**
* If a target was filtered out by `targetFilterCallback`, we still receive
* events about it from CDP, but we don't forward them to the rest of Puppeteer.
*/
#ignoredTargets = new Set();
#targetFilterCallback;
#targetFactory;
#attachedToTargetListenersBySession = new WeakMap();
#detachedFromTargetListenersBySession = new WeakMap();
#initializeDeferred = Deferred.create();
#targetsIdsForInit = new Set();
#waitForInitiallyDiscoveredTargets = true;
#discoveryFilter = [{}];
constructor(connection, targetFactory, targetFilterCallback, waitForInitiallyDiscoveredTargets = true) {
super();
this.#connection = connection;
this.#targetFilterCallback = targetFilterCallback;
this.#targetFactory = targetFactory;
this.#waitForInitiallyDiscoveredTargets = waitForInitiallyDiscoveredTargets;
this.#connection.on('Target.targetCreated', this.#onTargetCreated);
this.#connection.on('Target.targetDestroyed', this.#onTargetDestroyed);
this.#connection.on('Target.targetInfoChanged', this.#onTargetInfoChanged);
this.#connection.on(CDPSessionEvent.SessionDetached, this.#onSessionDetached);
this.#setupAttachmentListeners(this.#connection);
}
#storeExistingTargetsForInit = () => {
if (!this.#waitForInitiallyDiscoveredTargets) {
return;
}
for (const [targetId, targetInfo,] of this.#discoveredTargetsByTargetId.entries()) {
const targetForFilter = new CdpTarget(targetInfo, undefined, undefined, this, undefined);
// Only wait for pages and frames (except those from extensions)
// to auto-attach.
const isPageOrFrame = targetInfo.type === 'page' || targetInfo.type === 'iframe';
const isExtension = targetInfo.url.startsWith('chrome-extension://');
if ((!this.#targetFilterCallback ||
this.#targetFilterCallback(targetForFilter)) &&
isPageOrFrame &&
!isExtension) {
this.#targetsIdsForInit.add(targetId);
}
}
};
async initialize() {
await this.#connection.send('Target.setDiscoverTargets', {
discover: true,
filter: this.#discoveryFilter,
});
this.#storeExistingTargetsForInit();
await this.#connection.send('Target.setAutoAttach', {
waitForDebuggerOnStart: true,
flatten: true,
autoAttach: true,
filter: [
{
type: 'page',
exclude: true,
},
...this.#discoveryFilter,
],
});
this.#finishInitializationIfReady();
await this.#initializeDeferred.valueOrThrow();
}
getChildTargets(target) {
return target._childTargets();
}
dispose() {
this.#connection.off('Target.targetCreated', this.#onTargetCreated);
this.#connection.off('Target.targetDestroyed', this.#onTargetDestroyed);
this.#connection.off('Target.targetInfoChanged', this.#onTargetInfoChanged);
this.#connection.off(CDPSessionEvent.SessionDetached, this.#onSessionDetached);
this.#removeAttachmentListeners(this.#connection);
}
getAvailableTargets() {
return this.#attachedTargetsByTargetId;
}
#setupAttachmentListeners(session) {
const listener = (event) => {
void this.#onAttachedToTarget(session, event);
};
assert(!this.#attachedToTargetListenersBySession.has(session));
this.#attachedToTargetListenersBySession.set(session, listener);
session.on('Target.attachedToTarget', listener);
const detachedListener = (event) => {
return this.#onDetachedFromTarget(session, event);
};
assert(!this.#detachedFromTargetListenersBySession.has(session));
this.#detachedFromTargetListenersBySession.set(session, detachedListener);
session.on('Target.detachedFromTarget', detachedListener);
}
#removeAttachmentListeners(session) {
const listener = this.#attachedToTargetListenersBySession.get(session);
if (listener) {
session.off('Target.attachedToTarget', listener);
this.#attachedToTargetListenersBySession.delete(session);
}
if (this.#detachedFromTargetListenersBySession.has(session)) {
session.off('Target.detachedFromTarget', this.#detachedFromTargetListenersBySession.get(session));
this.#detachedFromTargetListenersBySession.delete(session);
}
}
#onSessionDetached = (session) => {
this.#removeAttachmentListeners(session);
};
#onTargetCreated = async (event) => {
this.#discoveredTargetsByTargetId.set(event.targetInfo.targetId, event.targetInfo);
this.emit("targetDiscovered" /* TargetManagerEvent.TargetDiscovered */, event.targetInfo);
// The connection is already attached to the browser target implicitly,
// therefore, no new CDPSession is created and we have special handling
// here.
if (event.targetInfo.type === 'browser' && event.targetInfo.attached) {
if (this.#attachedTargetsByTargetId.has(event.targetInfo.targetId)) {
return;
}
const target = this.#targetFactory(event.targetInfo, undefined);
target._initialize();
this.#attachedTargetsByTargetId.set(event.targetInfo.targetId, target);
}
};
#onTargetDestroyed = (event) => {
const targetInfo = this.#discoveredTargetsByTargetId.get(event.targetId);
this.#discoveredTargetsByTargetId.delete(event.targetId);
this.#finishInitializationIfReady(event.targetId);
if (targetInfo?.type === 'service_worker' &&
this.#attachedTargetsByTargetId.has(event.targetId)) {
// Special case for service workers: report TargetGone event when
// the worker is destroyed.
const target = this.#attachedTargetsByTargetId.get(event.targetId);
if (target) {
this.emit("targetGone" /* TargetManagerEvent.TargetGone */, target);
this.#attachedTargetsByTargetId.delete(event.targetId);
}
}
};
#onTargetInfoChanged = (event) => {
this.#discoveredTargetsByTargetId.set(event.targetInfo.targetId, event.targetInfo);
if (this.#ignoredTargets.has(event.targetInfo.targetId) ||
!this.#attachedTargetsByTargetId.has(event.targetInfo.targetId) ||
!event.targetInfo.attached) {
return;
}
const target = this.#attachedTargetsByTargetId.get(event.targetInfo.targetId);
if (!target) {
return;
}
const previousURL = target.url();
const wasInitialized = target._initializedDeferred.value() === InitializationStatus.SUCCESS;
if (isPageTargetBecomingPrimary(target, event.targetInfo)) {
const session = target?._session();
assert(session, 'Target that is being activated is missing a CDPSession.');
session.parentSession()?.emit(CDPSessionEvent.Swapped, session);
}
target._targetInfoChanged(event.targetInfo);
if (wasInitialized && previousURL !== target.url()) {
this.emit("targetChanged" /* TargetManagerEvent.TargetChanged */, {
target,
wasInitialized,
previousURL,
});
}
};
#onAttachedToTarget = async (parentSession, event) => {
const targetInfo = event.targetInfo;
const session = this.#connection._session(event.sessionId);
if (!session) {
throw new Error(`Session ${event.sessionId} was not created.`);
}
const silentDetach = async () => {
await session.send('Runtime.runIfWaitingForDebugger').catch(debugError);
// We don't use `session.detach()` because that dispatches all commands on
// the connection instead of the parent session.
await parentSession
.send('Target.detachFromTarget', {
sessionId: session.id(),
})
.catch(debugError);
};
if (!this.#connection.isAutoAttached(targetInfo.targetId)) {
return;
}
// Special case for service workers: being attached to service workers will
// prevent them from ever being destroyed. Therefore, we silently detach
// from service workers unless the connection was manually created via
// `page.worker()`. To determine this, we use
// `this.#connection.isAutoAttached(targetInfo.targetId)`. In the future, we
// should determine if a target is auto-attached or not with the help of
// CDP.
if (targetInfo.type === 'service_worker') {
this.#finishInitializationIfReady(targetInfo.targetId);
await silentDetach();
if (this.#attachedTargetsByTargetId.has(targetInfo.targetId)) {
return;
}
const target = this.#targetFactory(targetInfo);
target._initialize();
this.#attachedTargetsByTargetId.set(targetInfo.targetId, target);
this.emit("targetAvailable" /* TargetManagerEvent.TargetAvailable */, target);
return;
}
const isExistingTarget = this.#attachedTargetsByTargetId.has(targetInfo.targetId);
const target = isExistingTarget
? this.#attachedTargetsByTargetId.get(targetInfo.targetId)
: this.#targetFactory(targetInfo, session, parentSession instanceof CdpCDPSession ? parentSession : undefined);
if (this.#targetFilterCallback && !this.#targetFilterCallback(target)) {
this.#ignoredTargets.add(targetInfo.targetId);
this.#finishInitializationIfReady(targetInfo.targetId);
await silentDetach();
return;
}
this.#setupAttachmentListeners(session);
if (isExistingTarget) {
session.setTarget(target);
this.#attachedTargetsBySessionId.set(session.id(), this.#attachedTargetsByTargetId.get(targetInfo.targetId));
}
else {
target._initialize();
this.#attachedTargetsByTargetId.set(targetInfo.targetId, target);
this.#attachedTargetsBySessionId.set(session.id(), target);
}
const parentTarget = parentSession instanceof CDPSession
? parentSession.target()
: null;
parentTarget?._addChildTarget(target);
parentSession.emit(CDPSessionEvent.Ready, session);
this.#targetsIdsForInit.delete(target._targetId);
if (!isExistingTarget) {
this.emit("targetAvailable" /* TargetManagerEvent.TargetAvailable */, target);
}
this.#finishInitializationIfReady();
// TODO: the browser might be shutting down here. What do we do with the
// error?
await Promise.all([
session.send('Target.setAutoAttach', {
waitForDebuggerOnStart: true,
flatten: true,
autoAttach: true,
filter: this.#discoveryFilter,
}),
session.send('Runtime.runIfWaitingForDebugger'),
]).catch(debugError);
};
#finishInitializationIfReady(targetId) {
if (targetId !== undefined) {
this.#targetsIdsForInit.delete(targetId);
}
if (this.#targetsIdsForInit.size === 0) {
this.#initializeDeferred.resolve();
}
}
#onDetachedFromTarget = (parentSession, event) => {
const target = this.#attachedTargetsBySessionId.get(event.sessionId);
this.#attachedTargetsBySessionId.delete(event.sessionId);
if (!target) {
return;
}
if (parentSession instanceof CDPSession) {
parentSession.target()._removeChildTarget(target);
}
this.#attachedTargetsByTargetId.delete(target._targetId);
this.emit("targetGone" /* TargetManagerEvent.TargetGone */, target);
};
}
//# sourceMappingURL=TargetManager.js.map