angular-docs-cn/packages/zone.js/lib/browser/property-descriptor-legacy.ts

125 lines
4.6 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
/**
* @fileoverview
* @suppress {globalThis}
*/
import * as webSocketPatch from './websocket';
export function propertyDescriptorLegacyPatch(api: _ZonePrivate, _global: any) {
const {isNode, isMix} = api.getGlobalObjects() !;
if (isNode && !isMix) {
return;
}
if (!canPatchViaPropertyDescriptor(api, _global)) {
const supportsWebSocket = typeof WebSocket !== 'undefined';
// Safari, Android browsers (Jelly Bean)
patchViaCapturingAllTheEvents(api);
api.patchClass('XMLHttpRequest');
if (supportsWebSocket) {
webSocketPatch.apply(api, _global);
}
(Zone as any)[api.symbol('patchEvents')] = true;
}
}
function canPatchViaPropertyDescriptor(api: _ZonePrivate, _global: any) {
const {isBrowser, isMix} = api.getGlobalObjects() !;
if ((isBrowser || isMix) &&
!api.ObjectGetOwnPropertyDescriptor(HTMLElement.prototype, 'onclick') &&
typeof Element !== 'undefined') {
// WebKit https://bugs.webkit.org/show_bug.cgi?id=134364
// IDL interface attributes are not configurable
const desc = api.ObjectGetOwnPropertyDescriptor(Element.prototype, 'onclick');
if (desc && !desc.configurable) return false;
// try to use onclick to detect whether we can patch via propertyDescriptor
// because XMLHttpRequest is not available in service worker
if (desc) {
api.ObjectDefineProperty(
Element.prototype, 'onclick',
{enumerable: true, configurable: true, get: function() { return true; }});
const div = document.createElement('div');
const result = !!div.onclick;
api.ObjectDefineProperty(Element.prototype, 'onclick', desc);
return result;
}
}
const XMLHttpRequest = _global['XMLHttpRequest'];
if (!XMLHttpRequest) {
// XMLHttpRequest is not available in service worker
return false;
}
const ON_READY_STATE_CHANGE = 'onreadystatechange';
const XMLHttpRequestPrototype = XMLHttpRequest.prototype;
const xhrDesc =
api.ObjectGetOwnPropertyDescriptor(XMLHttpRequestPrototype, ON_READY_STATE_CHANGE);
// add enumerable and configurable here because in opera
// by default XMLHttpRequest.prototype.onreadystatechange is undefined
// without adding enumerable and configurable will cause onreadystatechange
// non-configurable
// and if XMLHttpRequest.prototype.onreadystatechange is undefined,
// we should set a real desc instead a fake one
if (xhrDesc) {
api.ObjectDefineProperty(
XMLHttpRequestPrototype, ON_READY_STATE_CHANGE,
{enumerable: true, configurable: true, get: function() { return true; }});
const req = new XMLHttpRequest();
const result = !!req.onreadystatechange;
// restore original desc
api.ObjectDefineProperty(XMLHttpRequestPrototype, ON_READY_STATE_CHANGE, xhrDesc || {});
return result;
} else {
const SYMBOL_FAKE_ONREADYSTATECHANGE = api.symbol('fake');
api.ObjectDefineProperty(XMLHttpRequestPrototype, ON_READY_STATE_CHANGE, {
enumerable: true,
configurable: true,
get: function() { return this[SYMBOL_FAKE_ONREADYSTATECHANGE]; },
set: function(value) { this[SYMBOL_FAKE_ONREADYSTATECHANGE] = value; }
});
const req = new XMLHttpRequest();
const detectFunc = () => {};
req.onreadystatechange = detectFunc;
const result = (req as any)[SYMBOL_FAKE_ONREADYSTATECHANGE] === detectFunc;
req.onreadystatechange = null as any;
return result;
}
}
// Whenever any eventListener fires, we check the eventListener target and all parents
// for `onwhatever` properties and replace them with zone-bound functions
// - Chrome (for now)
function patchViaCapturingAllTheEvents(api: _ZonePrivate) {
const {eventNames} = api.getGlobalObjects() !;
const unboundKey = api.symbol('unbound');
for (let i = 0; i < eventNames.length; i++) {
const property = eventNames[i];
const onproperty = 'on' + property;
self.addEventListener(property, function(event) {
let elt: any = <Node>event.target, bound, source;
if (elt) {
source = elt.constructor['name'] + '.' + onproperty;
} else {
source = 'unknown.' + onproperty;
}
while (elt) {
if (elt[onproperty] && !elt[onproperty][unboundKey]) {
bound = api.wrapWithCurrentZone(elt[onproperty], source);
bound[unboundKey] = elt[onproperty];
elt[onproperty] = bound;
}
elt = elt.parentElement;
}
}, true);
}
}