electron/lib/renderer/api/remote.ts

395 lines
14 KiB
TypeScript

import { CallbacksRegistry } from '../remote/callbacks-registry';
import { isPromise, isSerializableObject, serialize, deserialize } from '../../common/type-utils';
import { MetaTypeFromRenderer, ObjectMember, ObjProtoDescriptor, MetaType } from '../../common/remote/types';
import { ipcRendererInternal } from '../ipc-renderer-internal';
import type { BrowserWindow, WebContents } from 'electron/main';
import deprecate from '@electron/internal/common/api/deprecate';
import { browserModuleNames } from '@electron/internal/browser/api/module-names';
import { commonModuleList } from '@electron/internal/common/api/module-list';
import { IPC_MESSAGES } from '@electron/internal/common/remote/ipc-messages';
deprecate.log('The remote module is deprecated. Use https://github.com/electron/remote instead.');
const v8Util = process._linkedBinding('electron_common_v8_util');
const { hasSwitch } = process._linkedBinding('electron_common_command_line');
const callbacksRegistry = new CallbacksRegistry();
const remoteObjectCache = new Map();
const finalizationRegistry = new FinalizationRegistry((id: number) => {
const ref = remoteObjectCache.get(id);
if (ref !== undefined && ref.deref() === undefined) {
remoteObjectCache.delete(id);
ipcRendererInternal.send(IPC_MESSAGES.BROWSER_DEREFERENCE, contextId, id, 0);
}
});
const electronIds = new WeakMap<Object, number>();
const isReturnValue = new WeakSet<Object>();
function getCachedRemoteObject (id: number) {
const ref = remoteObjectCache.get(id);
if (ref !== undefined) {
const deref = ref.deref();
if (deref !== undefined) return deref;
}
}
function setCachedRemoteObject (id: number, value: any) {
const wr = new WeakRef(value);
remoteObjectCache.set(id, wr);
finalizationRegistry.register(value, id);
return value;
}
// An unique ID that can represent current context.
const contextId = v8Util.getHiddenValue<string>(global, 'contextId');
// Notify the main process when current context is going to be released.
// Note that when the renderer process is destroyed, the message may not be
// sent, we also listen to the "render-view-deleted" event in the main process
// to guard that situation.
process.on('exit', () => {
const command = IPC_MESSAGES.BROWSER_CONTEXT_RELEASE;
ipcRendererInternal.send(command, contextId);
});
const IS_REMOTE_PROXY = Symbol('is-remote-proxy');
// Convert the arguments object into an array of meta data.
function wrapArgs (args: any[], visited = new Set()): any {
const valueToMeta = (value: any): any => {
// Check for circular reference.
if (visited.has(value)) {
return {
type: 'value',
value: null
};
}
if (value && value.constructor && value.constructor.name === 'NativeImage') {
return { type: 'nativeimage', value: serialize(value) };
} else if (Array.isArray(value)) {
visited.add(value);
const meta = {
type: 'array',
value: wrapArgs(value, visited)
};
visited.delete(value);
return meta;
} else if (value instanceof Buffer) {
return {
type: 'buffer',
value
};
} else if (isSerializableObject(value)) {
return {
type: 'value',
value
};
} else if (typeof value === 'object') {
if (isPromise(value)) {
return {
type: 'promise',
then: valueToMeta(function (onFulfilled: Function, onRejected: Function) {
value.then(onFulfilled, onRejected);
})
};
} else if (electronIds.has(value)) {
return {
type: 'remote-object',
id: electronIds.get(value)
};
}
const meta: MetaTypeFromRenderer = {
type: 'object',
name: value.constructor ? value.constructor.name : '',
members: []
};
visited.add(value);
for (const prop in value) { // eslint-disable-line guard-for-in
meta.members.push({
name: prop,
value: valueToMeta(value[prop])
});
}
visited.delete(value);
return meta;
} else if (typeof value === 'function' && isReturnValue.has(value)) {
return {
type: 'function-with-return-value',
value: valueToMeta(value())
};
} else if (typeof value === 'function') {
return {
type: 'function',
id: callbacksRegistry.add(value),
location: callbacksRegistry.getLocation(value),
length: value.length
};
} else {
return {
type: 'value',
value
};
}
};
return args.map(valueToMeta);
}
// Populate object's members from descriptors.
// The |ref| will be kept referenced by |members|.
// This matches |getObjectMembers| in rpc-server.
function setObjectMembers (ref: any, object: any, metaId: number, members: ObjectMember[]) {
if (!Array.isArray(members)) return;
for (const member of members) {
if (Object.prototype.hasOwnProperty.call(object, member.name)) continue;
const descriptor: PropertyDescriptor = { enumerable: member.enumerable };
if (member.type === 'method') {
const remoteMemberFunction = function (this: any, ...args: any[]) {
let command;
if (this && this.constructor === remoteMemberFunction) {
command = IPC_MESSAGES.BROWSER_MEMBER_CONSTRUCTOR;
} else {
command = IPC_MESSAGES.BROWSER_MEMBER_CALL;
}
const ret = ipcRendererInternal.sendSync(command, contextId, metaId, member.name, wrapArgs(args));
return metaToValue(ret);
};
let descriptorFunction = proxyFunctionProperties(remoteMemberFunction, metaId, member.name);
descriptor.get = () => {
descriptorFunction.ref = ref; // The member should reference its object.
return descriptorFunction;
};
// Enable monkey-patch the method
descriptor.set = (value) => {
descriptorFunction = value;
return value;
};
descriptor.configurable = true;
} else if (member.type === 'get') {
descriptor.get = () => {
const command = IPC_MESSAGES.BROWSER_MEMBER_GET;
const meta = ipcRendererInternal.sendSync(command, contextId, metaId, member.name);
return metaToValue(meta);
};
if (member.writable) {
descriptor.set = (value) => {
const args = wrapArgs([value]);
const command = IPC_MESSAGES.BROWSER_MEMBER_SET;
const meta = ipcRendererInternal.sendSync(command, contextId, metaId, member.name, args);
if (meta != null) metaToValue(meta);
return value;
};
}
}
Object.defineProperty(object, member.name, descriptor);
}
}
// Populate object's prototype from descriptor.
// This matches |getObjectPrototype| in rpc-server.
function setObjectPrototype (ref: any, object: any, metaId: number, descriptor: ObjProtoDescriptor) {
if (descriptor === null) return;
const proto = {};
setObjectMembers(ref, proto, metaId, descriptor.members);
setObjectPrototype(ref, proto, metaId, descriptor.proto);
Object.setPrototypeOf(object, proto);
}
// Wrap function in Proxy for accessing remote properties
function proxyFunctionProperties (remoteMemberFunction: Function, metaId: number, name: string) {
let loaded = false;
// Lazily load function properties
const loadRemoteProperties = () => {
if (loaded) return;
loaded = true;
const command = IPC_MESSAGES.BROWSER_MEMBER_GET;
const meta = ipcRendererInternal.sendSync(command, contextId, metaId, name);
setObjectMembers(remoteMemberFunction, remoteMemberFunction, meta.id, meta.members);
};
return new Proxy(remoteMemberFunction as any, {
set: (target, property, value) => {
if (property !== 'ref') loadRemoteProperties();
target[property] = value;
return true;
},
get: (target, property) => {
if (property === IS_REMOTE_PROXY) return true;
if (!Object.prototype.hasOwnProperty.call(target, property)) loadRemoteProperties();
const value = target[property];
if (property === 'toString' && typeof value === 'function') {
return value.bind(target);
}
return value;
},
ownKeys: (target) => {
loadRemoteProperties();
return Object.getOwnPropertyNames(target);
},
getOwnPropertyDescriptor: (target, property) => {
const descriptor = Object.getOwnPropertyDescriptor(target, property);
if (descriptor) return descriptor;
loadRemoteProperties();
return Object.getOwnPropertyDescriptor(target, property);
}
});
}
// Convert meta data from browser into real value.
function metaToValue (meta: MetaType): any {
if (meta.type === 'value') {
return meta.value;
} else if (meta.type === 'array') {
return meta.members.map((member) => metaToValue(member));
} else if (meta.type === 'nativeimage') {
return deserialize(meta.value);
} else if (meta.type === 'buffer') {
return Buffer.from(meta.value.buffer, meta.value.byteOffset, meta.value.byteLength);
} else if (meta.type === 'promise') {
return Promise.resolve({ then: metaToValue(meta.then) });
} else if (meta.type === 'error') {
return metaToError(meta);
} else if (meta.type === 'exception') {
if (meta.value.type === 'error') { throw metaToError(meta.value); } else { throw new Error(`Unexpected value type in exception: ${meta.value.type}`); }
} else {
let ret;
if ('id' in meta) {
const cached = getCachedRemoteObject(meta.id);
if (cached !== undefined) { return cached; }
}
// A shadow class to represent the remote function object.
if (meta.type === 'function') {
const remoteFunction = function (this: any, ...args: any[]) {
let command;
if (this && this.constructor === remoteFunction) {
command = IPC_MESSAGES.BROWSER_CONSTRUCTOR;
} else {
command = IPC_MESSAGES.BROWSER_FUNCTION_CALL;
}
const obj = ipcRendererInternal.sendSync(command, contextId, meta.id, wrapArgs(args));
return metaToValue(obj);
};
ret = remoteFunction;
} else {
ret = {};
}
setObjectMembers(ret, ret, meta.id, meta.members);
setObjectPrototype(ret, ret, meta.id, meta.proto);
if (ret.constructor && (ret.constructor as any)[IS_REMOTE_PROXY]) {
Object.defineProperty(ret.constructor, 'name', { value: meta.name });
}
// Track delegate obj's lifetime & tell browser to clean up when object is GCed.
electronIds.set(ret, meta.id);
setCachedRemoteObject(meta.id, ret);
return ret;
}
}
function metaToError (meta: { type: 'error', value: any, members: ObjectMember[] }) {
const obj = meta.value;
for (const { name, value } of meta.members) {
obj[name] = metaToValue(value);
}
return obj;
}
function handleMessage (channel: string, handler: Function) {
ipcRendererInternal.on(channel, (event, passedContextId, id, ...args) => {
if (passedContextId === contextId) {
handler(id, ...args);
} else {
// Message sent to an un-exist context, notify the error to main process.
ipcRendererInternal.send(IPC_MESSAGES.BROWSER_WRONG_CONTEXT_ERROR, contextId, passedContextId, id);
}
});
}
const enableStacks = hasSwitch('enable-api-filtering-logging');
function getCurrentStack (): string | undefined {
const target = { stack: undefined as string | undefined };
if (enableStacks) {
Error.captureStackTrace(target, getCurrentStack);
}
return target.stack;
}
// Browser calls a callback in renderer.
handleMessage(IPC_MESSAGES.RENDERER_CALLBACK, (id: number, args: any) => {
callbacksRegistry.apply(id, metaToValue(args));
});
// A callback in browser is released.
handleMessage(IPC_MESSAGES.RENDERER_RELEASE_CALLBACK, (id: number) => {
callbacksRegistry.remove(id);
});
exports.require = (module: string) => {
const command = IPC_MESSAGES.BROWSER_REQUIRE;
const meta = ipcRendererInternal.sendSync(command, contextId, module, getCurrentStack());
return metaToValue(meta);
};
// Alias to remote.require('electron').xxx.
export function getBuiltin (module: string) {
const command = IPC_MESSAGES.BROWSER_GET_BUILTIN;
const meta = ipcRendererInternal.sendSync(command, contextId, module, getCurrentStack());
return metaToValue(meta);
}
export function getCurrentWindow (): BrowserWindow {
const command = IPC_MESSAGES.BROWSER_GET_CURRENT_WINDOW;
const meta = ipcRendererInternal.sendSync(command, contextId, getCurrentStack());
return metaToValue(meta);
}
// Get current WebContents object.
export function getCurrentWebContents (): WebContents {
const command = IPC_MESSAGES.BROWSER_GET_CURRENT_WEB_CONTENTS;
const meta = ipcRendererInternal.sendSync(command, contextId, getCurrentStack());
return metaToValue(meta);
}
// Get a global object in browser.
export function getGlobal<T = any> (name: string): T {
const command = IPC_MESSAGES.BROWSER_GET_GLOBAL;
const meta = ipcRendererInternal.sendSync(command, contextId, name, getCurrentStack());
return metaToValue(meta);
}
// Get the process object in browser.
Object.defineProperty(exports, 'process', {
get: () => exports.getGlobal('process')
});
// Create a function that will return the specified value when called in browser.
export function createFunctionWithReturnValue<T> (returnValue: T): () => T {
const func = () => returnValue;
isReturnValue.add(func);
return func;
}
const addBuiltinProperty = (name: string) => {
Object.defineProperty(exports, name, {
get: () => exports.getBuiltin(name)
});
};
const browserModules = commonModuleList.concat(browserModuleNames.map(name => ({ name, loader: () => {} })));
// And add a helper receiver for each one.
browserModules
.filter((m) => !m.private)
.map((m) => m.name)
.forEach(addBuiltinProperty);