| // Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| // This file defines the module loader for the dart runtime. |
| if (!self.dart_library) { |
| self.dart_library = typeof module != 'undefined' && module.exports || {}; |
| |
| (function(dart_library) { |
| 'use strict'; |
| |
| // Throws an error related to module loading. |
| // |
| // This does not throw a Dart error because the Dart SDK may not have loaded |
| // yet, and module loading errors cannot be caught by Dart code. |
| function throwLibraryError(message) { |
| // Dispatch event to allow others to react to the load error without |
| // capturing the exception. |
| if (!!self.dispatchEvent) { |
| self.dispatchEvent( |
| new CustomEvent('dartLoadException', {detail: message})); |
| } |
| throw Error(message); |
| } |
| |
| const libraryImports = Symbol('libraryImports'); |
| self.dart_library.libraryImports = libraryImports; |
| |
| const _metrics = Symbol('metrics'); |
| |
| // Returns a map from module name to various metrics for module. |
| function moduleMetrics() { |
| const map = {}; |
| const keys = Array.from(_libraries.keys()); |
| for (const key of keys) { |
| const lib = _libraries.get(key); |
| map[lib._name] = lib.firstLibraryValue[_metrics]; |
| } |
| return map; |
| } |
| self.dart_library.moduleMetrics = moduleMetrics; |
| |
| // Returns an application level overview of the module metrics. |
| function appMetrics() { |
| const metrics = moduleMetrics(); |
| let dartSize = 0; |
| let jsSize = 0; |
| let sourceMapSize = 0; |
| let evaluatedModules = 0; |
| const keys = Array.from(_libraries.keys()); |
| |
| let firstLoadStart = Number.MAX_VALUE; |
| let lastLoadEnd = Number.MIN_VALUE; |
| |
| for (const module of keys) { |
| let data = metrics[module]; |
| if (data != null) { |
| evaluatedModules++; |
| dartSize += data.dartSize; |
| jsSize += data.jsSize; |
| sourceMapSize += data.sourceMapSize; |
| firstLoadStart = Math.min(firstLoadStart, data.loadStart); |
| lastLoadEnd = Math.max(lastLoadEnd, data.loadEnd); |
| } |
| } |
| return { |
| 'dartSize': dartSize, |
| 'jsSize': jsSize, |
| 'sourceMapSize': sourceMapSize, |
| 'evaluatedModules': evaluatedModules, |
| 'loadTimeMs': lastLoadEnd - firstLoadStart |
| }; |
| } |
| self.dart_library.appMetrics = appMetrics; |
| |
| function _sortFn(key1, key2) { |
| const t1 = _libraries.get(key1).firstLibraryValue[_metrics].loadStart; |
| const t2 = _libraries.get(key2).firstLibraryValue[_metrics].loadStart; |
| return t1 - t2; |
| } |
| |
| // Convenience method to print the metrics in the browser console |
| // in CSV format. |
| function metricsCsv() { |
| let buffer = |
| 'Module, JS Size, Dart Size, Load Start, Load End, Cumulative JS Size\n'; |
| const keys = Array.from(_libraries.keys()); |
| keys.sort(_sortFn); |
| let cumulativeJsSize = 0; |
| for (const key of keys) { |
| const lib = _libraries.get(key); |
| const jsSize = lib.firstLibraryValue[_metrics].jsSize; |
| cumulativeJsSize += jsSize; |
| const dartSize = lib.firstLibraryValue[_metrics].dartSize; |
| const loadStart = lib.firstLibraryValue[_metrics].loadStart; |
| const loadEnd = lib.firstLibraryValue[_metrics].loadEnd; |
| buffer += '"' + lib._name + '", ' + jsSize + ', ' + dartSize + ', ' + |
| loadStart + ', ' + loadEnd + ', ' + cumulativeJsSize + '\n'; |
| } |
| return buffer; |
| } |
| self.dart_library.metricsCsv = metricsCsv; |
| |
| // Module support. This is a simplified module system for Dart. |
| // Longer term, we can easily migrate to an existing JS module system: |
| // ES6, AMD, RequireJS, .... |
| |
| // Returns a proxy that delegates to the underlying loader. |
| // This defers loading of a module until a library is actually used. |
| const loadedModule = Symbol('loadedModule'); |
| self.dart_library.defer = function(module, name, patch) { |
| let done = false; |
| function loadDeferred() { |
| done = true; |
| let mod = module[loadedModule]; |
| let lib = mod[name]; |
| // Install unproxied module and library in caller's context. |
| patch(mod, lib); |
| } |
| // The deferred library object. Note, the only legal operations on a Dart |
| // library object should be get (to read a top-level variable, method, or |
| // Class) or set (to write a top-level variable). |
| return new Proxy({}, { |
| get: function(o, p) { |
| if (!done) loadDeferred(); |
| return module[name][p]; |
| }, |
| set: function(o, p, value) { |
| if (!done) loadDeferred(); |
| module[name][p] = value; |
| return true; |
| }, |
| }); |
| }; |
| |
| let _reverseImports = new Map(); |
| |
| // App name to set of libraries that were not only loaded on the page but |
| // also executed. |
| const _executedLibraries = new Map(); |
| self.dart_library.executedLibraryCount = function() { |
| let count = 0; |
| _executedLibraries.forEach(function(executedLibraries, _) { |
| count += executedLibraries.size; |
| }); |
| return count; |
| }; |
| |
| // Library instance that is going to be loaded or has been loaded. |
| class LibraryInstance { |
| constructor(libraryValue) { |
| this.libraryValue = libraryValue; |
| // Cyclic import detection |
| this.loadingState = LibraryLoader.NOT_LOADED; |
| } |
| |
| get isNotLoaded() { |
| return this.loadingState == LibraryLoader.NOT_LOADED; |
| } |
| } |
| |
| class LibraryLoader { |
| constructor(name, defaultLibraryValue, imports, loader, data) { |
| imports.forEach(function(i) { |
| let deps = _reverseImports.get(i); |
| if (!deps) { |
| deps = new Set(); |
| _reverseImports.set(i, deps); |
| } |
| deps.add(name); |
| }); |
| this._name = name; |
| this._defaultLibraryValue = |
| defaultLibraryValue ? defaultLibraryValue : {}; |
| this._imports = imports; |
| this._loader = loader; |
| data.jsSize = loader.toString().length; |
| data.loadStart = NaN; |
| data.loadEnd = NaN; |
| this._metrics = data; |
| |
| // First loaded instance for supporting logic that assumes there is only |
| // one app. |
| // TODO(b/204209941): Remove _firstLibraryInstance after debugger and |
| // metrics support multiple apps. |
| this._firstLibraryInstance = |
| new LibraryInstance(this._deepCopyDefaultValue()); |
| this._firstLibraryInstanceUsed = false; |
| |
| // App name to instance map. |
| this._instanceMap = new Map(); |
| } |
| |
| /// First loaded value for supporting logic that assumes there is only |
| /// one app. |
| get firstLibraryValue() { |
| return this._firstLibraryInstance.libraryValue; |
| } |
| |
| /// The loaded instance value for the given `appName`. |
| libraryValueInApp(appName) { |
| return this._instanceMap.get(appName).libraryValue; |
| } |
| |
| load(appName) { |
| let instance = this._instanceMap.get(appName); |
| if (!instance && !this._firstLibraryInstanceUsed) { |
| // If `_firstLibraryInstance` is already assigned to an app, creates a |
| // new instance clone (with deep copy) and assigns it the given app. |
| // Otherwise, reuse `_firstLibraryInstance`. |
| instance = this._firstLibraryInstance; |
| this._firstLibraryInstanceUsed = true; |
| this._instanceMap.set(appName, instance); |
| } |
| if (!instance) { |
| instance = new LibraryInstance(this._deepCopyDefaultValue()); |
| this._instanceMap.set(appName, instance); |
| } |
| |
| // Check for cycles |
| if (instance.loadingState == LibraryLoader.LOADING) { |
| throwLibraryError('Circular dependence on library: ' + this._name); |
| } else if (instance.loadingState >= LibraryLoader.READY) { |
| return instance.libraryValue; |
| } |
| if (!_executedLibraries.has(appName)) { |
| _executedLibraries.set(appName, new Set()); |
| } |
| _executedLibraries.get(appName).add(this._name); |
| instance.loadingState = LibraryLoader.LOADING; |
| |
| // Handle imports |
| let args = this._loadImports(appName); |
| |
| // Load the library |
| let loader = this; |
| let library = instance.libraryValue; |
| |
| library[libraryImports] = this._imports; |
| library[loadedModule] = library; |
| library[_metrics] = this._metrics; |
| args.unshift(library); |
| |
| if (this._name == 'dart_sdk') { |
| // Eagerly load the SDK. |
| if (!!self.performance && !!self.performance.now) { |
| library[_metrics].loadStart = self.performance.now(); |
| } |
| this._loader.apply(null, args); |
| if (!!self.performance && !!self.performance.now) { |
| library[_metrics].loadEnd = self.performance.now(); |
| } |
| } else { |
| // Load / parse other modules on demand. |
| let done = false; |
| instance.libraryValue = new Proxy(library, { |
| get: function(o, name) { |
| if (name == _metrics) { |
| return o[name]; |
| } |
| if (!done) { |
| done = true; |
| if (!!self.performance && !!self.performance.now) { |
| library[_metrics].loadStart = self.performance.now(); |
| } |
| loader._loader.apply(null, args); |
| if (!!self.performance && !!self.performance.now) { |
| library[_metrics].loadEnd = self.performance.now(); |
| } |
| } |
| return o[name]; |
| } |
| }); |
| } |
| |
| instance.loadingState = LibraryLoader.READY; |
| return instance.libraryValue; |
| } |
| |
| _loadImports(appName) { |
| let results = []; |
| for (let name of this._imports) { |
| results.push(import_(name, appName)); |
| } |
| return results; |
| } |
| |
| _deepCopyDefaultValue() { |
| return JSON.parse(JSON.stringify(this._defaultLibraryValue)); |
| } |
| } |
| LibraryLoader.NOT_LOADED = 0; |
| LibraryLoader.LOADING = 1; |
| LibraryLoader.READY = 2; |
| |
| // Map from name to LibraryLoader |
| let _libraries = new Map(); |
| self.dart_library.libraries = function() { |
| return _libraries.keys(); |
| }; |
| self.dart_library.debuggerLibraries = function() { |
| let debuggerLibraries = []; |
| _libraries.forEach(function(value, key, map) { |
| debuggerLibraries.push(value.load(_firstStartedAppName)); |
| }); |
| Object.setPrototypeOf(debuggerLibraries, null); |
| return debuggerLibraries; |
| }; |
| |
| // Invalidate a library and all things that depend on it |
| function _invalidateLibrary(name) { |
| let lib = _libraries.get(name); |
| if (lib._instanceMap.size === 0) return; |
| lib._firstLibraryInstance = |
| new LibraryInstance(lib._deepCopyDefaultValue()); |
| lib._firstLibraryInstanceUsed = false; |
| lib._instanceMap.clear(); |
| let deps = _reverseImports.get(name); |
| if (!deps) return; |
| deps.forEach(_invalidateLibrary); |
| } |
| |
| function library(name, defaultLibraryValue, imports, loader, data = {}) { |
| let result = _libraries.get(name); |
| if (result) { |
| console.log('Re-loading ' + name); |
| _invalidateLibrary(name); |
| } |
| result = |
| new LibraryLoader(name, defaultLibraryValue, imports, loader, data); |
| _libraries.set(name, result); |
| return result; |
| } |
| self.dart_library.library = library; |
| |
| // Store executed modules upon reload. |
| if (!!self.addEventListener && !!self.localStorage) { |
| self.addEventListener('beforeunload', function(event) { |
| _nameToApp.forEach(function(_, appName) { |
| if (!_executedLibraries.get(appName)) { |
| return; |
| } |
| let libraryCache = { |
| 'time': new Date().getTime(), |
| 'modules': Array.from(_executedLibraries.get(appName).keys()), |
| }; |
| self.localStorage.setItem( |
| `dartLibraryCache:${appName}`, JSON.stringify(libraryCache)); |
| }); |
| }); |
| } |
| |
| // Map from module name to corresponding app to proxy library map. |
| let _proxyLibs = new Map(); |
| |
| function import_(name, appName) { |
| // For backward compatibility. |
| if (!appName && _lastStartedSubapp) { |
| appName = _lastStartedSubapp.appName; |
| } |
| |
| let proxy; |
| if (_proxyLibs.has(name)) { |
| proxy = _proxyLibs.get(name).get(appName); |
| } |
| if (proxy) return proxy; |
| let proxyLib = new Proxy({}, { |
| get: function(o, p) { |
| let lib = _libraries.get(name); |
| if (self.$dartJITModules) { |
| // The backing module changed so update the reference |
| if (!lib) { |
| let xhr = new XMLHttpRequest(); |
| let sourceURL = $dartLoader.moduleIdToUrl.get(name); |
| xhr.open('GET', sourceURL, false); |
| xhr.withCredentials = true; |
| xhr.send(); |
| // Add inline policy to make eval() call Trusted Types compatible |
| // when running in a TT compatible browser |
| let policy = { |
| createScript: function(script) { |
| return script; |
| } |
| }; |
| if (self.trustedTypes && self.trustedTypes.createPolicy) { |
| policy = self.trustedTypes.createPolicy( |
| 'dartDdcModuleLoading#dart_library', policy); |
| } |
| // Append sourceUrl so the resource shows up in the Chrome |
| // console. |
| eval(policy.createScript( |
| xhr.responseText + '//@ sourceURL=' + sourceURL)); |
| lib = _libraries.get(name); |
| } |
| } |
| if (!lib) { |
| throwLibraryError('Module ' + name + ' not loaded in the browser.'); |
| } |
| // Always load the library before accessing a property as it may have |
| // been invalidated. |
| return lib.load(appName)[p]; |
| } |
| }); |
| if (!_proxyLibs.has(name)) { |
| _proxyLibs.set(name, new Map()); |
| } |
| _proxyLibs.get(name).set(appName, proxyLib); |
| return proxyLib; |
| } |
| self.dart_library.import = import_; |
| |
| // Removes the corresponding library and invalidates all things that |
| // depend on it. |
| function _invalidateImport(name) { |
| let lib = _libraries.get(name); |
| if (!lib) return; |
| _invalidateLibrary(name); |
| _libraries.delete(name); |
| } |
| self.dart_library.invalidateImport = _invalidateImport; |
| |
| let _debuggerInitialized = false; |
| |
| // Caches the last N runIds to prevent hot reload requests from the same |
| // runId from executing more than once. |
| const _hotRestartRunIdCache = new Array(); |
| |
| // Called to initiate a hot restart of the application for a given uuid. If |
| // it is not set, the last started application will be hot restarted. |
| // |
| // "Hot restart" means all application state is cleared, the newly compiled |
| // modules are loaded, and `main()` is called. |
| // |
| // Note: `onReloadEnd()` can be provided, and if so will be used instead of |
| // `main()` for hot restart. |
| // |
| // This happens in the following sequence: |
| // |
| // 1. Look for `onReloadStart()` in the same library that has `main()`, and |
| // call it if present. This function is implemented by the application to |
| // ensure any global browser/DOM state is cleared, so the application can |
| // restart. |
| // 2. Wait for `onReloadStart()` to complete (either synchronously, or async |
| // if it returned a `Future`). |
| // 3. Call dart:_runtime's `hotRestart()` function to clear any state that |
| // `dartdevc` is tracking, such as initialized static fields and type |
| // caches. |
| // 4. Call `self.$dartReloadModifiedModules()` (provided by the HTML page) |
| // to reload the relevant JS modules, passing a callback that will invoke |
| // `main()`. |
| // 5. `$dartReloadModifiedModules` calls the callback to rerun main. |
| // |
| async function hotRestart(config) { |
| if (!self || !self.$dartReloadModifiedModules) { |
| console.warn('Hot restart not supported in this environment.'); |
| return; |
| } |
| |
| // If `config.runId` is set (e.g. a unique build ID that represent the |
| // current build and shared by multiple subapps), skip the following runs |
| // with the same id. |
| if (config && config.runId) { |
| if (_hotRestartRunIdCache.indexOf(config.runId) >= 0) { |
| // The run has already started (by other subapp or app) |
| return; |
| } |
| _hotRestartRunIdCache.push(config.runId); |
| |
| // Only cache the runIds for the last N runs. We assume that there are |
| // less than N requests with different runId can happen in a very short |
| // period of time (e.g. 1 second). |
| if (_hotRestartRunIdCache.length > 10) { |
| _hotRestartRunIdCache.shift(); |
| } |
| } |
| |
| self.console.clear(); |
| const sdk = _libraries.get('dart_sdk'); |
| |
| // Finds out what apps and their subapps should be hot restarted in |
| // their starting order. |
| const dirtyAppNames = new Array(); |
| const dirtySubapps = new Array(); |
| if (config && config.runId) { |
| _nameToApp.forEach(function(app, appName) { |
| dirtySubapps.push(...app.uuidToSubapp.values()); |
| dirtyAppNames.push(appName); |
| }); |
| } else { |
| dirtySubapps.push(_lastStartedSubapp); |
| dirtyAppNames.push(_lastStartedSubapp.appName); |
| } |
| |
| // Invokes onReloadStart for each subapp in reversed starting order. |
| const onReloadStartPromises = new Array(); |
| for (const subapp of dirtySubapps.reverse()) { |
| // Call the application's `onReloadStart()` function, if provided. |
| if (subapp.library && subapp.library.onReloadStart) { |
| const result = subapp.library.onReloadStart(); |
| if (result && result.then) { |
| let resolve; |
| onReloadStartPromises.push(new Promise(function(res, _) { |
| resolve = res; |
| })); |
| const dart = sdk.libraryValueInApp(subapp.appName).dart; |
| result.then(dart.dynamic, function() { |
| resolve(); |
| }); |
| } |
| } |
| } |
| // Reverse the subapps back to starting order. |
| dirtySubapps.reverse(); |
| |
| await Promise.all(onReloadStartPromises); |
| |
| // Invokes SDK `hotRestart` to reset all initialized fields and clears |
| // type caches and other temporary data structures used by the |
| // compiler/SDK. |
| for (const appName of dirtyAppNames) { |
| sdk.libraryValueInApp(appName).dart.hotRestart(); |
| } |
| |
| // Invoke `hotRestart` for the deferred loader to clear load ids and |
| // other temporary state. |
| if (self.deferred_loader) { |
| self.deferred_loader.hotRestart(); |
| } |
| |
| // Starts the subapps in their starting order. |
| for (const subapp of dirtySubapps) { |
| // Call the module loader to reload the necessary modules. |
| self.$dartReloadModifiedModules(subapp.appName, function() { |
| // Once the modules are loaded, rerun `main()`. |
| start( |
| subapp.appName, subapp.uuid, subapp.moduleName, |
| subapp.libraryName, true); |
| }); |
| } |
| } |
| self.dart_library.reload = hotRestart; |
| |
| // Creates a script with the proper nonce value for strict CSP or noops on |
| // invalid platforms. |
| self.dart_library.createScript = (function() { |
| // Exit early if we aren't modifying an HtmlElement (such as in D8). |
| if (self.document.createElement == void 0) return; |
| // Find the nonce value. (Note, this is only computed once.) |
| let scripts = Array.from(document.getElementsByTagName('script')); |
| let nonce; |
| scripts.some( |
| script => (nonce = script.nonce || script.getAttribute('nonce'))); |
| // If present, return a closure that automatically appends the nonce. |
| if (nonce) { |
| return function() { |
| let script = document.createElement('script'); |
| script.nonce = nonce; |
| return script; |
| }; |
| } else { |
| return function() { |
| return document.createElement('script'); |
| }; |
| } |
| })(); |
| |
| /// An App contains one or multiple Subapps, all of the subapps share the |
| /// same memory copy of library instances, and as a result they share state |
| /// in Dart statics and top-level fields. There can be one or multiple Apps |
| /// in a browser window, all of the Apps are isolated from each other |
| /// (i.e. they create different instances even for the same module). |
| class App { |
| constructor(name) { |
| this.name = name; |
| |
| // Subapp's uuid to subapps in initial starting order. |
| // (ES6 preserves iteration order) |
| this.uuidToSubapp = new Map(); |
| } |
| } |
| |
| class Subapp { |
| constructor(uuid, appName, moduleName, libraryName, library) { |
| this.uuid = uuid; |
| this.appName = appName; |
| this.moduleName = moduleName; |
| this.libraryName = libraryName; |
| this.library = library; |
| |
| this.originalBody = null; |
| } |
| } |
| |
| // App name to App map in initial starting order. |
| // (ES6 preserves iteration order) |
| const _nameToApp = new Map(); |
| let _firstStartedAppName; |
| let _lastStartedSubapp; |
| |
| /// Starts a subapp that is identified with `uuid`, `moduleName`, and |
| /// `libraryName` inside a parent app that is identified by `appName`. |
| function start(appName, uuid, moduleName, libraryName, isReload) { |
| console.info( |
| `DDC: Subapp Module [${appName}:${moduleName}:${uuid}] is starting`); |
| if (libraryName == null) libraryName = moduleName; |
| const library = import_(moduleName, appName)[libraryName]; |
| |
| let app = _nameToApp.get(appName); |
| if (!isReload) { |
| if (!app) { |
| app = new App(appName); |
| _nameToApp.set(appName, app); |
| } |
| |
| let subapp = app.uuidToSubapp.get(uuid); |
| if (!subapp) { |
| subapp = new Subapp(uuid, appName, moduleName, libraryName, library); |
| app.uuidToSubapp.set(uuid, subapp); |
| } |
| |
| _lastStartedSubapp = subapp; |
| if (!_firstStartedAppName) { |
| _firstStartedAppName = appName; |
| } |
| } |
| |
| const subapp = app.uuidToSubapp.get(uuid); |
| const sdk = import_('dart_sdk', appName); |
| |
| if (!_debuggerInitialized) { |
| // This import is only needed for chrome debugging. We should provide an |
| // option to compile without it. |
| sdk._debugger.registerDevtoolsFormatter(); |
| |
| // Create isolate. |
| _debuggerInitialized = true; |
| } |
| if (isReload) { |
| // subapp may have been modified during reload, `subapp.library` needs |
| // to always point to the latest data. |
| subapp.library = library; |
| |
| if (library.onReloadEnd) { |
| library.onReloadEnd(); |
| return; |
| } else { |
| if (!!self.document) { |
| // Note: we expect originalBody to be undefined in non-browser |
| // environments, but in that case so is the body. |
| if (!subapp.originalBody && !!self.document.body) { |
| self.console.warn('No body saved to update on reload'); |
| } else { |
| self.document.body = subapp.originalBody; |
| } |
| } |
| } |
| } else { |
| // If not a reload and `onReloadEnd` is not defined, store the initial |
| // html to reset it on reload. |
| if (!library.onReloadEnd && !!self.document && !!self.document.body) { |
| subapp.originalBody = self.document.body.cloneNode(true); |
| } |
| } |
| library.main([]); |
| } |
| dart_library.start = start; |
| })(dart_library); |
| } |
| |
| if (!self.deferred_loader) { |
| self.deferred_loader = { |
| // Module IDs already loaded on the page (e.g., during bootstrap or after |
| // loadLibrary is called). |
| loadedModules: new Set(), |
| // An import graph of all direct imports (not deferred). |
| moduleGraph: new Map(), |
| // Maps module IDs to their resolved urls. |
| moduleToUrl: new Map(), |
| // Module IDs mapped to their resolved or resolving promises. |
| moduleToPromise: new Map(), |
| // Deferred libraries on which 'loadLibrary' have already been called. |
| // Load Ids are a composite of the URI of originating load's library and |
| // the target library name. |
| loadIds: new Set(), |
| }; |
| |
| /** |
| * Must be called before 'main' to initialize the deferred loader. |
| * @param {!Map<string, string>} moduleToUrlMapping |
| * @param {!Map<string, !Array<string>>} moduleGraph non-deferred import graph |
| * @param {!Array<string>} loadedModules moduled loaded during bootstrap |
| */ |
| self.deferred_loader.initDeferredLoader = function( |
| moduleToUrlMapping, moduleGraph, loadedModules) { |
| self.deferred_loader.moduleToUrl = moduleToUrlMapping; |
| self.deferred_loader.moduleGraph = moduleGraph; |
| for (let i = 0; i < loadedModules.length; i++) { |
| let module = loadedModules[i]; |
| self.deferred_loader.loadedModules.add(module); |
| self.deferred_loader.moduleToPromise.set(module, Promise.resolve()); |
| } |
| }; |
| |
| /** |
| * Returns all modules downstream of [moduleId] that are visible |
| * (i.e., not deferred) and have not already been loaded. |
| * @param {string} moduleId |
| * @return {!Array<string>} module IDs that must be loaded with [moduleId] |
| */ |
| let dependenciesToLoad = function(moduleId) { |
| let stack = [moduleId]; |
| let seen = new Set(); |
| while (stack.length > 0) { |
| let module = stack.pop(); |
| if (seen.has(module)) continue; |
| seen.add(module); |
| stack = stack.concat(self.deferred_loader.moduleGraph.get(module)); |
| } |
| let dependencies = []; |
| seen.forEach(module => { |
| if (self.deferred_loader.loadedModules.has(module)) return; |
| dependencies.push(module); |
| }); |
| return dependencies; |
| }; |
| |
| /** |
| * Loads [moduleUrl] onto this instance's DDC app's page, then invokes |
| * [onLoad]. |
| * @param {string} moduleUrl |
| * @param {function()} onLoad Callback after a successful load |
| */ |
| let loadScript = function(moduleUrl, onLoad) { |
| // A head element won't be created for D8, so just load synchronously. |
| if (self.document.head == void 0) { |
| self.load(moduleUrl); |
| onLoad(); |
| } |
| let script = dart_library.createScript(); |
| let policy = { |
| createScriptURL: function(src) { |
| return src; |
| } |
| }; |
| if (self.trustedTypes && self.trustedTypes.createPolicy) { |
| policy = self.trustedTypes.createPolicy('dartDdcModuleUrl', policy); |
| } |
| script.setAttribute('src', policy.createScriptURL(moduleUrl)); |
| script.async = false; |
| script.defer = true; |
| script.onload = onLoad; |
| self.document.head.appendChild(script); |
| }; |
| |
| /** |
| * Performs a deferred load, calling [onSuccess] or [onError] callbacks when |
| * the deferred load completes or fails, respectively. |
| * @param {string} loadId {library URI}:{resource name being loaded} |
| * @param {string} targetModule moduleId of the resource requested by [loadId] |
| * @param {function(function())} onSuccess callback after a successful load |
| * @param {function(!Error)} onError callback after a failed load |
| */ |
| self.deferred_loader.loadDeferred = function( |
| loadId, targetModule, onSuccess, onError) { |
| // loadLibrary had already been called, and its module has already been |
| // loaded, so just complete the future. |
| if (self.deferred_loader.loadIds.has(loadId)) { |
| onSuccess(); |
| return; |
| } |
| |
| // The module's been loaded, so mark this import as loaded and finish. |
| if (self.deferred_loader.loadedModules.has(targetModule)) { |
| self.deferred_loader.loadIds.add(loadId); |
| onSuccess(); |
| return; |
| } |
| |
| // The import's module has not been loaded, so load it and its dependencies |
| // before completing the callback. |
| let modulesToLoad = dependenciesToLoad(targetModule); |
| Promise |
| .all(modulesToLoad.map(module => { |
| let url = self.deferred_loader.moduleToUrl.get(module); |
| if (url === void 0) { |
| console.log('Unable to find URL for module: ' + module); |
| return; |
| } |
| let promise = self.deferred_loader.moduleToPromise.get(module); |
| if (promise !== void 0) return promise; |
| self.deferred_loader.moduleToPromise.set( |
| module, |
| new Promise((resolve) => loadScript(url, () => { |
| self.deferred_loader.loadedModules.add(module); |
| resolve(); |
| }))); |
| return self.deferred_loader.moduleToPromise.get(module); |
| })) |
| .then(() => { |
| onSuccess(() => self.deferred_loader.loadIds.add(loadId)); |
| }) |
| .catch((error) => { |
| onError(error.message); |
| }); |
| }; |
| |
| /** |
| * Returns whether or not the module containing [loadId] has finished loading. |
| * @param {string} loadId library URI concatenated with the resource being |
| * loaded |
| * @return {boolean} |
| */ |
| self.deferred_loader.isLoaded = function(loadId) { |
| return self.deferred_loader.loadIds.has(loadId); |
| }; |
| |
| /** |
| * Removes references to [moduleId] in the deferred loader. |
| * @param {string} moduleId |
| * |
| * TODO(markzipan): Determine how deep we should clear moduleId's references. |
| */ |
| self.deferred_loader.clearModule = function(moduleId) { |
| self.deferred_loader.loadedModules.delete(moduleId); |
| self.deferred_loader.moduleToUrl.delete(moduleId); |
| self.deferred_loader.moduleToPromise.delete(moduleId); |
| }; |
| |
| /** |
| * Clears state required for hot restart. |
| */ |
| self.deferred_loader.hotRestart = function() { |
| self.deferred_loader.loadIds = new Set(); |
| }; |
| } |
