Angular Universal TransferState未在客户端上加载

Question

Angular Universal TransferState未在客户端上加载

Joh*_*ohn 6 apollo angular-universal angular angular5

我正在尝试使用TransferState我的Angular Universal v5应用程序.经过大量的调试后,我意识到,在服务器上,TransferState似乎正在工作,因为响应包含一个<script id=APP_ID></script>包含相应序列化状态(TransferState源)的标记.

出于某种原因,浏览器应用程序尚未使用状态进行初始化.如果我将测试状态硬编码到我的应用程序index.html文件中(通过复制和粘贴),那么我的浏览器应用程序已成功初始化为浏览器状态.我不确定出了什么问题.任何想法非常感谢!

我唯一的猜测是,当我在Chrome的检查器中观看我的应用程序加载时,看起来好像大多数元素一次加载,然后在另一个时间点<script id=APP_ID></script>显示.这似乎暗示脚本标签是以某种方式在浏览器端生成/处理的,即使我已经检查了服务器的响应并且它包含脚本标记.但是,如果脚本标记在客户端进行某种处理,则可能TransferState在处理完成之前进行初始化,这就是我的应用程序未接收状态的原因.再次,任何想法都非常感谢!

这是相关代码:

`app.module.ts`

import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
import { BrowserModule, BrowserTransferStateModule } from '@angular/platform-browser';
import { environment } from '../environments/environment';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';    
import { AppRoutingModule } from './app-routing.module';
import { GraphQLModule } from './graphql.module';

@NgModule({
  imports: [
    BrowserModule.withServerTransition({ appId: 'service-work-coordination' }),
    BrowserTransferStateModule,
    AppRoutingModule,
    GraphQLModule,
  ],
  declarations: [AppComponent],
  bootstrap: [AppComponent],
})
export class AppModule {}

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`app.server.module.ts`

import { NgModule } from '@angular/core';
import { ServerModule, ServerTransferStateModule } from '@angular/platform-server';
import { ModuleMapLoaderModule } from '@nguniversal/module-map-ngfactory-loader';

import { AppModule } from './app.module';
import { AppComponent } from './app.component';

@NgModule({
  imports: [
    AppModule,
    ServerModule,
    ServerTransferStateModule,
    ModuleMapLoaderModule, // <-- *Important* to have lazy-loaded routes work
  ],
  // Since the bootstrapped component is not inherited from your
  // imported AppModule, it needs to be repeated here.
  bootstrap: [AppComponent],
})
export class AppServerModule {}

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`graphql.module.ts`

import { NgModule, APP_ID, PLATFORM_ID, Inject } from '@angular/core';
import { TransferState, makeStateKey } from '@angular/platform-browser';
import { HttpClientModule, HttpHeaders } from '@angular/common/http';
import { environment } from '../environments/environment';

// Apollo
import { ApolloModule, Apollo } from 'apollo-angular';
import { HttpLinkModule, HttpLink, HttpLinkHandler } from 'apollo-angular-link-http';
import { InMemoryCache, NormalizedCache, NormalizedCacheObject } from 'apollo-cache-inmemory';
import { setContext } from 'apollo-link-context';
import { isPlatformBrowser } from '@angular/common';

const uri = environment.uris.api.graphql;

const STATE_KEY = makeStateKey<any>('apollo.state');

@NgModule({
  imports: [
    HttpClientModule,
    ApolloModule,
    HttpLinkModule,
  ],
  exports: [
    HttpClientModule,
    ApolloModule,
    HttpLinkModule,
  ]
})
export class GraphQLModule {
  private cache: InMemoryCache;
  private link: HttpLinkHandler;

  constructor(
    private apollo: Apollo,
    private transferState: TransferState,
    private httpLink: HttpLink,
    @Inject(PLATFORM_ID) private platformId: any,
  ) {
    this.cache = new InMemoryCache();
    this.link = this.httpLink.create({ uri });

    console.log('transferState: ', this.transferState);

    const isBrowser = this.transferState.hasKey<NormalizedCache>(STATE_KEY);

    if (isPlatformBrowser(this.platformId)) {
      this.apollo.create({
        link: this.link,
        cache: this.cache,
        ssrForceFetchDelay: 100,
      });

      this.onBrowser();      
    } else {      
      this.apollo.create({
        link: this.link,
        cache: this.cache,
        ssrMode: true,
      });

      this.onServer();      
    }
  }

  onServer(): void {
    this.transferState.onSerialize(STATE_KEY, () => this.cache.extract());
  }

  onBrowser(): void {
    const state = this.transferState.get<NormalizedCacheObject | null>(STATE_KEY, null);

    if (state) {
      this.cache.restore(state);      
    }
  }
}

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简化的服务器响应

<html>
<head>...app code...</head>
<body>
<app-root>...app code...</app-root>
<script type="text/javascript" src="inline.6ce41075b82d3dba433b.bundle.js"></script>
<script type="text/javascript" src="polyfills.37cc021a2888e752595b.bundle.js"></script>
<script type="text/javascript" src="main.1efdc21cec25daa396d1.bundle.js"></script>
<script id="service-work-coordination-state" type="application/json">{&q;apollo.state&q;:{&q;$ROOT_QUERY.person({\&q;id\&q;:\&q;074a9421-53bb-44c7-8afe-43130c723bd9\&q;})&q;:{&q;firstName&q;:&q;John&q;,&q;middleName&q;:null,&q;lastName&q;:&q;Carroll&q;,&q;primaryEmailAddress&q;:&q;:`EmailAddress::Person::Current`:`EmailAddress::Person`:`EmailAddress::Current`:`EmailAddress`:`Current` {uuid: &s;f0c4896a-27da-410b-84d3-3d66e1507a7e&s;}&q;,&q;__typename&q;:&q;Person&q;},&q;ROOT_QUERY&q;:{&q;person({\&q;id\&q;:\&q;074a9421-53bb-44c7-8afe-43130c723bd9\&q;})&q;:{&q;type&q;:&q;id&q;,&q;id&q;:&q;$ROOT_QUERY.person({\&q;id\&q;:\&q;074a9421-53bb-44c7-8afe-43130c723bd9\&q;})&q;,&q;generated&q;:true}}}}</script>
</body>
</html>

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Answer 1

Joh*_*ohn 20

Uggg ......事实证明,我已经遇到了Angular中一个已知(谢天谢地)的错误.TransferState在客户端上的,而脚本标签被处理/加载以某种方式被启动.为了解决这个问题,目前您需要延迟角度客户端应用程序的引导.

更新 `main.ts`

document.addEventListener('DOMContentLoaded', () => {
  platformBrowserDynamic()
  .bootstrapModule(AppModule)
});

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非常感谢，你救了我的一天！我想知道为什么 Angular 团队没有在他们的官方文档（https://angular.io/api/platform-browser/TransferState）中包含这些信息。 (2认同)
我使用 CLI 添加了 SSR 支持到我的应用程序，但它有这个问题，我花了大约 3 天的时间才意识到问题是什么。感谢这个有用的答案 (2认同)

归档时间：	7 年，11 月前
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Angular Universal TransferState未在客户端上加载

app.module.ts

app.server.module.ts

graphql.module.ts

简化的服务器响应

更新 main.ts

`app.module.ts`

`app.server.module.ts`

`graphql.module.ts`

更新 `main.ts`