我的问题类似于DI with cyclic dependency with custom HTTP and ConfigService，但不完全相同，为此问题提供的解决方案并不能解决我的问题。
我正在使用httpInterceptor，并且还需要configService在运行时提取环境信息。这是它的样子：
//app.module.ts
import { BrowserModule } from '@angular/platform-browser';
import { NgModule, APP_INITIALIZER, Injector } from '@angular/core';
import { Router } from '@angular/router';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { HttpModule, Http, Request, RequestOptionsArgs, Response, XHRBackend, RequestOptions, ConnectionBackend, Headers } from '@angular/http';
import { CacheService, CacheStoragesEnum } from 'ng2-cache/ng2-cache';
import { AppConfig } from './app.config';
import { AppComponent } from './app.component';
import { HttpInterceptorService} from './services/http-interceptor/http-interceptor.service';
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
FormsModule,
HttpModule,
routing,
ReactiveFormsModule
],
providers: [
CacheService,
AppConfig,
{ provide: APP_INITIALIZER, useFactory: (config: AppConfig) => config.load(), deps: [AppConfig]},
{ provide: Http, useFactory: (backend: ConnectionBackend, defaultOptions: RequestOptions, router: Router, cacheService: CacheService, appConfig: AppConfig) => return new HttpInterceptorService(backend, defaultOptions, router, cacheService, appConfig), deps: [XHRBackend, RequestOptions, Router, CacheService, AppConfig]}
],
bootstrap: [AppComponent]
})
export class AppModule { }
app.config.ts
//app.config.ts
import { Inject, Injectable, Injector } from '@angular/core';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Rx';
@Injectable()
export class AppConfig {
private config: Object = null;
private env: Object = null;
private http: Http;
constructor(private injector : Injector) {
setTimeout(() => {
console.log('initialize http in appConfig');
this.http = this.injector.get(Http);
});
}
/**
* Use to get the data found in the second file (config file)
*/
public getConfig(key: any) {
return this.config[key];
}
/**
* Use to get the data found in the first file (env file)
*/
public getEnv(key: any) {
return this.env[key];
}
/**
* This method:
* a) Loads "env.json" to get the current working environment (e.g.: 'production', 'development')
* b) Loads "config.[env].json" to get all env's variables (e.g.: 'config.development.json')
*/
public load() {
console.log('---------------------- in appConfig load method --------------------');
return new Promise((resolve, reject) => {
this.http.get('app/env.json').map( res => res.json() ).catch((error: any):any => {
console.log('Configuration file "env.json" could not be read');
resolve(true);
return Observable.throw(error.json().error || 'Server error');
}).subscribe( (envResponse) => {
this.env = envResponse;
console.log('-------------------------------------------------');
console.log(envResponse);
let request:any = null;
switch (envResponse['env']) {
case 'production': {
request = this.http.get('app/config.' + envResponse['env'] + '.json');
} break;
case 'test': {
request = this.http.get('app/config.' + envResponse['env'] + '.json');
} break;
case 'default': {
console.error('Environment file is not set or invalid');
resolve(true);
} break;
}
if (request) {
request
.map( res => res.json() )
.catch((error: any) => {
console.error('Error reading ' + envResponse['env'] + ' configuration file');
resolve(error);
return Observable.throw(error.json().error || 'Server error');
})
.subscribe((responseData) => {
this.config = responseData;
resolve(true);
});
} else {
console.error('Env config file "env.json" is not valid');
resolve(true);
}
});
});
}
}
这里是拦截器
//http-interceptor.service.ts
import {Http, Request, RequestOptionsArgs, Response, XHRBackend, RequestOptions, URLSearchParams,ConnectionBackend, Headers} from '@angular/http';
import {Router} from '@angular/router';
import { Observable } from 'rxjs/Observable';
import {CacheService, CacheStoragesEnum} from 'ng2-cache/ng2-cache';
import { AppConfig } from '../../app.config';
const TOKEN_EXPIRY = '1440';
const CACHE_EXPIRY = 10 * 60 * 1000;
const CACHE_RECYCLE = 4 * 60 * 1000;
export class HttpInterceptorService extends Http {
private webUrl : string;
private serviceUrl : string;
constructor(backend: ConnectionBackend,
defaultOptions: RequestOptions,
private _router: Router,
private _cacheService: CacheService,
private config: AppConfig) {
super(backend, defaultOptions);
this._cacheService = this._cacheService.useStorage(CacheStoragesEnum.LOCAL_STORAGE);
}
request(url: string | Request, options?: RequestOptionsArgs): Observable<Response> {
return this.getToken(url).flatMap(tokenRecord =>super.request(url, this.getRequestOptionArgs(tokenRecord, options)));
}
get(url: string, options?: RequestOptionsArgs): Observable<Response> {
return this.getToken(url).flatMap(tokenRecord => super.get(url, this.getRequestOptionArgs(tokenRecord, options)))
}
post(url: string, body: string, options?: RequestOptionsArgs): Observable<Response> {
return this.getToken(url).flatMap(tokenRecord => super.post(url, body, this.getRequestOptionArgs(tokenRecord, options)))
}
put(url: string, body: any, options?: RequestOptionsArgs): Observable<Response> {
return this.getToken(url).flatMap(tokenRecord => super.put(url, body, this.getRequestOptionArgs(tokenRecord, options)));
}
delete(url: string, options?: RequestOptionsArgs): Observable<Response> {
return this.getToken(url).flatMap(tokenRecord => super.delete(url, this.getRequestOptionArgs(tokenRecord, options)));
}
getRequestOptionArgs(tokenRecord, options?: RequestOptionsArgs) : RequestOptionsArgs {
if (options == null) {
options = new RequestOptions();
}
if (options.headers == null) {
options.headers = new Headers();
}
options.headers.append('Content-Type', 'application/json');
options.headers.append('Authorization', tokenRecord.token);
return options;
}
getToken (url) {
let domain;
this.webUrl = this.config.getConfig('webUrl');
this.serviceUrl = this.config.getConfig('serviceUrl');
if (this.serviceUrl.indexOf("://") > -1) {
domain = this.serviceUrl.split('/')[2];
} else {
domain = this.serviceUrl.split('/')[0];
}
domain = domain.split(':')[0];
let serviceHost = domain;
let headers = new Headers();
headers.append('Accept', 'application/json, text/plain, */*');
let params = new URLSearchParams();
params.append('service', serviceHost);
params.append('expiry', TOKEN_EXPIRY);
let options = new RequestOptions({ headers:headers, search:params, withCredentials:true });
let cacheName = "webCache";
let cacheKeyBase = "/token";
let cacheKey = cacheKeyBase + "/" + serviceHost;
let existingCache = this._cacheService.get(cacheKey);
if(existingCache) {
return Observable.of(existingCache);
}
return super.get(this.webUrl+'/a/token', options)
.map((response:Response) => {
response = response.json();
let tokenType = response['tokenType'];
let tokenVal = response['access_token'];
let token = tokenType + " " + tokenVal;
let tokenRecord = {
token:token,
tokenType:response['tokenType'],
expiresAt: new Date(response['expires_at'] * 1000),
expiresIn: response['expires_in'],
aquiredOn: new Date()
};
this._cacheService.set(cacheKey, tokenRecord, {maxAge: CACHE_EXPIRY});
return tokenRecord;
}).catch(this.handleError);
}
private handleError(error:Response){
return Observable.throw(error || 'Server error');
}
}
这是我得到的错误
Unhandled Promise rejection: Cannot read property 'componentTypes' of undefined ; Zone: <root> ; Task: Promise.then ; Value: TypeError: Cannot read property 'componentTypes' of undefined(…) TypeError: Cannot read property 'componentTypes' of undefined
at setupRouter
如果我需要提供更多信息，请与我们联系。
答案 0 :(得分：1)
我找到了解决问题的方法，这是我如何注入appConfig
import { BrowserModule } from '@angular/platform-browser';
import { NgModule, APP_INITIALIZER, Injector } from '@angular/core';
import { Router } from '@angular/router';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { HttpModule, Http, Request, RequestOptionsArgs, Response, XHRBackend, RequestOptions, ConnectionBackend, Headers } from '@angular/http';
import { CacheService, CacheStoragesEnum } from 'ng2-cache/ng2-cache';
import { AppConfig } from './app.config';
import { AppComponent } from './app.component';
import { HttpInterceptorService} from './services/http-interceptor/http-interceptor.service';
export function createAppModule(conf) {
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
FormsModule,
HttpModule,
routing,
ReactiveFormsModule
],
providers: [
CacheService,
{ provide: Config, useValue: conf },
{
provide: AppConfig,
useFactory: (_config: Config) => {
return new AppConfig(_config);
}, deps: [Config]
},
{ provide: Http, useFactory: (backend: ConnectionBackend, defaultOptions: RequestOptions, router: Router, cacheService: CacheService, appConfig: AppConfig) => return new HttpInterceptorService(backend, defaultOptions, router, cacheService, appConfig), deps: [XHRBackend, RequestOptions, Router, CacheService, AppConfig]}
],
bootstrap: [AppComponent]
})
class AppModule { }
return AppModule;
}
我在main.ts中进行了更改以使用AppModule并拉动config.json，这里看起来像是
import './polyfills.ts';
import { ReflectiveInjector, Injectable, OpaqueToken, Injector, NgModule, enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import {
Http, CookieXSRFStrategy, XSRFStrategy, RequestOptions, BaseRequestOptions,
ResponseOptions, BaseResponseOptions, XHRBackend, BrowserXhr, Response
} from '@angular/http';
import { createAppModule } from './app/app.module';
function getHttp(): Http {
let providers = [
{
provide: Http, useFactory: (backend: XHRBackend, options: RequestOptions) => {
return new Http(backend, options);
},
deps: [XHRBackend, RequestOptions]
},
BrowserXhr,
{ provide: RequestOptions, useClass: BaseRequestOptions },
{ provide: ResponseOptions, useClass: BaseResponseOptions },
XHRBackend
];
return ReflectiveInjector.resolveAndCreate(providers).get(Http);
}
getHttp().get('/assets/config.json').toPromise()
.then((res: Response) => {
let conf = res.json();
platformBrowserDynamic().bootstrapModule(createAppModule(conf));
})
.catch(error => { console.error(error) });
可能有更好的方法可以做到这一点，但我发现这对我有用，但是任何人都有更好的方法和任何建议，请提供您的意见。