我正在使用基于令牌的身份验证,并且令牌已保存在数据库中.
当应用程序启动时,我需要从数据库中获取令牌并在进行API调用之前使其可用.
什么是最好的方法：
在组件中：
ngOnit() {
storage.get('token').then((val) => {
Make api call here
});
}
或者在共享服务中：
getToken() {
return Promise((resolve,reject)=>{
#if fetched once save in local var and resolve token
#or fetch from DB and resolve token
})
}
// On Component
this.sharedService.getToken().then((token)=>{
//Make api call
}
有没有什么办法可以确保在加载视图之前获取DB令牌并存储在共享服务中？ storage.get是’ES6承诺’
关注是在加载视图升级到任何引导事件之前加载令牌的责任,因此不需要在每个组件中定义onViewLoad.
我已经以这种方式实现了上述用例.
我已经为CRUD创建了ApiService,如下所示.该代码不言自明,如果您需要更多信息,请告诉我们.
API-service.ts
import { Injectable,} from '@angular/core';
import { Http,Response } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import { Headers,RequestOptions,BaseRequestOptions } from '@angular/http';
import { Storage } from '@ionic/storage';
import { Events } from 'ionic-angular';
@Injectable()
export class ApiService {
constructor(private http: Http,private storage: Storage,private events: Events) { }
createHeader(headers: Headers) {
return new Promise((resolve,reject) => {
this.storage.get('loggedInUser')
.then((token: any) => {
if (token) headers.append('Authorization','token ' + token.token);
resolve(headers);
},err => {
resolve(headers);
});
});
}
get(api) {
let header = new Headers();
return Observable.fromPromise(this.createHeader(header))
.map(() => {
let options = new BaseRequestOptions();
options.withCredentials = true;
options.headers = header;
return options
})
.switchMap((options) => this.http.get(api,options))
.catch((err: Error | Response) => {
if (err instanceof Response && err.status === 401) {
this.events.publish('token-expiration');
}
return Observable.throw(err);
});
}
post(url,params): Observable<any> {
return new Observable(observer => {
let header = new Headers();
this.createHeader(header)
.then(() => {
let options = new RequestOptions({ headers: header });
this.http.post(url,params,options)
.subscribe(response => {
observer.next(response);
observer.complete();
},(e) => {
observer.error(e);
});
})
})
}
delete(url) {
return new Observable(observer => {
let header = new Headers();
this.createHeader(header)
.then(() => {
return this.http.delete(url,{ headers: header,withCredentials: true })
.subscribe(response => {
observer.next(response);
observer.complete();
});
})
});
}
}
在这里,我在用户登录app时创建了loggedInUser存储.它也是一个提供者,如下所示.
社会login.ts
import { Injectable } from '@angular/core';
import { ApiService } from "../providers";
import { LocalCacheServiceProvider } from "../local-cache-service/local-cache-service";
import { UserService } from "../user-provider";
import { Storage } from '@ionic/storage';
@Injectable()
export class SocialLoginProvider {
constructor(private apiService: ApiService,private localCacheService: LocalCacheServiceProvider,private userService: UserService,private storage: Storage) {
}
//login To App
loginToApp(url: string,data: string) {
this.apiService.post(url,{ access_token: data })
.map((res: any) => res.json())
.subscribe(res => {
this.setUserLocally(res);
});
}
//set User Locally
setUserLocally(user) {
this.localCacheService.clearAllKeys().then(() => {
this.userService.setLoggedInUser(user);
this.storage.set('loggedInUser',user);
});
}
}
之后,我可以通过我的任何提供程序(用于CRUD操作)使用上述服务(即ApiService),如下所示.
这是ArticleService.
文章-service.ts
import { Injectable } from '@angular/core';
import { Observable } from "rxjs/Observable";
import 'rxjs/add/operator/map';
import { config } from '../config/config';
import { ApiService } from './api-service';
@Injectable()
export class ArticleService {
constructor(private apiService: ApiService) {
}
getBookById(id) {
return this.apiService.get(`${config.getBookById}${id}/`).map((res: any) => res.json());
}
}
