我需要在用户登录后为每个后续请求设置一些授权头。
为特定请求设置头信息，
import {Headers} from 'angular2/http';
var headers = new Headers();
headers.append(headerName, value);
// HTTP POST using these headers
this.http.post(url, data, {
headers: headers
})
// do something with the response
参考
但是，以这种方式为每个请求手动设置请求头是不可行的。
我如何设置头设置一旦用户登录，也删除注销这些头?
当前回答
在Angular 2.1.2中，我通过扩展Angular Http来解决这个问题:
import {Injectable} from "@angular/core";
import {Http, Headers, RequestOptionsArgs, Request, Response, ConnectionBackend, RequestOptions} from "@angular/http";
import {Observable} from 'rxjs/Observable';
@Injectable()
export class HttpClient extends Http {
constructor(protected _backend: ConnectionBackend, protected _defaultOptions: RequestOptions) {
super(_backend, _defaultOptions);
}
_setCustomHeaders(options?: RequestOptionsArgs):RequestOptionsArgs{
if(!options) {
options = new RequestOptions({});
}
if(localStorage.getItem("id_token")) {
if (!options.headers) {
options.headers = new Headers();
}
options.headers.set("Authorization", localStorage.getItem("id_token"))
}
return options;
}
request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
options = this._setCustomHeaders(options);
return super.request(url, options)
}
}
然后在我的应用程序提供者中，我可以使用自定义工厂来提供“Http”
import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';
import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';//above snippet
function httpClientFactory(xhrBackend: XHRBackend, requestOptions: RequestOptions): Http {
return new HttpClient(xhrBackend, requestOptions);
}
@NgModule({
imports:[
FormsModule,
BrowserModule,
],
declarations: APP_DECLARATIONS,
bootstrap:[AppComponent],
providers:[
{ provide: Http, useFactory: httpClientFactory, deps: [XHRBackend, RequestOptions]}
],
})
export class AppModule {
constructor(){
}
}
现在我不需要声明每个Http方法，可以在整个应用程序中正常使用Http。
其他回答
以下是已接受答案的改进版本，针对Angular2 final进行了更新:
import {Injectable} from "@angular/core";
import {Http, Headers, Response, Request, BaseRequestOptions, RequestMethod} from "@angular/http";
import {I18nService} from "../lang-picker/i18n.service";
import {Observable} from "rxjs";
@Injectable()
export class HttpClient {
constructor(private http: Http, private i18n: I18nService ) {}
get(url:string):Observable<Response> {
return this.request(url, RequestMethod.Get);
}
post(url:string, body:any) {
return this.request(url, RequestMethod.Post, body);
}
private request(url:string, method:RequestMethod, body?:any):Observable<Response>{
let headers = new Headers();
this.createAcceptLanguageHeader(headers);
let options = new BaseRequestOptions();
options.headers = headers;
options.url = url;
options.method = method;
options.body = body;
options.withCredentials = true;
let request = new Request(options);
return this.http.request(request);
}
// set the accept-language header using the value from i18n service that holds the language currently selected by the user
private createAcceptLanguageHeader(headers:Headers) {
headers.append('Accept-Language', this.i18n.getCurrentLang());
}
}
当然，如果需要的话，它应该扩展为delete和put等方法(在我的项目中，目前还不需要它们)。
优点是在get/post/…中有较少的重复代码。方法。
注意，在我的例子中，我使用cookie进行身份验证。我需要i18n的报头(Accept-Language报头)，因为我们的API返回的许多值都是用用户的语言翻译的。在我的应用程序中，i18n服务保存用户当前选择的语言。
在Angular 2.1.2中，我通过扩展Angular Http来解决这个问题:
import {Injectable} from "@angular/core";
import {Http, Headers, RequestOptionsArgs, Request, Response, ConnectionBackend, RequestOptions} from "@angular/http";
import {Observable} from 'rxjs/Observable';
@Injectable()
export class HttpClient extends Http {
constructor(protected _backend: ConnectionBackend, protected _defaultOptions: RequestOptions) {
super(_backend, _defaultOptions);
}
_setCustomHeaders(options?: RequestOptionsArgs):RequestOptionsArgs{
if(!options) {
options = new RequestOptions({});
}
if(localStorage.getItem("id_token")) {
if (!options.headers) {
options.headers = new Headers();
}
options.headers.set("Authorization", localStorage.getItem("id_token"))
}
return options;
}
request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
options = this._setCustomHeaders(options);
return super.request(url, options)
}
}
然后在我的应用程序提供者中，我可以使用自定义工厂来提供“Http”
import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';
import { RequestOptions, Http, XHRBackend} from '@angular/http';
import {HttpClient} from './httpClient';//above snippet
function httpClientFactory(xhrBackend: XHRBackend, requestOptions: RequestOptions): Http {
return new HttpClient(xhrBackend, requestOptions);
}
@NgModule({
imports:[
FormsModule,
BrowserModule,
],
declarations: APP_DECLARATIONS,
bootstrap:[AppComponent],
providers:[
{ provide: Http, useFactory: httpClientFactory, deps: [XHRBackend, RequestOptions]}
],
})
export class AppModule {
constructor(){
}
}
现在我不需要声明每个Http方法，可以在整个应用程序中正常使用Http。
对于Angular 5及以上版本，我们可以使用HttpInterceptor泛化请求和响应操作。 这有助于我们避免重复:
1)通用报头
2)指定响应类型
3)查询请求
import { Injectable } from '@angular/core';
import {
HttpRequest,
HttpHandler,
HttpEvent,
HttpInterceptor,
HttpResponse,
HttpErrorResponse
} from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/do';
@Injectable()
export class AuthHttpInterceptor implements HttpInterceptor {
requestCounter: number = 0;
constructor() {
}
intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
request = request.clone({
responseType: 'json',
setHeaders: {
Authorization: `Bearer token_value`,
'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'
}
});
return next.handle(request).do((event: HttpEvent<any>) => {
if (event instanceof HttpResponse) {
// do stuff with response if you want
}
}, (err: any) => {
if (err instanceof HttpErrorResponse) {
// do stuff with response error if you want
}
});
}
}
我们可以使用这个AuthHttpInterceptor类作为HttpInterceptors的提供者:
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
import { AppRoutingModule } from './app.routing-module';
import { AuthHttpInterceptor } from './services/auth-http.interceptor';
import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
AppRoutingModule,
HttpClientModule,
BrowserAnimationsModule,
],
providers: [
{
provide: HTTP_INTERCEPTORS,
useClass: AuthHttpInterceptor,
multi: true
}
],
exports: [],
bootstrap: [AppComponent]
})
export class AppModule {
}
像下面这样保持独立的服务怎么样
import {Injectable} from '@angular/core';
import {Headers, Http, RequestOptions} from '@angular/http';
@Injectable()
export class HttpClientService extends RequestOptions {
constructor(private requestOptionArgs:RequestOptions) {
super();
}
addHeader(headerName: string, headerValue: string ){
(this.requestOptionArgs.headers as Headers).set(headerName, headerValue);
}
}
当你从另一个地方调用这个时，使用this. httpclientservice。addHeader("Authorization"， " holder " + this.tok);
您将看到添加的标题，例如:-授权如下
从Angular 4.3开始，HTTP拦截器现在可以通过新的HttpClient @angular/common/ HTTP使用了。X版本及更高版本。
现在为每个请求添加头文件非常简单:
import {
HttpEvent,
HttpInterceptor,
HttpHandler,
HttpRequest,
} from '@angular/common/http';
import { Observable } from 'rxjs';
import { Injectable } from '@angular/core';
@Injectable()
export class AddHeaderInterceptor implements HttpInterceptor {
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
// Clone the request to add the new header
const clonedRequest = req.clone({ headers: req.headers.append('Authorization', 'Bearer 123') });
// Pass the cloned request instead of the original request to the next handle
return next.handle(clonedRequest);
}
}
有一个不可变性的原则，这就是为什么在设置新内容之前需要克隆请求。
由于编辑头部是一个非常常见的任务，实际上有一个快捷方式(在克隆请求时):
const clonedRequest = req.clone({ setHeaders: { Authorization: 'Bearer 123' } });
创建拦截器之后，你应该使用HTTP_INTERCEPTORS提供的方法注册它。
import { HTTP_INTERCEPTORS } from '@angular/common/http';
@NgModule({
providers: [{
provide: HTTP_INTERCEPTORS,
useClass: AddHeaderInterceptor,
multi: true,
}],
})
export class AppModule {}
