Angular语言 - 在转发请求之前等待刷新令牌函数完成

Question

我正在angular中与django后端使用jwt进行验证系统。我有一个角拦截器，它在每个请求中检查访问令牌是否仍然有效，如果无效，它调用refreshtoken函数并刷新访问令牌。

下面是拦截器的代码:

constructor(private authService:AuthService) {}
intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
let access_token = localStorage.getItem("access_token");

if(access_token){
// Check if access token is no longer valid, if so, refresh it with the refresh token
if(this.authService.isLoggedOut()){

this.authService.refreshToken();
access_token = localStorage.getItem("access_token");
}
const cloned = request.clone({
headers: request.headers.set("Authorization", "Bearer " + access_token)
});
return next.handle(cloned);
} 
else{
return next.handle(request);
}

它获得access_token并在验证服务的帮助下检查其有效性。我的问题是，如果它无效，它调用refreshToken()函数，看起来像这样，

refreshToken(){
let refresh_token = localStorage.getItem("refresh_token");
console.log("BEFORE REFRESH: " + localStorage.getItem("access_token"));

return this.http.post(`${apiUrl}token/refresh/`, {"refresh" : refresh_token}).subscribe(res => {
let access_token = res["access"]
const expiresAt = this.tokenExpiresAt(access_token);
localStorage.setItem("access_token", access_token);
localStorage.setItem("expires_at", JSON.stringify(expiresAt.valueOf()));
console.log("AFTER REFRESH: " + localStorage.getItem("access_token"));
});
}

，但它不等待刷新令牌函数完成并返回句柄。因此，使用无效令牌的第一个请求将抛出错误，只有下一个请求才可以。

我如何修改这个等待refreshToken()完成?

谢谢你的时间!

Answer 1

您可以使用rxjs操作符，例如switchMap

intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
let access_token = localStorage.getItem("access_token");
if (access_token) {
// Check if access token is no longer valid, if so, refresh it with the refresh token
if (this.authService.isLoggedOut()) {
return this.authService.refreshToken().pipe(
switchMap(token => {
const cloned = request.clone({
headers: request.headers.set("Authorization", "Bearer " + access_token)
});
return next.handle(cloned);
})
)
}
} else {
return next.handle(request);
}
}

和refreshToken函数-使其返回Observsble，并将localStorage设置在pipe

refreshToken(){
let refresh_token = localStorage.getItem("refresh_token");
console.log("BEFORE REFRESH: " + localStorage.getItem("access_token"));
return this.http.post(`${apiUrl}token/refresh/`, {"refresh" : refresh_token}).pipe(tap(res => {
let access_token = res["access"]
const expiresAt = this.tokenExpiresAt(access_token);
localStorage.setItem("access_token", access_token);
localStorage.setItem("expires_at", JSON.stringify(expiresAt.valueOf()));
console.log("AFTER REFRESH: " + localStorage.getItem("access_token"));
});
)
}

Answer 2

我综合了多个问题的答案，最终得出了这样一个解决方案:

拦截:

intercept(request: HttpRequest<unknown>, next: HttpHandler): Observable<HttpEvent<unknown>> {
let access_token = localStorage.getItem("access_token");

if (access_token) {
// Check if access token is no longer valid, if so, refresh it with the refresh token
if (this.authService.isLoggedOut()) {
return from(this.authService.refreshToken()).pipe(
mergeMap((access_token) => {
localStorage.setItem("access_token", access_token);
const cloned = request.clone({
headers: request.headers.set("Authorization", "Bearer " + access_token),
});
return next.handle(cloned);
})
);
}
const cloned = request.clone({
headers: request.headers.set("Authorization", "Bearer " + access_token),
});
return next.handle(cloned);
} else {
return next.handle(request);
}
}

refreshToken:

async refreshToken(): Promise<string> {
let refresh_token = localStorage.getItem("refresh_token"); 
const res$ = this.http
.post(`${apiUrl}token/refresh/`, { refresh: refresh_token })
.pipe(map((res) => res["access"]))
.pipe(first());
const res = await lastValueFrom(res$);
const expiresAt = this.tokenExpiresAt(res);
localStorage.setItem("access_token", res);
localStorage.setItem("expires_at", JSON.stringify(expiresAt.valueOf()));
console.log("Refreshed Access Token");
return res;
}