Angular http 拦截器

Angular http的拦截器一般用来处理每个http都需要添加的参数或者是统一处理错误信息

Angular1.x的http拦截器处理：

 $httpProvider.interceptors.push(function ($q) {
                return {
                    request: function (config) {

                        var url = config.url;

                        //这个token表示是在登录状态, 不要用在header中，options无法设置header
                        if(TASApp["x-auth-token"]){
                            if(url.indexOf("?") == -1){
                                url+="?x-auth-token="+TASApp["x-auth-token"];
                            }else{
                                url+="&x-auth-token="+TASApp["x-auth-token"];
                            }
                        }

                        config.url = url;

                        return config || $q.reject(config);
                    },

                    response: function (res) {
                        //统一处理返回信息，如果是错误则在这里统一处理，注意如果这样处理错误(reject)，那么所有的错误信息会进入http的error回调，在success里默认就是成功，都可以不判断data.success
                        if (res.data.success == false) {
                            TASApp.ajaxReturnErrorHandler(res.data["info"]); //TASApp是一个constant对象
                            return $q.reject(res.data); //will go to error callback
                        } else if (res.data.success == "relogin") {
                            TASApp.relogin();
                            return $q.reject(res.data); //will go to error callback
                        } else {
                            return res; //will go to success callback
                        }
                    },

                    responseError: function (res) {
                                                //统一处理请求没发成功的错误
                        TASApp.ajaxErrorHandler();
                        return $q.reject(res);
                    }
                };
            });

Angular2.x的http拦截器处理：

export class AddHttpHeaderInterceptor implements HttpInterceptor {

    constructor(private formService: FormService, private formHelper: FormHelper, private message: NzMessageService, private lang: Lang) {
    }

    intercept(req: HttpRequest<any>, next: HttpHandler) {

        // set  X-Requested-With that serve need to for ajax
        let clonedReq = req.clone({headers: req.headers.set(‘X-Requested-With‘, ‘XMLHttpRequest‘)});
        if (this.formService.currentUser) {
            //options http can not add x-auth-token, use param
            //clonedReq = req.clone({headers: req.headers.set(‘x-auth-token‘, this.formService.currentUser[‘x-auth-token‘])});

            //global add param x-auth-token and
            clonedReq = req.clone({params: req.params.set(‘x-auth-token‘, this.formService.currentUser[‘x-auth-token‘]),
                headers: req.headers.set(‘X-Requested-With‘, ‘XMLHttpRequest‘)});
        }

        // ===========================================================
        // global handle error
        // ===========================================================
        return next.handle(clonedReq).pipe(
            catchError(this.formService.handleError),
            //handle success false
            filter(res => {
            if(res[‘statusText‘] && res[‘statusText‘] === ‘OK‘){
                if(res[‘body‘] && (res[‘body‘][‘success‘] == false || res[‘body‘][‘success‘]==‘relogin‘)){
                    if(res[‘body‘][‘success‘] == ‘relogin‘){
                        //handle relogin here, can add some message
                        (<any>window).location.href = this.formHelper.getBaseUrl()+‘login‘;
                        return false;
                    } else {
                        //if no info will have a code
                        this.message.error(res[‘body‘][‘info‘] || this.lang.lang["errorCode"][res[‘body‘][‘code‘]]);
                        console.log(res);
                        //if return false will not trigger subscribe function, if you need trigger return true
                        return true;

                        /*
                        this will fire subscribe error handle, that means if backend error will go to subscribe->error,
                        subscribe->next is only handle backend success, bug if services use like MyShares/getFormInfo that will have problem,
                        need add error handle for every http request and run handler function
                        this.http.get(url).subscribe(obj=>{handle when backend success},error=>{handle when backend error}
                        */
                        //throw new Error("error");
                    }
                }
            }
            return true;
        })
        );
    }
}

@NgModule({
    declarations: [

    ],
    imports: [

    ],
    providers: [
        {provide: HTTP_INTERCEPTORS, useClass: AddHttpHeaderInterceptor, deps: [FormService, FormHelper, NzMessageService, Lang], multi: true},
        {provide: APP_INITIALIZER, useFactory: loginAndInitForm, deps: [FormService], multi: true},
        {provide: NZ_I18N, useValue: zh_CN},
        {provide: NZ_MODAL_CONFIG, useValue: {autoBodyPadding: true}},
        {provide: NZ_MESSAGE_CONFIG, useValue: {nzDuration: 3000}}
    ],
    bootstrap: [AppComponent]
})

原文地址：https://blog.51cto.com/13934921/2467421