I am happened to start a projects' frontend with Next.js v13.4 app router, and i also have an additional backend. I use api folder under app directory to manage routes and all that stuff. When i try to login fetch() function throws error : net::ERR_BLOCKED_BY_CLIENT

我碰巧用Next.js v13.4应用路由器启动了一个项目的前端，我也有一个额外的后端。我使用app目录下的api文件夹来管理路线之类的东西。当我尝试登录时，Fetch()函数引发错误：NET：：ERR_BLOCKED_BY_CLIENT

Even though it was working on my local host, i tried to deploy it and after i deploy it on a remote ubuntu, fetch function doesn't work. The problem is not on backend or anything since when i curl it works and when i request w/ Postman it also works. I tried to open it on private tab (which closed every plugin) but it didn't work either, still only thing i see is error.

即使它在我的本地主机上工作，我试图部署它，在我将其部署到远程ubuntu上后，获取功能不起作用。这个问题不是后端或任何东西，因为当我卷曲它的工作，当我要求w/邮递员它也工作。我试图打开它的私人标签（关闭每个插件），但它也没有工作，仍然只有我看到的是错误。

'use client';
import {NextPage} from 'next';
import {Formik, Form} from 'formik';
import * as Yup from 'yup';
import CrButton from '@/components/CrButton';
import logger from '@/utils/logger';
import useTheme from '@/utils/hooks/useTheme';
import {useEffect, useState} from 'react';
import {useRouter} from 'next/navigation';
import {toast} from 'react-toastify';

interface Props {
  section: string;
}

interface Values {
  email: string;
  password: string;
}

async function register(values: Values, role: string) {
  const res = await fetch(
    `http://localhost:3000/api/add?email=${values.email}&password=${
      values.password
    }&role=${role.toUpperCase()}`,
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
    }
  );

  const json = await res.json();

  return json;
}

const SubRegisterPage: NextPage<Props> = ({section, ...rest}) => {
  //...code
  async function handleOnSubmit(values: Values) {
    const res = await register(values, role);
    if (res.data.code === 200) {
      router.push('/login');
      toast.success('Aramıza katıldın, giriş yapmayı unutma!');
    }
    if (res.data.code == 1004) {
      toast.error(res.data.message);
    }
  }
}

Uh, I solved the problem afterwards and after several errors (now all fixed :) ).

呃，我后来解决了这个问题，在几次错误之后(现在都修复了：))。

The problem was related to how the concepts of Server Side Components and Client Server Components work. In Client SC, the fetch is made by client (users' browsers) therefore it directs the request to their localhost while we expect it to work on server's localhost.

问题与服务器端组件和客户端服务器组件的概念如何工作有关。在客户端SC中，获取是由客户端(用户的浏览器)进行的，因此它将请求定向到他们的本地主机，而我们期望它在服务器的本地主机上工作。

For anyone who have this issue, you have two options:

对于任何有此问题的人，您有两个选择：

1. You can try to create a route.ts file for each fetch request you want to make in a path/folder (e.g app/api/auth/login), then in the client server component fetch the route.ts using the path. Since route.ts is a server component, its localhost will point to the remote's ,or server's, localhost; thus, you can make a backend / an api call from localhost (e.g localhost:3006/auth/login).

   
   



2. If you are now willing not to make first one (if you don't want to make fetch requests or if your request should be work on client as in my case to attach cookie to users's client [the cookie set to frontend from backend in server will attach the token to server's cookies, not the clients' cookies ]), then you should create another apache or nginx conf for backend and use it. However in case you want your frontend to have ssl certificate, browser will coerce you to make backend https as well. you can't use let's encrypt for backend since it only accepts one conf file (only 1 domain). Therefore i created a subdomain for my backend (api.domain.com) and then get certificate using acme.sh (let's encrypt using it so it shouldn't be problematic).