我需要帮助向 nodejs express 服务器（Angular Universal）中的外部 API 发出 API 请求

Question

I have an Angular Universal app. I am trying to access an external API, but doing it directly through the HttpClient generates a Cors error. In development, I successfully used a proxy to make the call. I am trying to implement a proxy in production by creating a route on my express server that will swap in the appropriate external API route. I am having trouble seeing anything online that can help with this particular situation. I seem to have set up the route ok. I'm getting a 200 ok error but no data is being sent. Can anyone help?

server.ts

app.route('/api/book').get((req, res) => {

  https.get('https://api2.isbndb.com/book/' + req, (resp) => {
    let data = '';

    // A chunk of data has been recieved.
    resp.on('data', (chunk) => {
      data += chunk;
    });

    // The whole response has been received. Print out the result.
    resp.on('end', () => {
      res.send(res.json(data)
      );
    });

  }).on("error", (err) => {
    console.log("Error: " + err.message);
  });


});

Answer 1

You can simply enable cors from your server side like this.

var express = require('express')
var cors = require('cors')
var app = express()

app.use(cors())

For better understanding or to configure cors() url through. can see here .

As by default it will call the options method to check the permission for the user to access that end points.

or you can use below example from client side api call,

let data = { name: 'Peter Parker', age: 34 };
 const results = await fetch(
  'http://localhost:3000/api/v1/results',
  {
    method: "post", 
    mode: "cors",
    headers: {
      "Content-Type": "application/json",
      "Access-Control-Allow-Origin": "*"
    },
    body: JSON.stringify(data)
  }
)
  .then(res => res.json()) 
  .then(res => {
    return res;
  })
  .catch(error => {
    error.response = {
      status: 0,
      statusText:
        "Cannot connect. Please make sure you are connected to internet."
    };
    throw error;
  });