Having trouble with Adding Success and Failure pages

Question

I am trying to create an app where I sign on clients to mailchimp and when I try to sign them up I get this error message:

ReferenceError: response is not defined
    at C:\Users\Owner\Desktop\Newsletter-Signup\app.js:57:3
    at Layer.handle [as handle_request] (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\layer.js:95:5)
    at next (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\route.js:144:13)
    at Route.dispatch (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\route.js:114:3)
    at Layer.handle [as handle_request] (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\layer.js:95:5)
    at C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\index.js:284:15
    at Function.process_params (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\index.js:346:12)
    at next (C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\express\lib\router\index.js:280:10)
    at C:\Users\Owner\Desktop\Newsletter-Signup\node_modules\body-parser\lib\read.js:137:5
    at AsyncResource.runInAsyncScope (async_hooks.js:193:9)

Here is my code at app.js

//require installed node packages
const express = require("express");
const https = require("https");

 
//create new express app
const app = express();
 
//enable express to access static files in the folder called "Public"
app.use(express.static("Public"));
 
//enable express to parse URL-encoded bodies
app.use(express.urlencoded({
  extended: true
}));
 
//send html file to browser on request
app.get("/", function(req, res) {
  res.sendFile(__dirname + "/signup.html");
});

 
//require mailchimp 
const client = require("@mailchimp/mailchimp_marketing"); //note that "mailchimp-marketing" causes errors

client.setConfig({
  apiKey: "f628d1e9327aaf60e1c9873ff13787f2-us21",
  server: "us21",
});
 
app.post("/", function(req, res) {
  //set up constants linked to html form input 'name' attributes
  const firstName = req.body.fName;
  const lastName = req.body.lName;
  const email = req.body.email;
 
//code from Node snippet linked above, but with members values filled in as described in Angela's video
  const run = async () => {
    const response = await client.lists.batchListMembers("347eed265e", {     

      members: [{
        email_address: email,
        status: "subscribed",
        merge_fields: {
          FNAME: firstName,
          LNAME: lastName
        }
      }],   

    });
 
    console.log(response);
  };
  if (response.statusCode === 200){
    res.send("Successfully subscribed!");
  } else {
     res.send("There was an error with signing up, please try again!");
  }
  run();
 
});
 
//use express app to listen on 3000 and log when it's working
app.listen(3000, function() {
  console.log("Server is running on port 3000.")
});

// API KEY
// f628d1e9327aaf60e1c9873ff13787f2-us21

// List ID
// 347eed265e

I was wondering if you can help me figure out any errors in my code Thanks, Mark

I tried to be able to sign up a client by putting the persons name and address in the field and hoping to get the response "Succussfully subscribed", instead of getting the error that I received.

Here is what my signup page looks like, when I try to sign up a client:

[Here is my form page for my app(https://i.stack.imgur.com/ok5iE.png)

Answer 1

response is only accessible within the function scope of run() . You have an if statement that references response outside of the scope where it is defined:

const run = async () => {
  const response = await client.lists.batchListMembers('347eed265e', {
    // <----------------- response scope start

    members: [
      {
        email_address: email,
        status: 'subscribed',
        merge_fields: {
          FNAME: firstName,
          LNAME: lastName,
        },
      },
    ],
  });

  console.log(response);
  // <----------------- response scope end
};

if (response.statusCode === 200) {
  res.send('Successfully subscribed!');
} else {
  res.send('There was an error with signing up, please try again!');
}
run();

Hope this helps.

Answer 2

As damonholden said your response is out scope inside the run() function, also I don't quite understand why you would wrap your code in the run function.

You should use the promise as it is:

app.post("/", function(req, res) {
    //set up constants linked to html form input 'name' attributes
    const firstName = req.body.fName;
    const lastName = req.body.lName;
    const email = req.body.email;
    client.lists.batchListMembers('347eed265e', 
    {
    members: [
      {
        email_address: email,
        status: 'subscribed',
        merge_fields: {
            FNAME: firstName,
            LNAME: lastName,
        },
      },
    ],
    }).then(response => {
        console.log(response);
        if (response.statusCode === 200) {
            res.send('Successfully subscribed!');
        } else {
            res.send('There was an error with signing up, please try again!');
        }
    }).catch(() => {
        res.send('There was an error with signing up, please try again!');
    });
});