How to make use of fetched data from mongodb in node.js

Question

I've been able to fetch the data from the database, but then i'm trying to make use of it but it's not working,

var a = function() {
  first
    .find(
      { url: "https://guarded-everglades-31972.herokuapp.com/getCalls" },
      { url: 1 }
    )
    .then(url => {
      if (!url) {
        return console.log("url not found");
      }
      console.log("Todo by id", url);
    })
    .catch(e => console.log(e));
};

var accountSid = "…";
var authToken = "…";

var client = require("twilio")(accountSid, authToken);

client.calls.create(
  {
    url: a(),
    to: "+2348033260017",
    from: "+1 714 361 9371"
  },
  function(err, call) {
    if (err) {
      console.log(err);
    } else {
      console.log(call.sid);
    }
  }
);

I'm trying to use the fetched url from the function as the url for the twilio app, but it's telling me that i need to provide a url.

Answer 1

You are looking up the URL in an asynchronous callback function:

url => {
  if (!url) {
    return console.log("url not found");
  }
    console.log("Todo by id", url);
}

Because of this, your call to a() doesn't return the url as you might expect:

client.calls.create(
{
  url: a(), <-- here is the problem
  to: "+2348033260017",
  from: "+1 714 361 9371"
},

Instead, you want to use the url inside the callback function. Something like this:

var accountSid = "…";
var authToken = "…";

var client = require("twilio")(accountSid, authToken);

var a = function() {
  first.find(
      { url: "https://guarded-everglades-31972.herokuapp.com/getCalls" },
      { url: 1 })
    .then(url => {
      if (url) {
        client.calls.create({
          url,
          to: "+2348033260017",
          from: "+1 714 361 9371"
        },
        function(err, call) {
          if (err) {
            console.log(err);
          } else {
            console.log(call.sid);
          }
        });
      }
    });
};