NodeJS… Saving JSON to a Variable

Question

I'm a bit of a newbie to NodeJS, but I've looked around all over and can't seem to find a solution to my problem below. I'm sure it's something simple, but thanks in advance for all help you can give me!

I'm trying to make a simple JSON scraper via NodeJS. All I need is for JSON to be stored to a variable. The problem is, I'm using Require, and their example just logs it to console. I've tried adding a variable after it's logging to the console, but I'm just getting undefined. Here's my code below, it's pretty simplistic so far :)

//  var jsonVariable; Doesn't work, shown as a test
function getJSON(url){
    var request = require("request")

    request({
    url: url,
    json: true
}, function (error, response, body) {

    if (!error && response.statusCode === 200) {
        console.log(body) // Print the json response
        //return body;  This doesn't work, nor does making a global variable called json and assigning it here. Any ideas?
        //jsonVariable = body; // This also doesn't work, returning undefined even after I've called the function with valid JSON
    }
})
}

Once again, thanks so much for any help you can give me :)

Answer 1

The problem is that the request method is asynchronous, but you're trying to synchronously return a result. You'll need to either make a synchronous request (which doesn't appear to be possible with the request package you're using), or else pass a callback function to be called when the request responds successfully. eg:

var request = require("request")

function getJSON(url, callback) {
  request({
    url: url,
    json: true
  }, function (error, response, body) {
    if (!error && response.statusCode === 200) {
      callback(body);
    }
  });
}

getJSON('http://example.com/foo.json', function (body) {
  console.log('we have the body!', body);
});

Answer 2

If you use 'return body' where does it return to? That function is being called as a parameter to the request() function. You also cannot define a variable in your anonymous function because you will not have access to it outside of that scope.

What you need to do is define a variable outside of function getJSON() and then save body to that.

eg,

var result;

function getJSON(url){
  var request = require("request")

  request({
    url: url,
    json: true
    }, function (error, response, body) {
      if (!error && response.statusCode === 200) {
        result = body; 
      }
  });
}