How to make the execution of functions in turn?

Question

JavaScript

A bit of history about how the script works...
When I run the script, it happens that the status function is executed and the value is immediately returned undefined, after which this value is returned return status(); after page.open(url, status); loaded callback returns the value success, but this value does not get into return status(); it is still undefined there.
The question for such js connoisseurs is how to do what after loading the page using page.open(url, status); get the success or fail status and give it at the output of the xPage(' https://ya.ru/ ') function, boolean value True or False.

var webPage = require('webpage'),
    page = webPage.create();


function xPage(url){

  var xStatus = function(status, a) {
   
   if(status === 'success')
   {
   	console.log('StatusPage: ' + status);
    
    a = 'ggggggggggggg';
    return{a:a}
   }
   
   else
   
   if(status === 'fail')
   console.log('StatusPage: ' + status);

   else
   console.log('Status = undefined');
   
  }

  var b;
  page.open(url, xStatus(b));

  console.log(b);
  
}

xPage('https://ya.ru/');

Answer 1

How can I make a function run only after another one has completed?

Answer 2

Using classic promises , it would look something like this

var webPage = require('webpage'),
    page = webPage.create();

var Promise = require('bluebird');

function xPage(url){

    return new Promise(function (resolve, reject) {
       page.open(url, function (status) {
           if (status !== 'success') {
               console.log('StatusPage: ' + status);
               reject(status);
           } else {
               console.log('StatusPage: ' + status);
               var a = 'ggggggggggggg';
               resolve({
                   a: a
               });
           }
       });
   });
    
}

xPage('https://ya.ru/')
    .then(function (stat) {
        console.log( JSON.stringify(stat) );
        page.render(Date.now() + '.png');
        phantom.exit();
    })
    .catch(function(err){ console.log(err) })
;

bluebird is installed as usual by
being in the phantomjs project folder