Can't update javaScript global variable

Question

Here I have global variable userId, and i want to update it inside signInUserFunction(), to use is in other function. I have tried to define it using var, window, But all these didn't help. This variable doesn't update. As i see its about AJAX async. So, what can i do with it?

And yes, I know that its not good to make authentication with JS, I am quite new to it. So, I am just creating random methods to improve.

var userId = 1;

function signInUser() {
  $.getJSON('http://localhost:8887/JAXRSService/webresources/generic/getAllUsers', function(data) {
  var items = [];
  var i = 0;
  $.each(data, function(firstname, value) {

    var str = JSON.stringify(value);
    data = JSON.parse(str);
    var innerId;
    for (p in data) {
      innerId = data[p].id;
      if ($('#nameSignIn').val() == data[p].first_name && $('#passwordSignIn').val() == data[p].password) { //
        userId = innerId;
        window.location.href = "content.html";
        break;
      } else {
        i++;
        if (i == data.length) {
          alert("Ощибка в логине или пароле!")
        }
       }
      }

    });
  });
}

Answer 1

How are you determining whether or not it has been set? It looks like immediately after you set it, you navigate to a different page. When you get to that page, you will have an entirely new window.

Try alerting the value before navigating away.

EDITED: Here is how you could pass it to the other page (but you shouldn't do this in a real app)

        window.userId=innerId;
        alert(window.userId);

        //this isn't a very secure way to do this. I DON'T recommend this
        window.location.href = "content.html?id=" + innerId ;

Then in the other page, you could access it off the document.location:

alert(document.location.toString().split("?id=")[1]);

Answer 2

Using the idea @mcgraphix proposed (and giving you the same warning...this would certainly not be the way to transfer data like this in a production environment), here is one way to do it:

function signInUser() {
  var url = 'http://localhost:8887/JAXRSService/webresources/generic/getAllUsers';
  var userId;

  $.getJSON(url, function(data) {
    $.each(data.Actors, function(index, actor) {
      // Cache the values of the #nameSignIn and #passwordSignIn elements
      var name = $('#nameSignIn').val();
      var password = $('#passwordSignIn').val();

      if (actor.first_name === name && actor.password === password) {
        // We have found the correct actor.
        // Extract its ID and assign it to userId.
        userId = actor.id;
        window.location.href = "content.html?userId=" + userId;
      }
    });

    // This alert should only be reached if none of the actor objects
    // has a name and password that matches your input box values.
    alert("Ощибка в логине или пароле!"); 
  });
}

// On the next page...
// Top answer from http://stackoverflow.com/questions/2090551/parse-query-string-in-javascript
// This approach can handle URLs with more than one query parameter,
// which you may potentially add in the future.
function getQueryVariable(variable) {
  var query = window.location.search.substring(1);
  var vars = query.split('&');

  for (var i = 0; i < vars.length; i++) {
    var pair = vars[i].split('=');

    if (decodeURIComponent(pair[0]) == variable) {
      return decodeURIComponent(pair[1]);
    }
  }

  console.log('Query variable %s not found', variable);
}

var userId = getQueryVariable('userId');

Answer 3

After reading my comments, you may want to try this:

var userId = 1; 
function signInUser(){
  $.getJSON('http://localhost:8887/JAXRSService/webresources/generic/getAllUsers', function(data){
    var items = [], actors = data.Actors, l = 0;
    $.each(actors, function(i, o){
      l++;
      if($('#nameSignIn').val() === o.first_name && $('#passwordSignIn').val() === o.password){
        userId = o.id;
        // this will redirect before any other code runs -> location = 'content.html';
        if(l === actors.length){
          alert('End of Loop');
        }
      }
    });
  });
}
signInUser();

I would not store sensitive data in JSON such as passwords. Use a database. There is no need to get all the data at the same time either.

Answer 4

Thanks you for help.Ended it all with usage of:

sessionStorage.getItem('label')
sessionStorage.setItem('label', 'value')