How to update variable with nested functions?

Question

Here is a sample code

function() {
    var test = 0;
    var url = 'http://test.php';
    var user_id = 1;
    $http.post(url,{user_id: user_id})
    .then(function (response){ 
         test = response.something;
    })
    console.log(test)
}

It returns the value 0. I need it to return response.something.

You have to wait the promise to be resolved. See a similar situation here: http://stackoverflow.com/questions/43259349/how-to-access-a-returned-result-outside-the-then-in-javascript-angularjs/ — lealceldeiro, Apr 06 '17 at 16:09

peteb · Answer 1 · 2017-04-06T16:09:43.210

2

You're not invoking the function calling test = 1

You can wrap the inner function within an IIFE

function() {
    var test = 0;
    (function(){
        test = 1;
    })() // Call the expression immediately
    console.log(test)
}

Edit for Question Update

The console.log(test) is happening before the promise from $http.post() resolves, you need to move the console.log() within your then() callback.

function() {
    var test = 0;
    var url = 'http://test.php';
    var user_id = 1;
    $http.post(url,{user_id: user_id})
    .then(function (response){ 
         test = response.something;
         console.log(test) // Move console.log inside promise then
    })

}

edited Apr 06 '17 at 16:09

answered Apr 06 '17 at 15:58

peteb

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this does not work for me. i am updating my test inside this `$http.post(url,{user_id: loggedin_id}) .then(function (response){ this.test = 2; })` – Chowder Apr 06 '17 at 16:05
i have edited the sample code for better understanding. – Chowder Apr 06 '17 at 16:08
1

That totally changes the question because you're trying to log before the promise has returned – peteb Apr 06 '17 at 16:09
@TheChosenOne see updated answer – peteb Apr 06 '17 at 16:10
but i need to access test outside of $http.post(). How do i do that? – Chowder Apr 06 '17 at 16:12
You could return it or take it as a parameter – peteb Apr 06 '17 at 16:14

score 0 · Answer 2 · answered Apr 06 '17 at 16:13

It's because $http.post is an asynchronous method call. By the time your code gets to the console.log call at runtime, the data from $http.post may not have returned yet, therefore it would log the old value and not the new one.

If you want to console.log the value after the post request has returned, you should move the console.log statement to the then block which will only run after the call has been returned.

function() {
    var test = 0;
    var url = 'http://test.php';
    var user_id = 1;
    $http.post(url,{user_id: user_id})
    .then(function (response){ 
         test = response.something;
         console.log(test) // Move console.log inside promise then
    })

}

If that does not work for you, it is because your call is likely failing for some reason or another. In this case, you can provide an additional function to handle the error.

function() {
    var test = 0;
    var url = 'http://test.php';
    var user_id = 1;
    $http.post(url,{user_id: user_id})
    .then(function (response){ 
         test = response.something;
         console.log(test) // Move console.log inside promise then
    }, function(err) {
       test = err;
       console.log(test)
    });
   }

How to update variable with nested functions?

2 Answers2

Edit for Question Update