javascript: getting the value of variables inside a callback function

Question

Im using google geocoder and I cant seem to find a way to set the value of the global variable inside the callback function

var status_temp;
var lat_temp;
var lng_temp;
var error_temp;
function set_status(status_input){
    status_temp=status_input;
}
function set_lat(lat_input){
    lat_temp=lat_input;
}
function set_lng(lng_input){
    lng_temp=lng_input;
}
function set_error(error_input){
    error_temp=error_input;
}
function geocode_address(address_input){
    var status_string;
    var error_message;
    var lat;
    var lng;
    geocoder.geocode( { 'address': address_input}, function(results, status){
        if (status == google.maps.GeocoderStatus.OK) {
            set_status('found');
            set_lat(results[0].geometry.location.lat());
            set_lng(results[0].geometry.location.lng());
        } else {
            console.log("Geocode was not successful for the following reason: " + status);
            set_status('notfound');
            set_status(status);
        }
    });
    console.log(status_temp);
    if(status_temp==='found'){
        var data = ({
            status_string:status_temp,
            lat:lat_temp,
            lng:lng_temp,
        });
    }else{
        var data = ({
            status_string:status_temp,
            error_string:error_temp,
        });
    }
    return data;
}

I tried doing the normal way to set global variables which is declaring the variable outside the function, this latest one ive tried is using functions to set variables. what am i doing wrong?

I'd suggest you read this to learn about dealing with return values from async calls. This post is about ajax calls, but it's the exact same issue as you have here: http://stackoverflow.com/questions/14220321/how-to-return-the-response-from-an-ajax-call — jfriend00, Oct 13 '14 at 02:31
all you need to do is move the console call into the callback. bam, done. — dandavis, Oct 13 '14 at 02:32
@dandavis - obviously, there's more of an objective here than just doing a `console.log()`. The OP has to learn how to handle async results either in the callback or by calling another function from the callback and passing the data to it. — jfriend00, Oct 13 '14 at 02:40
doing anything else to the data is just as simple as logging it. by producing something working, you realize (hopefully), "hey, i can just copy and paste the bottom half of my sync function into this callback!"... — dandavis, Oct 13 '14 at 02:41

score 2 · Answer 1 · answered Oct 13 '14 at 02:29

You need to read about asynchronous javascript calls.
You are attempting to use the globals when they havent been set yet.
Your function cannot just return, it needs to use a callback to return the values, and the callback needs to be called from inside the geocode callback
note that your question title says "inside a callback" but you are not doing the console log from inside, its currently from outside.

javascript: getting the value of variables inside a callback function

1 Answers1