Returning a value from a Promise

Question

I would like to call the Google Maps Geocoding API using a Promise like this:

function makeGeoCodingRequest(address,bounds)
{
    /*
        Input parameters         


        

Answer 1

If you depend on a promise in order to return your data, you must return a promise from your function.

Once 1 function in your callstack is async, all functions that want to call it have to be async as well if you want to continue linear execution. ( async = return a promise )

Notice that your if statement does not have braces and thus only the first statement after it will not be executed if the condition fails.

I fixed it in this example. Notice the remarks I added.

if(address){
    promise=Q($.ajax({
        type: "GET",
        url: "https://maps.googleapis.com/maps/api/geocode/json?address=" + address + "&key=API_KEY"
    }));
    return promise.then(function(data) {
        // whatever you return here will also become the resolve value of the promise returned by makeGeoCodingRequest
        // If you don't want to validate the data, you can in fact just return the promise variable directly
        // you probably want to return a rejected promise here if status is not what you expected
        if (data.status === "OK") return data;
            else console.error(messages[data.status]);
        return null;    
    });
}

You must call makeGeoCodingRequest in the following fashion.

makeGeoCodingRequest(address,bounds).then(function(data){
    // this will contain whatever 
    console.log(data);
});