Cannot use results of an api call in conversation - actions-on-google

Question

I am trying to use the results of an api call in conversation but haven't been able to pass the results so that I can use them in conv.ask. In the example here, I am able to log the "wind inner" but when I try to use it in conv.ask, I get "undefined." I know it is a scoping issue, but I haven't been able to solve it. Thanks!
app.intent('weather', (conv) => {
var url = "http://api.wunderground.com/api/"+apiKey+"/yesterday/q/55417.json";
var request = http.get(url, function (response) {
var buffer = "",
data,
history;
response.on("data", function (chunk) {
buffer += chunk;
});
response.on("end", function (err) {
console.log(buffer);
console.log("\n");
data = JSON.parse(buffer);
history = data.history;
var wind = (history.dailysummary[0].maxwspdi);
console.log("wind inner: ", wind);//this works
});
});
conv.ask("the wind speed is" + wind + "miles per hour");
//unable to get the wind variable to be defined ouside the api call
});

Answer 1

You should be using a Promise to return asynchronous responses. Additionally, make sure you wait until you get the response data to generate your text-to-speech. Here's a snippet that should work.
app.intent('weather', (conv) => {
return new Promise((resolve, reject) => {
const url = "http://api.wunderground.com/api/"+apiKey+"/yesterday/q/55417.json";
const request = http.get(url, function (response) {
var buffer = "",
data,
history;
response.on("data", function (chunk) {
buffer += chunk;
});
response.on("end", function (err) {
console.log(buffer);
console.log("\n");
data = JSON.parse(buffer);
history = data.history;
const wind = (history.dailysummary[0].maxwspdi);
console.log("wind inner: ", wind);//this works
conv.ask("the wind speed is" + wind + "miles per hour");
resolve();
});
});
});
});