API Request in Dialogflow Fulfillment (Javascript) - api

Question

So I'm trying to make a google action using Dialogflow that requires an external API. I've always used jQuery .getJSON() to make API calls, so I had no idea how to do this. After searching this up online, I found a way to do this using vanilla javascript (I also tested the way on my website and it worked fine). The code for that is below:
function loadXMLDoc() {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == XMLHttpRequest.DONE) {
console.log(xmlhttp.responseText);
}
};
xmlhttp.open("GET", "https://translate.yandex.net/api/v1.5/tr.json/translate?lang=en-es&key=trnsl.1.1.20190105T052356Z.7f8f950adbfaa46e.9bb53211cb35a84da9ce6ef4b30649c6119514a4&text=eat", true);
xmlhttp.send();
}
The code worked fine on my website, but as soon as I added it to the Dialogflow, it would give me the error
XMLHttpRequest is not defined
Obviously that happened because I never defined it (using var), except it worked without me doing anything. So then, I tried adding this line
var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
to the code, and it stopped giving me the error (because I defined XMLHttpRequest). But then, my code wouldn't work.
TL;DR: How can I make an external API call using Dialogflow fulfillment?

Answer 1

You can use https. But make sure that you upgrade to Blaze Pay(or any other plans) to make external API calls, else you will receive an error such as
Error:
Billing account not configured. External network is not accessible and quotas are severely limited. Configure billing account to remove these restrictions.
Code to make external api call,
// See https://github.com/dialogflow/dialogflow-fulfillment-nodejs
// for Dialogflow fulfillment library docs, samples, and to report issues
"use strict";
const functions = require("firebase-functions");
const { WebhookClient } = require("dialogflow-fulfillment");
const { Card, Suggestion } = require("dialogflow-fulfillment");
const https = require("https");
process.env.DEBUG = "dialogflow:debug"; // enables lib debugging statements
exports.dialogflowFirebaseFulfillment = functions.https.onRequest(
(request, response) => {
const agent = new WebhookClient({ request, response });
console.log(
"Dialogflow Request headers: " + JSON.stringify(request.headers)
);
console.log("Dialogflow Request body: " + JSON.stringify(request.body));
function getWeather() {
return weatherAPI()
.then(chat => {
agent.add(chat);
})
.catch(() => {
agent.add(`I'm sorry.`);
});
}
function weatherAPI() {
const url =
"https://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=b6907d289e10d714a6e88b30761fae22";
return new Promise((resolve, reject) => {
https.get(url, function(resp) {
var json = "";
resp.on("data", function(chunk) {
console.log("received JSON response: " + chunk);
json += chunk;
});
resp.on("end", function() {
let jsonData = JSON.parse(json);
let chat = "The weather is " + jsonData.weather[0].description;
resolve(chat);
});
});
});
}
function welcome(agent) {
agent.add(`Welcome to my agent!`);
}
function fallback(agent) {
agent.add(`I didn't understand`);
agent.add(`I'm sorry, can you try again?`);
}
let intentMap = new Map();
intentMap.set("Default Welcome Intent", welcome);
intentMap.set("Default Fallback Intent", fallback);
intentMap.set("Weather Intent", getWeather);
agent.handleRequest(intentMap);
}
);

Answer 2

This article is a diamond! It really helped to clarify what's going on and what's required in Dialogflow fullfilments.
A small suggestion is to gracefully catch the error in the connection to the webservice:
function weatherAPI() {
const url = "https://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=b6907d289e10d714a6e88b30761fae22";
return new Promise((resolve, reject) => {
https.get(url, function(resp) {
var json = "";
resp.on("data", function(chunk) {
console.log("received JSON response: " + chunk);
json += chunk;
});
resp.on("end", function() {
let jsonData = JSON.parse(json);
let chat = "The weather is " + jsonData.weather[0].description;
resolve(chat);
});
}).on("error", (err) => {
reject("Error: " + err.message);
});
});
}