Im trying to make a weather app and I'm using a weather API to get the information but this error shows up when I'm trying to parse the JSON data:
SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>) at IncomingMessage.<anonymous>
edit: I need to get the lat and lon values from an https request. I tried returning it but it will still say lon and lat is undefined.
second edit: If I input the values of lon and lat It will parse the data and send back the JSON but I need the values of lon and lat from the locaionIQ API on the https request. How do I get those values? here is the code:
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const https = require('https');
const { static, response } = require('express');
require('dotenv').config();
app.use(bodyParser.urlencoded({extended:true}));
app.use(express.static('public'))
app.listen(3000, ()=>{
console.log("server is running on port 3000")
})
app.get('/', (req,res)=>{
res.sendFile(__dirname+'/index.html')
})
app.post('/', (req,res)=>{
let apiKeyLocationIQ = process.env.API_KEY_LOCATIONIQ;
let apiKeyWeather = process.env.API_KEY_WEATHER;
let cityLocationIQ = req.body.citySearch;
let urlLocationIQ = "https://api.locationiq.com/v1/search.php?format=JSON&key="+apiKeyLocationIQ+"&q="+cityLocationIQ+"&limit=1";
https.get(urlLocationIQ, function(response){
response.on("data",function(data){
let locationIQ = JSON.parse(data);
const lat= locationIQ[0].lat;
const lon= locationIQ[0].lon;
const cityName = locationIQ[0].display_name;
})
})
let urlWeather = 'https://api.openweathermap.org/data/2.5/onecall?&lat='+lat+'&lon='+lon+'&exclude=alerts,minutely&units=metric&appid='+apiKeyWeather+'&lang=en&cnt=7';
https.get(urlWeather, function(response){
response.on("data",function(data){
let weatherData = JSON.parse(data);
console.log(weatherData);
})
})
})
Under Node, HTTP/HTTPS request data can arrive in multiple chunks which need to be amalgamated before parsing the resultant JSON string.
Essentially JSON parsing needs to be performed in an on("end", callback), not in an on("data", callback), or risk incomplete JSON text.
Node documentation has an excellent working example for getting JSON data under http.get(options[, callback]). This does not appear to be duplicated in the HTTPS section of documentation due to similarities of the HTTP and HTTPS APIs.
Https response data are collected in small chunks, so when its collecting data ("on"), we should append the data(string) in variable (starting with empty string [here let chunks="";])
When all the chunks of data are collected ("end"), then we should finally parse the string(API data) into JSON format.
https.get(apiLink, function (response) {
let chunks="";
response.on("data", function (chunk) {
chunks+=chunk;
});
response.on("end", function(){
// console.log("API Data recieved");
let defaultCovidData = JSON.parse(chunks);
// code after parse string into JSON format
});
});