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My weather app is throwing type error of temp.. It was console logging the data when I checked but as I enter city Lat and Log it shows type error [duplicate]

I'm trying to get my function to return the http get request, however, whatever I do it seems to get lost in the ?scope?. I'm quit new to Node.js so any help would be appreciated
function getData(){
var http = require('http');
var str = '';
var options = {
host: 'www.random.org',
path: '/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
};
callback = function(response) {
response.on('data', function (chunk) {
str += chunk;
});
response.on('end', function () {
console.log(str);
});
//return str;
}
var req = http.request(options, callback).end();
// These just return undefined and empty
console.log(req.data);
console.log(str);
}

Of course your logs return undefined : you log before the request is done. The problem isn't scope but asynchronicity.
http.request is asynchronous, that's why it takes a callback as parameter. Do what you have to do in the callback (the one you pass to response.end):
callback = function(response) {
response.on('data', function (chunk) {
str += chunk;
});
response.on('end', function () {
console.log(req.data);
console.log(str);
// your code here if you want to use the results !
});
}
var req = http.request(options, callback).end();

Simple Working Example of Http request using node.
const http = require('https')
httprequest().then((data) => {
const response = {
statusCode: 200,
body: JSON.stringify(data),
};
return response;
});
function httprequest() {
return new Promise((resolve, reject) => {
const options = {
host: 'jsonplaceholder.typicode.com',
path: '/todos',
port: 443,
method: 'GET'
};
const req = http.request(options, (res) => {
if (res.statusCode < 200 || res.statusCode >= 300) {
return reject(new Error('statusCode=' + res.statusCode));
}
var body = [];
res.on('data', function(chunk) {
body.push(chunk);
});
res.on('end', function() {
try {
body = JSON.parse(Buffer.concat(body).toString());
} catch(e) {
reject(e);
}
resolve(body);
});
});
req.on('error', (e) => {
reject(e.message);
});
// send the request
req.end();
});
}

Shorter example using http.get:
require('http').get('http://httpbin.org/ip', (res) => {
res.setEncoding('utf8');
res.on('data', function (body) {
console.log(body);
});
});

from learnyounode:
var http = require('http')
http.get(options, function (response) {
response.setEncoding('utf8')
response.on('data', console.log)
response.on('error', console.error)
})
'options' is the host/path variable

from learnyounode:
var http = require('http')
var bl = require('bl')
http.get(process.argv[2], function (response) {
response.pipe(bl(function (err, data) {
if (err)
return console.error(err)
data = data.toString()
console.log(data)
}))
})

I think it's too late to answer this question but I faced the same problem recently my use case was to call the paginated JSON API and get all the data from each pagination and append it to a single array.
const https = require('https');
const apiUrl = "https://example.com/api/movies/search/?Title=";
let finaldata = [];
let someCallBack = function(data){
finaldata.push(...data);
console.log(finaldata);
};
const getData = function (substr, pageNo=1, someCallBack) {
let actualUrl = apiUrl + `${substr}&page=${pageNo}`;
let mydata = []
https.get(actualUrl, (resp) => {
let data = '';
resp.on('data', (chunk) => {
data += chunk;
});
resp.on('end', async () => {
if (JSON.parse(data).total_pages!==null){
pageNo+=1;
somCallBack(JSON.parse(data).data);
await getData(substr, pageNo, someCallBack);
}
});
}).on("error", (err) => {
console.log("Error: " + err.message);
});
}
getData("spiderman", pageNo=1, someCallBack);
Like #ackuser mentioned we can use other module but In my use case I had to use the node https. Hoping this will help others.

This is my solution, although for sure you can use a lot of modules that give you the object as a promise or similar. Anyway, you were missing another callback
function getData(callbackData){
var http = require('http');
var str = '';
var options = {
host: 'www.random.org',
path: '/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
};
callback = function(response) {
response.on('data', function (chunk) {
str += chunk;
});
response.on('end', function () {
console.log(str);
callbackData(str);
});
//return str;
}
var req = http.request(options, callback).end();
// These just return undefined and empty
console.log(req.data);
console.log(str);
}
somewhere else
getData(function(data){
// YOUR CODE HERE!!!
})

Make HTTP get request

I am trying to make a HTTP get request, but nothing is being returned as text. Here is my code
const http = require('http');
const ws = require('ws');
const wss = new ws.Server({noServer: true});
var XMLHttpRequest = require('xhr2');
function accept(req, res) {
console.log("got request")
wss.handleUpgrade(req, req.socket, Buffer.alloc(0), function(ws) {
//party name, sockets on party, limit 2
ws.on('message', function (msg) {
var message = JSON.parse(msg.toString())
if(message.type==='add') {
//do later
} else if(message.type==='start') {
httpGetAsync('192.168.26.23', "/startRelay")
} else if(message.type==='stop') {
httpGetAsync('92.168.26.23', "/stopRelay")
} else if(message.type==='status') {
httpGetAsync('92.168.26.23', "/")
}
});
ws.on('close', function () {
console.log('closed')
});
ws.on('error', function(error){
console.log('error - ' + JSON.stringify(error));
});
})
}
function httpGetAsync(theUrl, path) {
var options = {
host: theUrl,
path: path,
method: "GET",
}
callback = async function(response) {
var str = ''
response.on('data', function (chunk) {
str += chunk;
});
response.on('end', function () {
console.log(JSON.parse(str));
});
};
http.request(options, callback).end();
}
http.createServer(accept).listen(3000);
Here is what 192.168.26.23 has in it (if you type it up from my wifi onto google, this is what shows - and this data is what I need to get in a string)
{"success":true,"ms_left":0,"relayStarted":false}

node can't set headers after they are sent

i know this question asked many time before but still i'm struggling to figure this out. i have a set of js files. first one is index.js
app.all('/backend/*/*', function(req, res){ // backend/product/getProduct
serviceType = req.params[0];
methodType = req.params[1];
exports.serviceType= serviceType;
exports.methodType= methodType;
main.checkService()
});
in here im extracting the params and call checkService method in main.js file
main.js
function checkService(){
switch(index.serviceType){
case 'product':
product.checkMethod();
break;
default :
console.log('no such service')
}
}
then it move to product.js file
function checkMethod(){
var methodName = index.methodType,
res = index.res,
req = index.req;
switch(methodName){
case 'samplePost':
var body = req.body;
proHan.samplePost(body,function(data,msg,status){
sendRes(data,msg,status);
});
break;
default :
console.log('no such method')
}
function sendRes(jsonObj,msg,status){
var resObj = {
status : status,
result : jsonObj,
message : msg
}
res.json(resObj);
}
first it moves to samplePost method in handler.js
once the http req finised executing, callback return the results and call sendRes method and send the json
function samplePost(jsonString,cb){
var res = config.setClient('nodeSample');
// jsonString = JSON.parse(jsonString);
res.byKeyField('name').sendPost(jsonString,function(data,msg,status){
cb(data,msg,status);
});
}
to send http req i written a common file. that is config.js
function setClient(_cls){
var client = new Client(url);
return client;
}
function parentClient(url){
this.postBody = {
"Object":{},
"Parameters":{
"KeyProperty":""
}
};
}
function paramChild(){
parentClient.apply( this, arguments );
this.byKeyField = function(_key){
this.postBody.Parameters.KeyProperty = _key;
return this;
}
}
function Client(url){
parentClient.apply( this, arguments );
this.sendPost = function(_body,cb){
_body = (_body) || {};
this.postBody.Object = _body;
var options = {
host : 'www.sample.com',
port : 3300,
path: '/somrthing',
headers: {
'securityToken' : '123'
}
};
options.method = "POST";
var req = http.request(options, function(response){
var str = ''
response.on('data', function (chunk) {
str += chunk;
});
response.on('end', function () {
cb(JSON.parse('[]'),'success',200)
});
});
//This is the data we are posting, it needs to be a string or a buffer
req.on('error', function(response) {
cb(JSON.parse('[]'),response.errno,response.code)
});
req.write(JSON.stringify(this.postBody));
req.end();
}
}
paramChild.prototype = new parentClient();
Client.prototype = new paramChild();
when i send the first req its work but from then again the server crashes. it seems like i can't call res.end method again in a callback method. how can i fix this. thank you.

you can't call res.end two times. Here is a simple exemple to deal with callback with a basic node server.
const http = require('http');
const hostname = '127.0.0.1';
const port = 4242;
let something = true;
function callback(req, res) {
something = !something;
res.setHeader('Content-Type', 'text/plain');
res.end('Callback Hello World\n');
}
const server = http.createServer((req, res) => {
res.statusCode = 200;
if (something) {
callback(req, res);
} else {
something = !something;
res.setHeader('Content-Type', 'text/plain');
res.end('Hello World\n');
}
});
server.listen(port, hostname, () => {
console.log(`Server running at http://${hostname}:${port}/`);
});

How to run a http.request inside a imported module. Its not running when I am trying to access

My main.js file:
var spaceJson = require('./space.js');
var options = {
"method": "GET",
"hostname": "10.10.111.226",
"port": null,
"path": "/API/Org",
"headers": {
"authorization": "Bearer eyJ0eXAiOiJKV1QiLCJhbG...",
"cache-control": "no-cache"
}
};
var JSONdata = spaceJson.space.getSpaceData(options);
my space.js file(this actually is making a request to a web api and returns json)
var module = module.exports = {};
var http = require("http");
module.space = {
sayHelloInSpanish: function() {
return "Hola";
},
getSpaceData : function(options) {
var body = '';
http.request(options, function (req,res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
body = Buffer.concat(chunks);
console.log(body.toString());
});
req.end();
});
//return http.get();
}
};
var require = function(path){
return module.exports;
};
when I call
sayHelloInSpanish
method, it returns "holla" when I run main.js. But when I call the
getSpaceData
I dont see anything on command line and it hangs. Maybe I am not handling callback. With this I basically want to consume JSON data in my main.js

You don't see anything because The HTTP response is async.
You should return a callback or use a promise:
getSpaceData : function(options, clbk) {
var body = '';
http.request(options, function (req,res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
body = Buffer.concat(chunks);
console.log(body.toString());
clbk(body.toString());
});
req.end();
});
}
spaceJson.space.getSpaceData(options, function(data){
console.log(data);
});
I recommend you to watch this video: https://vimeo.com/96425312
-- UPDATE --
Delete the require code:
var require = function(path){
return module.exports;
};
add to main:
// main.js
var spaceJson = require("./space.js");

Async with http Node.js

I have 2 asynchronous functions on gives me some urls and other one gives me the content I need from the url and one that writes the content I need to an file, but it write to file first and then it gives me the content I need to write, how can I get him to write to file after I get the content I need. Thanks
var http = require('http');
var fs = require('fs');
var list = {};
var k = 0;
function getContent(url){
var options = {
host: 'www.exammple.org',
path: url
}
var request = http.request(options, function (res) {
var data = '';
res.on('data', function (chunk) {
data += chunk;
});
res.on('end', function () {
list[k] = data;
k++;
});
});
request.on('error', function (e) {
console.log(e.message);
});
request.end();
}
var options = {
host: 'www.example2.org',
path: '/mypath'
}
var request = http.request(options, function (res) {
var data = '';
res.on('data', function (chunk) {
data += chunk;
});
res.on('end', function () {
///Here I get some urls from data
data = data.split(";");
for(key in data){
data = data.split('href=\"')[1].split('"')[0];
getContent(data[key]);
}
writeToFile();
}
});
});
request.on('error', function (e) {
console.log(e.message);
});
function writeToFile(){
fs.writeFile("file.txt", JSON.stringify(list), function(err) {
if(err) {
console.log(err);
} else {
console.log("The file was saved");
}
});
}
request.end();