Develop Reference

Wait for the request to finish before returning

In the code below, I try to return arr with details in it, but I think it's empty, because of the request. What can I do to make this work?
module.exports = function getWeather(country) {
var arr = [];
var pageToVisit = "https://www.timeanddate.com/weather/" + country;
console.log("Visiting page " + pageToVisit);
request(pageToVisit, function(error, response, body) {
if (error) {
console.log("Error: " + error);
}
// Check status code (200 is HTTP OK)
console.log("Status code: " + response.statusCode);
if (response.statusCode === 200) {
// Parse the document body
var $ = cheerio.load(body);
console.log("Page title: " + $('title').text());
$('div.bk-focus__qlook').each(function(index) {
var title = $(this).find('div.h2').text().trim();
//var link = $(this).find('div.h1').attr('href');
console.log('title: ' + title);
//console.log(link);
arr.push(title)
});
}
});
return arr;
}
The arr is always empty, and I can't add the title to the arr. How can I wait for it?

I would write a function :
function pagetovisit( parameters if necessary) {
// logic whatever you want to do
}
async function asyncCall() {
/// stock the return value in a var
const result = await pagetovisit();
console.log(result);
// expected output: "resolved"
}

It does not look like that website uses a public-facing weather API. Looks like an pre-rendered HTML page that loads from the server.
The API information does even include weather: https://www.timeanddate.com/services/api/
If you were to return a list of scraped text, you would need to make your function a asynchronous and return the Promise like so:
const parseHTML = (htmlText) =>
new DOMParser().parseFromString(html, 'text/html');
const getWeather = async (country, city) {
var pageToVisit = `https://www.timeanddate.com/weather/${country}/${city}`
console.log(`Visiting page: ${pageToVisit}`);
return fetch(pageToVisit, {
method: 'GET',
headers: {
'Content-Type': 'text/html',
}
})
.then(response => response.text())
.then(parseHTML)
.then(doc =>
[...doc.querySelectorAll('div.bk-focus__qlook')].map(qlook =>
qlook.querySelector('div.h2').textContent.trim()));
};
module.exports = getWeather;
// https://www.timeanddate.com/weather/usa/chicago
const weather = await getWeather('usa', 'chicago'); // Should not be empty
I would ditch this website, because:
Scraping is inefficient
There are better (and free) weather APIs out there

thank you all, I use callback fun and it work.
var cheerio = require('cheerio');
var URL = require('url-parse');
var express = require('express');
var country="canada";
module.exports= function getWeather(country,callback){
var arr=[];
arr.push(country)
var pageToVisit = "https://www.timeanddate.com/weather/"+country;
console.log("Visiting page " + pageToVisit);
request(pageToVisit, function(error, response, body) {
if(error) {
callback(error);
}
// Check status code (200 is HTTP OK)
console.log("Status code: " + response.statusCode);
if(response.statusCode === 200) {
// Parse the document body
var $ = cheerio.load(body);
console.log("Page title: " + $('title').text());
$('div.bk-focus__qlook').each(function( index ) {
var temp = $(this).find('div.h2').text().trim();
var wind = $(this).find('p').text().trim();
var index=wind.search("Wind")
wind=wind.substring(index);
arr.push(temp)
arr.push(wind)
});
}
callback(null, arr);
});
}
getWeather(country, function(err, result){
if(err) {console.log(err); }
else {
console.log(result);
}
});

Formidable/NodeJS HTTP Server JPG save

Stackoverflow JS Genius's!
I have an issue with my current project, it's using node's HTTP createServer, using Formidable to parse the body data.
See code below. (http-listener.js)
var listenport = 7200;
const server = http.createServer((req, res) => {
// Set vars ready
var data = '';
var plateImg = '';
var overview1 = '';
var overview2 = '';
new formidable.IncomingForm().parse(req)
// I originally thought it was sent in files, but it isnt, it's fields.
.on('file', function(name, file) {
console.log('Got file:', name);
})
// This is the correct procedure for my issue.
.on('field', function(name, field) {
console.log('Got a field:', name);
if(name.toLowerCase() === "anpr.xml")
{
// DO PARSE INTO JSON! This works, all is well.
xml2js.parseString(field, {explicitArray:false, ignoreAttrs:true}, function (err, result)
{
if(err)
{
alert('Parse: '+err);
}
// Console log parsed json data.
console.log("Read: "+result.EventNotificationAlert.ANPR.licensePlate);
console.log(result);
data = result;
});
}
if(name.toLowerCase() === "licenseplatepicture.jpg")
{
plateImg = field
// This doesnt work?
// I need to store these fields as an image. ? Is this possible with it being sent as a field and not as a file upload.
// This is the only option I have as I can't control the client sending this data (It's a camera)
fs.writeFile(config.App.ImageDir+'/Plate.jpg', plateImg, function(err) {
if(err)console.log(err);
});
}
if(name.toLowerCase() === "detectionpicture.jpg")
{
if(overview1 == '')
{
overview1 = field;
}
else if(overview2 == '')
{
overview2 = field;
}
else
{
// do nothing else.
console.log("Couldn't send images to variable.");
}
}
})
.on('error', function(err) {
alert(err);
})
.on('end', function() {
// Once finished, send to ANPR data to function to handle data and insert to database. WORKS
// Call anpr function.
ANPR_ListenData(data, plateImg, overview1, overview2, function(result) {
if(result.Status > 0)
{
console.log("Accepted by: "+result.Example);
// reset var
data = '';
plateImg = '';
overview1 = '';
overview2 = '';
res.writeHead(200, {'content-type':'text/html'});
res.end();
}
});
});
});
server.listen(listenport, () => {
console.log('ANPR Server listening on port: ' + listenport);
});
Basically the images that are sent in the fields: licenseplatepicture.jpg etc I want to store them directly into my app image directory.
Unfortunately I have no control over how the chunks are sent to this server due to it being a network camera, I simply need to write a procedure.
The full request chunk is quite large so I will upload the file to OneDrive for you to glance at and understand the request.
Any help with this will be appreciated. I've tried everything I can possibly think of, but the file saves unreadable :(. I don't know where else to look or what else I can try, other than what I've already done & tried.
Request Txt File: https://1drv.ms/t/s!AqAIyFoqrBTO6hTwCimcHDHODqEi?e=pxJY00
Ryan.

I fixed this by using Busboy package instead of Formidable.
This is how my http listener looks like using Busboy.
var inspect = util.inspect;
var Busboy = require('busboy');
http.createServer(function(req, res) {
if (req.method === 'POST') {
//vars
var ref = Math.random().toString(36).substring(5) + Math.random().toString(36).substring(2, 15);;
var xml = '';
var parseXml = '';
var over1, over2 = '';
var i = 0;
var busboy = new Busboy({ headers: req.headers });
busboy.on('file', function(fieldname, file, filename, encoding, mimetype) {
console.log('File [' + fieldname + ']: filename: ' + filename + ', encoding: ' + encoding + ', mimetype: ' + mimetype);
if(filename.toLowerCase() === "licenseplatepicture.jpg")
{
var saveTo = config.App.ImageDir+"/"+ref+"_Plate.jpg";
if (!fs.existsSync(saveTo)) {
//file exists
file.pipe(fs.createWriteStream(saveTo));
}
}
if(filename.toLowerCase() === "detectionpicture.jpg")
{
i++;
var saveTo = config.App.ImageDir+"/"+ref+"_Front_"+i+".jpg";
if (!fs.existsSync(saveTo)) {
//file exists
file.pipe(fs.createWriteStream(saveTo));
}
}
file.on('data', function(data) {
if(filename.toLowerCase() === "anpr.xml")
{
xml += data;
}
console.log('File [' + fieldname + '] got ' + data.length + ' bytes');
});
file.on('end', function() {
console.log('File [' + fieldname + '] Finished');
});
});
busboy.on('field', function(fieldname, val, fieldnameTruncated, valTruncated, encoding, mimetype) {
console.log('Field [' + fieldname + ']: value: ' + inspect(val));
// No fields according to busboy
});
busboy.on('finish', function() {
// DO PARSE INTO JSON! This works, all is well.
xml2js.parseString(xml, {explicitArray:false, ignoreAttrs:true}, function (err, result)
{
if(err)
{
alert('Parse: '+err);
}
// Set parsed var
parseXml = result;
});
var images = '';
if(i = 2)
{
images = `{"Plate":"${ref}_Plate.jpg", "Front":"${ref}_Front_1.jpg", "Overview":"${ref}_Front_2.jpg"}`;
} else {
images = `{"Plate":"${ref}_Plate.jpg", "Front":"${ref}_Front_1.jpg", "Overview":"null"}`;
}
// Once parsed, send on to ANPR listen function.
ANPR_ListenData(ref, parseXml, images, function(result) {
if(result.Status == 1)
{
console.log('Data transfered for: '+parseXml.EventNotificationAlert.ANPR.licensePlate);
console.log('Accepted Camera: '+result.Example);
res.writeHead(200, { Connection: 'close', Location: '/' });
res.end();
}
});
});
req.pipe(busboy);
}
}).listen(7200, function() {
console.log('Listening for requests');
});
Hope this helps someone else in the future. Certainly caused me a lot of a wasted time.
Busboy was the better package to use when I was reading into it more, it makes more sense for what I was attempting to achieve.
Ryan :).
All the best.

Have set up mongodb, mongoose etc but when I try and add something to the database it doesn't actually add it

I'm using localhost and have all the modules set up correctly and I've checked that the database exists. When I type in localhost:3000/pods/add?firstName='John' it's supposed to add it to the database, but for some reason it isn't working.
var express = require('express');
var _ = require('underscore');
var mongoose = require('mongoose');
var podStore = require('./lib/pod-handler.js');
var podsLibrary = require('./lib/pods-library.js');
var podList = [];
var mongoPort = 27017;
var app = express();
var port = 3000;
var router = express.Router();
var pods = podsLibrary.list();
mongoose.connect('mongodb://localhost:'+mongoPort+'/pods');
router.route('/').get(function(request, response) {
//console.log('You hit an empty URL .. :(');
response.status(503).send("Service Unavailable");
});
router.route('/lib').get(function(request, response) {
//console.log('You hit an empty URL .. :(');
response.status(200).send("Cool beans!");
});
router.route('/pods/list').get(function(request, response){
if(!pods){
return response.status(503).send("Service Unavailable");
}
return response.status(200).send(makeReadableList(pods));
function makeReadableList(pods){
var podsHtml = " ";
_.each(pods, function(value, key){podsHtml = podsHtml + key});
return podsHtml;
}
});
router.route('/pods/add').post(function(request, response){
if (!request.query){
return response.status(400).send("Please give first name");
}
var payload = request.query;
if (!payload.firstName){
return response.status(400).send("give name");
}
podStore.save({
firstName: payload.firstName,
lastName: payload.lastName
}, function(){
return response.status(200).send(payload.firstName + " has been added!");
var space = " ";
_.each(pods, function(value, key) {
key + space;
return space + payload.firstName + payload.secondName;
});
});
});
router.route('/pods').get(function(request, response) {
//console.log("We reached the POD page -- Yay! :D");
response.status(200).send("Server unavailable");
});
app.use('/', router);
app.listen(port, function () {
console.log('App listening on port %s', port);
});
I've checked over my code countless times and I can't seem to find the problem.
Here's the pod-handler file.
var PodDoc = require('../models/pods.js');
module.exports = {
save: save
}
function save(pod, callback){
var podToSave = new PodDoc();
podToSave.firstName = pod.firstName;
podToSave.lastName = pod.lastName;
/*podToSave.skills = pod.skills;
podToSave.avatarUrl = pod.avatarUrl;
podToSave.address = {
number: pod.address.number,
lineOne: pod.address.lineOne,
lineTwo: pod.address.lineTwo,
postcode: pod.address.postcode
}
podToSave.phoneNumbers = {
mobile: pod.phoneNumbers.mobile,
landline: pod.phoneNumbers.landline
}*/
podToSave.save(function(err){
if(err){
console.log(err);
} else {
console.log("Working");
callback();
}
})
}

When I type in localhost:3000/pods/add?firstName='John' it's supposed to add it to the database
If i understand correctly, you want to open this url in browser, and expect to have a record John in database.
Change router request type to GET, this
router.route('/pods/add').post(/*omitted*/);
to this
router.route('/pods/add').get(/*omitted*/);
Server is expecting POST request, but browser cannot handle it without FORM element or ajax request, browsers usually uses GET request, i mean when you open your url, it send GET request to server

There may be a typo error as in the url you are using port 300 where as the port configured for localhost is 3000.
When I type in localhost:300/pods/add?firstName='John'

nodejs write after request end error

I am facing problem of write after request end in nodejs :
I have a server.js file , which sends request to other js file (say abc.js) which sends response back to server.js file and then server.js file writes the resoponse and then end response.
my problem is if I write response in abc.js and end it there only it works fine, but if it is in sererconf.js it doesn't.
Let me make it clear that I get this bug only when i send 20-30 requests at a time. I want to know the logic behind it, I searched a lot, but no nice answer found, any help will be appreciated.
server.js full code:
/* create HTTP server */
var httpd = http.createServer(function(req, res) {
res.setHeader('Access-Control-Allow-Origin', '*');
res.writeHead(200, {"Content-Type" : "application/json"});
}).listen(3800);
/* send request to the file mentioned in url*/
httpd.on('request', function(req, res) {
urll = __dirname + '/..' + req.url;
fs.exists(urll, function (exists) {
if(exists){
var server = require(urll);
server.get(req,res);
}
});
module.exports = {
result : function(result){
if(Array.isArray(result)){
for(var key in result){
result[key] = JSON.parse(result[key]);
}
}
result = JSON.stringify(result);
res.write(result ,function(err) { if(!err) res.end(); });
},
};
});
**apps.js code**:
var constants = require('./lib/constant.js');
var APP_PATH = constants.APP_PATH;
module.exports = {
get : function(req) {
req.on('data', function(chunk) {
var hash = chunk;
hash = JSON.parse(hash);
var id = hash.id;
dirPath = APP_PATH + id;
fs.exists( dirPath, function (exists) {
if(exists)
read_app_dir(dirPath);
else
taskDone([]);
});
});
}
};
function read_app_dir(app_dir){
fs.readdir(app_dir,function(err, list){
if (err) {
httpd.log.info('cannot read apps dir at s_apps = '+err);
}else{
create_new_obj(list,app_dir);
}
});
}
function create_new_obj(list, app_dir){
appFilesObj = [];
var i = 0;
list.forEach(function(file) {
i=i+1;
file = app_dir +'/' +file;
appFilesObj.push(file);
if(i == Object.keys(list).length)
read_app_files(appFilesObj);
});
}
function read_app_files(appFilesObj,app_dir){
var apps = [];
var i = 0;
if(Object.keys(appFilesObj).length > 0){
appFilesObj.forEach(function(appfile) {
read_file(appfile,function(data){ i=i+1;
apps.push(data);
if(i == Object.keys(appFilesObj).length)
taskDone(apps);
});
});
}else{
taskDone([]);
}
}
function read_file(file,callback){
fs.readFile(file,'utf8', function (err, data) {
if (err)
httpd.log.info('cannot read file at s_apps = '+err);
else
callback(data);
});
}
function taskDone(apps){
var httpd = require(__dirname + '/server.js');
httpd.result(apps);
}
if I do res.write and res.end in this file in taskDone() then it works fine.
Thanks in advance :)

The problem with above code was, that I was sending back response by calling an exported function of server.js
like this:
var httpd = require(__dirname + '/server.js');
httpd.result(apps);
where result() is the function which I have exported in server.js to write response and end response
Instead of this, now I added a callback support while calling function of other files (ex-apps.js), so that I "res.write" and "res.end()" only when the actually called function gives back the response.
(I am not writing the whole code , please refer above code for difference in both)
httpd.on('request', function(req, res) {
urll = __dirname + '/..' + req.url;
fs.exists(urll, function (exists) {
if(exists){
var server = require(urll);
server.get(req,res,function(result){
res.write(result);
res.end();
});
}
});
**apps.js**
get : function(req, callback) {
req.on('data', function(chunk) {
//when task is done and taskDone() function is called I just callback() the result
function taskDone(result){
callback(result);
}
}
}
When I was sending result back by calling a function of server.js and then writing the response...I don't know how..but somehow server was getting confused in multiple requests and saying "write after end" error...while the end was called by some other user's request.
I may be wrong, but this is what I concluded from this :)
I hope this may help others.

avoiding while loop when checking if file exists

I have a node application that reads an uploaded file like so:
router.route('/moduleUpload')
.post(function (request, response) {
request.files.file.originalname = request.files.file.originalname.replace(/ +?/g, '');
var media = new Media(request.files.file, './user_resources/module/' + request.body.module_id + '/');
if (!fs.existsSync(media.targetDir)) {
fs.mkdirSync(media.targetDir, 0777, function (err) {
if (err) {
console.log(err);
response.send("ERROR! Can't make the directory! \n"); // echo the result back
}
});
fs.chmodSync(media.targetDir, 0777);
}
moveFile(media);
var token = jwt.encode({
mediaObject: media
}, require('../secret')());
response.status(200).json(token);
});
Now when this file is uploaded and status code 200 is recieved my system then calls the following route:
router.route('/resourcePath/:encodedString')
.all(function (req, res) {
var decoded = jwt.decode(req.params.encodedString, require('../secret')());
var mediaObject = decoded.mediaObject;
var ext = mediaObject.file.originalname.substr(mediaObject.file.originalname.lastIndexOf('.'));
var path = 'app_server' + mediaObject.targetDir.substring(1) + mediaObject.fileName + ext;
var fileExist = false;
res.status(200).send(path)
});
Now for some reason this call is being called before the file is correctly in place which results in that sometimes my users cannot see the content.
To make sure the file was in the folder i thought of the following code to add:
var fileExist = false;
while (!fileExist) {
if (fs.existsSync('/var/www/learningbankapp/'+path)) {
fileExist = true;
}
}
However im not sure that this a good solution namly because it goes against node.js nature. So my question is, is there a better way to do it?