Extracting a JSON Object from a URL - json

We are attempting to extract a JSON Object from a URL through http requesting. However, when we consistently getting the "undefined" when we try to return the text. Is there a problem in the way that we are implementing the http request?
function getUserData(email) {
var pathURL = "/" + email + "/data"
var options = {
host: 'localhost',
port: 3000,
path: pathURL,
method: 'GET',
headers: {
accept: 'application/json'
}
};
var x = http.request(options, function(res){
console.log("Connected");
res.on('data', function(data){
console.log(data);
});
});
}

Close the http.request() by using
x.end();
Here a reference to a similar question.
Sending http request in node.js
Try logging error as:
req.on('error', function(err){
console.log('problem with request:',err.message);
});
Meanwhile check the documentation of http library as well.

The response body are data but not returning to x.
var body = []
request.on('data', function(chunk) {
body.push(chunk)
}).on('end', function() {
body = Buffer.concat(body).toString()
// all is done, you can now use body here
})

Related

Change the content type in the request headers

I am supposed to send data from an app to the server and the post method from that app is made using content type as application/json but it is plain text. I cannot update the app to change this header now. The current app is working as the data reaches PHP directly and PHP doesn't parse the incoming data which is specified as json.
import express from 'express'
var http = require('http')
const redirectionRoutes = express.Router()
redirectionRoutes.use(function(req, res, next) {
req.rawBody = ''
req.headers['content-type'] = 'text/plain'
req.on('data', function(chunk) {
req.rawBody += chunk
})
req.on('end', function() {
next()
})
})
redirectionRoutes.post(/^\/update_services\/.*$/, function(request, response) {
var data = request.rawBody
var dataLength = data.length
var options = {
hostname: 'localhost',
port: 80,
path: request.path,
method: 'POST',
json: false,
headers: {
'Content-Type': 'text/plain',
'Content-Length': dataLength
}
}
var buffer = ''
var req = http.request(options, function(res) {
res.on('data', function(chunk) {
buffer += chunk
})
res.on('end', function() {
response.send(buffer)
})
})
req.write(data)
req.end()
})
But in nodejs(my application), as the content type is specified as json, the body parser is parsing the data and as it's not json, I am getting an error:
SyntaxError: Unexpected token # in JSON at position 0
at JSON.parse (<anonymous>)
at createStrictSyntaxError (../node_modules/body-parser/lib/types/json.js:157:10)
at parse (../node_modules/body-parser/lib/types/json.js:83:15)
at /Users/../node_modules/body-parser/lib/read.js:116:18
at invokeCallback (/Users/../node_modules/body-parser/node_modules/raw-body/index.js:224:16)
at done (/Users/../node_modules/body-parser/node_modules/raw-body/index.js:213:7)
at IncomingMessage.onEnd (/Users/../node_modules/body-parser/node_modules/raw-body/index.js:273:7)
at emitNone (events.js:105:13)
at IncomingMessage.emit (events.js:207:7)
at endReadableNT (_stream_readable.js:1047:12)
Is there a way in nodejs/body parser to not to parse this incoming json and let is get into the function as plain text.
It is solved!!
I am exporting this module at the end of the app code along with other pages routers. So, the body-parser being called in previous libraries are being called if I didn't use in this particular router.

nodeJS - make HTTPS request, sending JSON data

I would like to send an HTTPS POST from one nodeJS server to another. I have some JSON data I would like to send with this request (populated by a html form).
How can I do this? I am aware of https.request() but there does not seem to be an option to include JSON as a part of the query. From my research it seems possible with an HTTP request, but not an HTTPS request. How can I solve this?
const pug = require('pug');
var cloudinary = require('cloudinary');
var express = require('express');
var multer = require('multer');
var upload = multer({ dest: 'uploads/' });
var request = require('request');
var bodyParser = require('body-parser');
var options = {
hostname: 'ec2-54-202-139-197.us-west-2.compute.amazonaws.com',
port: 443,
path: '/',
method: 'GET'
};
var app = express();
var parser = bodyParser.raw();
app.use(parser);
app.set('view engine', 'pug');
app.get('/', upload.single('avatar'), function(req, res) {
return res.render('index.pug');
});
app.get('/makeRequest*', function(req, res) {
query = req['query'];
/*
Here, I would like to send the contents of the query variable as JSON to the server specified in options.
*/
});
You can send JSON data through a POST http request with the native https node module, as stated in the documentation
All options from http.request() are valid.
So, taking the http.request() example you can do the following:
var postData = querystring.stringify({
'msg' : 'Hello World!'
});
var options = {
hostname: 'www.google.com',
port: 80,
path: '/upload',
method: 'POST',
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
'Content-Length': Buffer.byteLength(postData)
}
};
var req = https.request(options, (res) => {
console.log(`STATUS: ${res.statusCode}`);
console.log(`HEADERS: ${JSON.stringify(res.headers)}`);
res.setEncoding('utf8');
res.on('data', (chunk) => {
console.log(`BODY: ${chunk}`);
});
res.on('end', () => {
console.log('No more data in response.');
});
});
req.on('error', (e) => {
console.log(`problem with request: ${e.message}`);
});
// write data to request body
req.write(postData);
req.end();
You should edit postData to your desired JSON object
I believe the below is what you want. Using the request library. See comments in the code for my recommendations.
...
var options = {
hostname: 'ec2-54-202-139-197.us-west-2.compute.amazonaws.com',
port: 443,
path: '/',
method: 'POST',
json: true
};
...
//making a post request and sending up your query is better then putting it in the query string
app.post('/makeRequest', function(req, res) {
var query = req.body['query'];
//NOTE, you cannot use a GET request to send JSON. You'll need to use a POST request.
//(you may need to make changes on your other servers)
options.body = { payload: query };
request(options, function(err, response, body) {
if (err) {
//Handle error
return;
}
if (response.statusCode == 200) {
console.log('contents received');
}
});
});
as matt mentioned you need to use request
to send JSON object not JSON.Stringify so that at the server you can receive it using:
app.post('/makeRequest', function(req, res) {
console.log (req.body.param1);
}
Use the following code:
var request = require("request");
request({
'url':"http://www.url.com",
method: "POST",
json: true,
body: {'param1':'any value'}
}, function (error, resp, body) {
console.log ("check response.");
});

cors unexpected end of JSON input

I am parsing my json on end but I am still receiving this error.
'use strict';
const http = require('http');
const tools = require('./tools.js');
const server = http.createServer(function(request, response) {
console.log("received " + request.method + " request from " + request.headers.referer)
var body = "";
request.on('error', function(err) {
console.log(err);
}).on('data', function(chunk) {
body += chunk;
}).on('end', function() {
console.log("body " + body);
var data = JSON.parse(body); // trying to parse the json
handleData(data);
});
tools.setHeaders(response);
response.write('message for me');
response.end();
});
server.listen(8569, "192.168.0.14");
console.log('Server running at 192.168.0.14 on port ' + 8569);
Data being sent from the client:
var data = JSON.stringify({
operation: "shutdown",
timeout: 120
});
I successfully receive the json but I am unable to parse it.
Update:
I've updated the code to include the server code in its entirety.
To be perfectly clear, using the following code:
....
}).on('end', function() {
console.log("body " + body);
var json = JSON.parse(body); // trying to parse the json
handleData(json);
});
I get this:
However, this:
....
}).on('end', function() {
console.log("body " + body);
//var json = JSON.parse(body); // trying to parse the json
//handleData(json);
});
produces this
Can we see the server code, please?
Here is a working end-to-end example which is (more or less) what you are attempting, I believe.
"use strict";
const http = require('http');
/********************
Server Code
********************/
let data = {
operation: 'shutdown',
timeout: 120
};
const server = http.createServer((req, res) => {
res.writeHead(200, { 'Content-Type': 'application/json' });
res.write(JSON.stringify(data));
res.end();
});
server.listen(8888);
/********************
Client Code
********************/
let options = {
hostname: 'localhost',
port: 8888,
path: '/',
method: 'POST',
headers: {
'Accept': 'application/json'
}
};
let req = http.request(options, res => {
let buffer = '';
res.on('data', chunk => {
buffer += chunk;
});
res.on('end', () => {
let obj = JSON.parse(buffer);
console.log(obj);
// do whatever else with obj
});
});
req.on('error', err => {
console.error('Error with request:', err);
});
req.end(); // send the request.
It turns out that as this is a cross-origin(cors) request, it was trying to parse the data sent in the preflighted request.
I simply had to add an if to catch this
....
}).on('end', function() {
if (request.method !== 'OPTIONS') {
var data = JSON.parse(body);
handleData(data);
}
});
Further reading if you're interested: HTTP access control (CORS)
Put the identifiers in quotes.
{
"operation": "shutdown",
"timeout": 120
}
http://jsonlint.com/ Is a helpful resource.

How do I access HTTP POST data from meteor?

I have an Iron-router route with which I would like to receive lat/lng data through an HTTP POST request.
This is my attempt:
Router.map(function () {
this.route('serverFile', {
path: '/receive/',
where: 'server',
action: function () {
var filename = this.params.filename;
resp = {'lat' : this.params.lat,
'lon' : this.params.lon};
this.response.writeHead(200, {'Content-Type': 'application/json; charset=utf-8'});
this.response.end(JSON.stringify(resp));
}
});
});
But querying the server with:
curl --data "lat=12&lon=14" http://127.0.0.1:3000/receive
Returns {}.
Maybe params doesn't contain post data? I tried to inspect the object and the request but I can't find it.
The connect framework within iron-router uses the bodyParser middleware to parse the data that is sent in the body. The bodyParser makes that data available in the request.body object.
The following works for me:
Router.map(function () {
this.route('serverFile', {
path: '/receive/',
where: 'server',
action: function () {
var filename = this.params.filename;
resp = {'lat' : this.request.body.lat,
'lon' : this.request.body.lon};
this.response.writeHead(200, {'Content-Type':
'application/json; charset=utf-8'});
this.response.end(JSON.stringify(resp));
}
});
});
This gives me:
> curl --data "lat=12&lon=14" http://127.0.0.1:3000/receive
{"lat":"12","lon":"14"}
Also see here:
http://www.senchalabs.org/connect/bodyParser.html

how to get session from codeigniter with node.js

i'm writing application like social network where in my application can show status update and chat . when i search on internet i found node.js for long polling technology and i think i can use that for chat and streaming page in my application. but when i use node.js i have a stack
this is a technology i want to my project:
1) i'm using codeigniter for framework and mysql database in address localhost:81/myproject
2) and using node.js in port 127.0.0.1:8080 to chat and streaming page
this is code javascript server with node.js name is server.js
var sys = require("sys"),
http = require("http"),
url = require("url"),
path = require("path"),
fs = require("fs"),
events = require("events");
function load_static_file(uri, response) {
var filename = path.join(process.cwd(), uri);
path.exists(filename, function(exists) {
if(!exists) {
response.writeHead(404, {"Content-Type": "text/plain"});
response.write("404 Not Found\n");
response.end();
return;
}
fs.readFile(filename, "binary", function(err, file) {
if(err) {
response.writeHead(500, {"Content-Type": "text/plain"});
response.write(err + "\n");
response.end();
return;
}
response.writeHead(200);
response.write(file, "binary");
response.end();
});
});
}
var local_client = http.createClient(81, "localhost");
var local_emitter = new events.EventEmitter();
function get_users() {
var request = local_client.request("GET", "/myproject/getUser", {"host": "localhost"});
request.addListener("response", function(response) {
var body = "";
response.addListener("data", function(data) {
body += data;
});
response.addListener("end", function() {
var users = JSON.parse(body);
if(users.length > 0) {
local_emitter.emit("users", users);
}
});
});
request.end();
}
setInterval(get_users, 5000);
http.createServer(function(request, response) {
var uri = url.parse(request.url).pathname;
if(uri === "/stream") {
var listener = local_emitter.addListener("users", function(users) {
response.writeHead(200, { "Content-Type" : "text/plain" });
response.write(JSON.stringify(users));
response.end();
clearTimeout(timeout);
});
var timeout = setTimeout(function() {
response.writeHead(200, { "Content-Type" : "text/plain" });
response.write(JSON.stringify([]));
response.end();
local_emitter.removeListener(listener);
}, 10000);
}
else {
load_static_file(uri, response);
}
}).listen(8383);
sys.puts("Server running at http://localhost:8383/");
now in codeigniter side i making webservices on url http://localhost:81/myproject/getUser with response is json format and i access this with session auhtentication if not is redirect to login page.
[{"user_id":"2a20f5b923ffaea7927303449b8e76daee7b9b771316488679","token":"3m5biVJMjkCNDk79pGSo","username":"rakhacs","password":"*******","name_first":"rakha","name_middle":"","name_last":"cs","email_id":"email#gmail.com","picture":"img\/default.png","active":"1","online":"0","created_at":"2011-09-20 11:14:43","access":"2","identifier":"ae70c3b56df19a303a7693cdc265f743af5b0a6e"},{"user_id":"9a6e55977e906873830018d95c31d2bf664c2f211316493932","token":"RoUvvPyVt7bGaFhiMVmj","username":"ferdian","password":"*****","name_first":"willy","name_middle":"","name_last":";f;w","email_id":"email1#gmail.com","picture":"img\/default.png","active":"1","online":"0","created_at":"2011-09-20 11:47:20","access":"2","identifier":"1ccd4193fa6b56b96b3889e59c5205cc531177c9"}]
this is the point problem when i execute node server.js
i get error like this undefined:0
sysntaxerror:unexpected end of input
at object.parse(native)
i don't know about that error i think because i using session ? but i'm not sure.
when i test using test.js for testing my webservices
var http = require("http")
var options = {
host: 'localhost',
port: 81,
path: '/myproject/getUser',
method: 'GET'
};
var req = http.request(options, function(res) {
console.log('STATUS: ' + res.statusCode);
console.log('HEADERS: ' + JSON.stringify(res.headers));
res.setEncoding('utf8');
res.on('data', function (chunk) {
console.log('BODY: ' + chunk);
});
});
req.on('error', function(e) {
console.log('problem with request: ' + e.message);
});
// write data to request body
req.write('data\n');
req.write('data\n');
req.end();
and this is the output
problem with request: parse error
but when i using another webservice who has been response json format too and not using session that's work i can get the body response..if this problem is session how i can fix this?..this is can make me confused..thanks for your comment
hard to say but I would primary try to send an object in jSON and not directly an array. i.e. just encapsulate the array into an object:
{"data":[…]}
This "may" be causing the parse error.
Something else, for this purpose, it won't be bad to add the following to your responding PHP method:
header('Cache-Control: no-cache, must-revalidate');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Content-type: application/json');