I am using express.js and I need to make a call to HTTP GET request ,to fetch JSON data .Please suggest me some good node js/express js modules/lib to perform get/post request .
Node.js provides an extremely simple API for this functionality in the form of http.request.
var http = require('http');
//The url we want is: 'www.random.com/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
var options = {
host: 'www.random.com',
path: '/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
};
callback = function(response) {
var str = '';
//another chunk of data has been recieved, so append it to `str`
response.on('data', function (chunk) {
str += chunk;
});
//the whole response has been recieved, so we just print it out here
response.on('end', function () {
console.log(str);
});
}
http.request(options, callback).end();
Here I attach some more examples with POST and custom headers. If you don't need special things, I'd stick to the native code.
Besides, Request, Superagent or Requestify are pretty good libraries to use.
var express = require('express');
var app = express();
var fs = require('fs');
app.get('/', function (req, res) {
fs.readFile('./test.json', 'utf8', function (err, data) {
if (err) {
res.send({error: err});
}
res.send(data);
})
});
var server = app.listen(3001, function () {
console.log('Example app listening port 3001');
});
Related
I start learning Node.js and Express.js and I'm trying to create a simple API to list data from JSON file (using the GET method) and add a new user using the POST method.
the GET method works fine but the POST method does not work
when I request http://127.0.0.1:8080/listusers the API sends all users in a JSON file.
when I request http://127.0.0.1:8080/adduser the API has to add new User Info and send the new data back to the browser.
NOTE: I read all the questions on Stackoverflow about this problem but
non of them help me so I have to ask again.
the problem is when I request http://127.0.0.1:8080/adduser I get the following error
Cannot GET /adduser
here is the server.js:
var express = require('express');
var app = express();
var fs = require('fs');
var user = {
"user4" : {
"name" : "mounir",
"password" : "password4",
"profession" : "teacher",
"id": 4
}
};
app.post('/adduser', function (req, res) {
// First read existing users.
fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
data = JSON.parse( data );
data["user4"] = user["user4"];
console.log( data );
res.end(JSON.stringify(data) );
});
});
app.get('/listusers', function (req, res) {
fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
console.log(data);
res.end(data);
});
});
var server = app.listen(8080, function () {
var host = server.address().address;
var port = server.address().port;
console.log("listening at http://%s:%s", "0.0.0.0", port)
});
The answer is in the error. Cannot GET /adduser. Keyword GET! If you are making a post request, be sure you include the appropriate headers and that you are making a POST request, with a body, and not a GET request. For instance if you are using fetch:
const myInit = {
method: 'POST',
headers: myHeaders,
body: {
...
}
};
fetch("http://127.0.0.1:8080/adduser", myInit)
.then(res => {
...
});
I'm just starting to learn Node.js and right now, I'm trying to use a Node.js Application through cPanel to provide a JSON response when its app's URL is accessed.
When visiting the app's URL, it's evident that the Node.js server is working as it should. So after editing the main JS file, and restarting the Node.js app, changes are reflected when visiting the URL again.
My problem:
Within the function of https.createServer( function (req, res) {});, I want to make an HTTPS request to a PHP file elsewhere, which returns a JSON response. At the moment, I can't even get a response or error from any type of request with the PHP file.
var https = require('https');
var server = https.createServer(function (req, res) {
var message = "";
res.writeHead(200, {
'Content-Type': 'text/plain'
});
var options = {
host: "mydomain.com",
path: '/myPhpScript.php'
};
https.get(options, function(res) {
var bodyChunks = [];
res.on('data', function(chunk) {
bodyChunks.push(chunk);
}).on('end', function() {
var body = Buffer.concat(bodyChunks);
message += body;
})
}).on('error', function(e) {
message += e;
});
res.end(message);
});
server.listen();
As you can see, message would be what's displayed to the browser window, but it's empty. Nothing appears when visiting the App URL. Is it possible to make an HTTPS request with a Node.js HTTPS server?
Note:
I've also tried with native-request and axios and have experienced the same issue.
Server code:
var http = require('http');
var https = require("https");
var server = http.createServer(function (req, res) {
let call = new Promise((resolve, reject) => {
var options = {
host: "jarrenmorris.com",
port: 443,
path: '/gamesense/r6_db/1.json'
};
https.get(options, function (res) {
var bodyChunks = [];
res.on('data', function (chunk) {
bodyChunks.push(chunk);
}).on('end', function () {
resolve(Buffer.concat(bodyChunks));
});
}).on('error', function (e) {
reject(e);
});
});
call.then((data) => {
// do something here with the successful request/json
res.writeHead(200, {
'Content-Type': 'text/plain'
});
res.end(data);
}).catch((err) => {
// do something here with the failure request/json
// res.write("ERROR:");
res.end(err);
});
});
server.listen(8081, "127.0.0.1", () => {
console.log(`Server listen on ${server.address().address}:${server.address().port} `);
});
Response:
{"name":"tim","age":"42"}
First thing i noticed, while i tried to run your code was, you cant establish a connection to your node.js.
The reason for this was you use the https module, but didnt specify an certificates/keyfiles. Skip this, and work with http till you get the result you want.
Then i wrapped you https request to the external api/file in a promise.
This allows a simple chaining and better readability of the code.
When the promises resolves/fullfill, we answer the request on the http server with the data we received from the external request.
The res.end in your code (where you put it) made no sense, since you didnt wait for the external request to complete. Thats the reason why its nothing is shown in the browser window.
I am troubling with nodejs proxy server modified(write) response.
I want to achieve auto login for one site via node proxy server and for that i have to query in database then i can modified response but it seems req ended before req.write and getting Error: write after end
Below is my implementation so far.
var express = require('express');
var proxy = require('http-proxy-middleware');
var options = {
target: 'http://example.com/', // target host
changeOrigin: true,
onProxyReq: function onProxyReq(proxyReq, req, res) {
var _write = res.write;
var body = "";
proxyReq.on('data', function(data) {
data = data.toString('utf-8');
body += data;
});
res.write = function (data) {
try{
//I have database query here instead of setTimeout
setTimeout(function(){
/* Modified response here and write */
_write.call(res, data); //can't write because req already end
},3000);
} catch (err) {
console.log('err',err);
}
}
}
}
// create the proxy (without context)
var exampleProxy = proxy(options);
// mount `exampleProxy` in web server
var app = express();
app.use('/', exampleProxy);
app.listen(8080);
Can anyone guide me how to achieve this ?
I am new to nodeJS, i want to fetch data from webApi using nodeJS, for instance, when i make a call to the
mydomain/getAllStudents
i want all the students data and when i do
mydomain/student/4
then i want only the data of the student with the ID=2
-challenge-
using express i can specify the route like this
var app=express();
app.get('/getAllStudents',(request,response)=>{
console.log('we are listening !!!');
}).listen(8080);
but when i try to make a call inside the callback function, i not able to get the value, my complete code
var http=require('http');
var express=require('express');
var app=express();
var options={host: '172.17.144.6',
port: 8394,
path: '/api/Masterdata/getAllStudents',
method: 'GET'}
app.get('/getAllStudents',(request,response)=>{
http.get(options,(res)=>{
res.on('data', function (chunk) {
console.log('BODY: ' + chunk);
});
});
console.log('we are listening !!!');
}).listen(8080);
what i am trying to achieve is, when i hit mydomain/getAllStudents i want to get all the data. how can i do this with nodeJS? can i do this with nodeJS statisfying my requirement?
So basically you want to expose the data through express after parsing them from another API.
You can do like this:
To make the call from node js you can use this library:
node-rest-client
var Client = require('node-rest-client').Client;
var remoteURL = "172.17.144.6:8394/api/Masterdata/getAllStudents";
var express = require('express');
var students = express.Router();
students.route('/getAllStudents')
.get(function(req, res) {
client.get(remoteURL, function (data, response) {
console.log(data);
if(response.statusCode === 200)
res.status(200).send(data);
});
});
I've got an audio file which I post to a server for translation. I've managed to create a request in postman, but I do not know how to write the file to this server. Below is the code I have got so far:
var http = require("https");
var options = {}
var req = http.request(options, function (res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
var body = Buffer.concat(chunks);
console.log(body.toString());
});
});
options{} is filled with method/hostname/port ofcourse. In postman I add "binary" file, but I cannot figger out how to write a file to the request in Node JS.
One solution that would easily fit into your current program without too much work is to make use of the form-data module on npm.
The form-data module makes ease of multipart requests in node. The following is a simple example of how to use.
var http = require("https");
var FormData = require('form-data');
var fs = require('fs')
var form = new FormData();
form.append('my_field', fs.createReadStream('my_audio.file'));
var options = {
host: 'your.host',
port: 443,
method: 'POST',
// IMPORTANT!
headers: form.getHeaders()
}
var req = http.request(options, function (res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
var body = Buffer.concat(chunks);
console.log(body.toString());
});
});
// Pipe form to request
form.pipe(req);
In a "real-world" scenario you would want to do a lot more error checking. Also, there are plenty of other http clients on npm that make this process easy as well (the request module uses form-data BTW). Check out request, and got if you are interested.
For sending a binary request the fundamentals are still the same, req is a writable stream. As such, you can pipe data into the stream, or write directly with req.write(data). Here's an example.
var http = require('https');
var fs = require('fs');
var options = {
// ...
headers: {
'Content-Type': 'application/octet-stream'
}
}
var req = http.request(options, function (res) {
var chunks = [];
res.on("data", function (chunk) {
chunks.push(chunk);
});
res.on("end", function () {
var body = Buffer.concat(chunks);
console.log(body.toString());
});
});
var audioFile = fs.createReadStream('my_audio.file', { encoding: 'binary' });
audioFile.pipe(req);
Note, that if you use the write method explicitly req.write(data) you must call req.end(). Also, the you may want to take a look at the encoding options for Node's Buffer (docs).
You can use the request package on npm.
Install the request module from npm:
npm install request --save
Then use the request module to send your request.
Have a look at https://www.npmjs.com/package/request for details on implementation.
Thanks #undefined, your answer really helped me.
I am posting my solution which worked for me to send file to another server using axios. Ignore the type specifications, I had Typescript enabled for my project.
export const fileUpload: RequestHandler = async (req: Request, res: Response, next: NextFunction) => {
const chunks: any[] = [];
req.on('data', (chunk) => chunks.push(chunk));
req.on('end', () => {
const data = Buffer.concat(chunks);
axios.put("ANOTHER_SERVER_URL", data).then((response) => {
console.log('Success', response);
}).catch(error => {
console.log('Failure', error);
});
});
return res.status(200).json({});
};
Thanks, hope it helps!