I have 2 files in Node js .I want to merge these 2, but I am facing problem..
This file calls function from python file
const app = express()
let runPy = new Promise(function(success, nosuccess) {
const { spawn } = require('child_process');
const pyprog = spawn('python', ['./ml.py']);
pyprog.stdout.on('data', function(data) {
success(data);
});
pyprog.stderr.on('data', (data) => {
nosuccess(data);
});
});
app.get('/', (req, res) => {
res.write('welcome\n');
runPy.then(function(testMLFunction) {
console.log(testMLFunction.toString());
res.end(testMLFunction);
});
})
app.listen(4000, () => console.log('Application listening on port 4000!'))
python file ml.py
def testMLFunction():
return "hello from Python"
print(testMLFunction())
Below file works on button click with post method
var fs = require('fs');
var server = http.createServer(function (req, res) {
if (req.method === "GET") {
res.writeHead(200, { "Content-Type": "text/html" });
fs.createReadStream("./form.html", "UTF-8").pipe(res);
} else if (req.method === "POST") {
var result = "";
req.on("data", function (chunk) {
console.log(chunk.toString());
result = chunk;
//body=body.toUpperCase;
});
req.on("end", function(){
res.writeHead(200, { "Content-Type": "text/html" });
res.end(result);
});
}
}).listen(3000);
how can I do that..
There are several things wrong here. I will explain as plain as possible.
You forgot to add in your code var express = require('express')
The promise you made, runPy, must be wrapped in a function, whereas your approach will instantly start the promise upon loading the script itself.
You are resolving/rejecting on first incoming output, you shouldn't do that because you won't be able to know what really happened in the shell. You need to store those output lines, this is the only way of you knowing what the script tells you.
In runPy you must resolve/reject upon pyprogr close event.
You cannot access directly the method of another script, no matter what that kind of file that is a py, sh, bat, js. However, you can access internal functions of it by passing arguments to the shell, and of course, that script must have the logic required to deal with those arguments.
When using spawn/exec you must keep in mind that YOU ARE NOT the user executing the script, the node user is, so different outcomes may occur.
Most importantly, your targeted script must PRINT/ECHO to shell, no returns! The best approach would be to print some json string, and parse it in javascript after the shell is closed, so you can have access to an object instead of a string.
Below you will find a demo for your use case, i changed the python file so it can print something.
ml.py
print('I\'m the output from ml.py')
index.js
const express = require('express');
const app = express()
let runPy = function () { // the promise is now wrapped in a function so it won't trigger on script load
return new Promise(function (success, nosuccess) {
const {spawn} = require('child_process');
const pyprog = spawn('python', ['./ml.py'], {shell: true}); // add shell:true so node will spawn it with your system shell.
let storeLines = []; // store the printed rows from the script
let storeErrors = []; // store errors occurred
pyprog.stdout.on('data', function (data) {
storeLines.push(data);
});
pyprog.stderr.on('data', (data) => {
storeErrors.push(data);
});
pyprog.on('close', () => {
// if we have errors will reject the promise and we'll catch it later
if (storeErrors.length) {
nosuccess(new Error(Buffer.concat(storeErrors).toString()));
} else {
success(storeLines);
}
})
})
};
let path = require('path');
app.use(express.json());
app.use(express.urlencoded({ extended: true })); // you need to set this so you can catch POST requests
app.all('/', (req, res) => { // i've change this from .get to .all so you can catch both get and post requests here
console.log('post params', req.body);
if(req.body.hasOwnProperty('btn-send')){
runPy()
.then(function (pyOutputBuffer) {
let message = 'You sent this params:\n' +JSON.stringify(req.body, null,2) + '\n';
message += Buffer.concat(pyOutputBuffer).toString();
res.end(message);
})
.catch(console.log)
}else{
res.sendFile(path.join(__dirname,'form.html')); // you need an absolute path to 'file.html'
}
});
app.listen(4000, () => console.log('Application listening on port 4000!'));
form.html
<div>hello there</div>
<form action="/" method="post">
<input type="text" value="" name="some-text"/>
<button type="submit" value="1" name="btn-send" >Press me!</button>
</form>
I ran into a problem and I feel that node-http-proxy is changing my target links. I got a few examples below.
I am using express as my server and using Metaweather API .
The problem is that I was able to get data from the endpoints below
https://www.metaweather.com/api/location/2487956/
https://www.metaweather.com/api/location/2487956/2013/4/30/
But when I try to call the API from https://www.metaweather.com/api/location/search/?lattlong=36.96,-122.02
It fails with status code 500 which I lead me thinking that node-http-proxy added some values after 122.02 as it was not closed with /
server.js
const express = require("express");
const next = require("next");
const dev = process.env.NODE_ENV !== "production";
const app = next({ dev });
const handle = app.getRequestHandler();
const httpProxy = require("http-proxy");
const proxyOptions = {
changeOrigin: true
};
const apiProxy = httpProxy.createProxyServer(proxyOptions);
const apiUrl =
"https://www.metaweather.com/api/location/search/?lattlong=36.96,-122.02";
/*
https://www.metaweather.com/api/location/search/?lattlong=36.96,-122.02 - failed with 500
https://www.metaweather.com/api/location/2487956/ - passed
https://www.metaweather.com/api/location/2487956/2013/4/30/ - passed
*/
app
.prepare()
.then(() => {
const server = express();
server.use("/api", (req, res) => {
console.log("Going to call this API " + apiUrl);
apiProxy.web(req, res, { target: apiUrl });
});
server.get("*", (req, res) => {
return handle(req, res);
});
server.listen(3000, err => {
if (err) throw err;
console.log("> Ready on http://localhost:3000");
});
})
.catch(ex => {
console.error(ex.stack);
process.exit(1);
});
Thanks for looking into this question.
I have reproduced where this is happening in node-http-proxy.
In common.js there is a function called urlJoin which is appending the req.url to the end of the target url.
I'm not exactly sure what the intent is, but it's a start.
Here's my test:
const urlJoin = function() {
//
// We do not want to mess with the query string. All we want to touch is the path.
//
var args = Array.prototype.slice.call(arguments),
lastIndex = args.length - 1,
last = args[lastIndex],
lastSegs = last.split('?'),
retSegs;
args[lastIndex] = lastSegs.shift();
//
// Join all strings, but remove empty strings so we don't get extra slashes from
// joining e.g. ['', 'am']
//
retSegs = [
args.filter(Boolean).join('/')
.replace(/\/+/g, '/')
.replace('http:/', 'http://')
.replace('https:/', 'https://')
];
// Only join the query string if it exists so we don't have trailing a '?'
// on every request
// Handle case where there could be multiple ? in the URL.
retSegs.push.apply(retSegs, lastSegs);
return retSegs.join('?')
};
let path = urlJoin('/api/location/search/?lattlong=36.96,-122.02', '/');
console.log(path);
// /api/location/search/?lattlong=36.96,-122.02/
I am wondering if there is any disadvantage to starting a server in a process and then running tests against that server in the same process.
Obviously there are some performance concerns, but if we are testing accuracy instead of performance, are there any major concerns with code like the following?
var fs = require('fs');
var path = require('path');
var http = require('http');
var supertest = require('supertest');
var assert = require('assert');
describe('#Test - handleXml()*', function() {
var self = this;
var server;
var payload = ''; // stringified XML
var xmlPath = path.resolve('test', 'test_data', 'xml_payloads', 'IVR_OnDemandErrorCode.xml');
before(function(done) {
var config = self.config = require('univ-config')(module, this.test.parent.title, 'config/test-config');
server = createServer().on('listening', function() {
done(null);
});
});
beforeEach(function(done) {
fs.readFile(xmlPath, 'utf8', function(err, content) {
assert(err == null);
payload = content;
done();
});
});
it('should accept request Content-type "text/xml or application/xml"', function(done) {
supertest(server)
.post('/event')
.set('Content-Type', 'application/xml')
.send(payload)
.expect(200, done);
});
it('should transform XML payload into JSON object', function(done) {
supertest(server)
.post('/event')
.set('Content-type', 'application/xml')
.send(payload)
.expect(200)
.end(function(err, res) {
assert(err == null,'Error is not null');
var jsonifiedXml = JSON.parse(res.text);
assert(typeof jsonifiedXml === 'object','jsonifiedXml not an object');
done();
});
});
describe('JSONified XML', function() {
it('should have proper key casing', function(done) {
supertest(server)
.post('/event')
.set('Content-type', 'application/xml')
.send(payload)
.expect(200)
.end(function(err, res) {
assert(err == null);
var payload = JSON.parse(res.text);
payload = payload.events[0].data;
assert(payload.hasOwnProperty('ppv'),'Bad value for ppv');
assert(payload.hasOwnProperty('mac'),'Bad value for mac');
assert(payload.hasOwnProperty('appName'),'Bad value for appName');
assert(payload.hasOwnProperty('divisionId'),'Bad value for divisionId');
assert(payload.hasOwnProperty('callTime'),'Bad value for callTime');
assert(payload.hasOwnProperty('callDate'),'Bad value for callDate');
assert(payload.hasOwnProperty('ivrLOB'),'Bad value for ivrLOB');
done();
});
});
});
});
function createServer(opts) {
//Note: this is a good pattern, definitely
var handleXml = require(path.resolve('lib', 'handleXml'));
var server = http.createServer(function(req, res) {
handleXml(req, res, function(err) {
res.statusCode = err ? (err.status || 500) : 200;
res.end(err ? err.message : JSON.stringify(req.body));
});
});
server.listen(5999); //TODO: which port should this be listening on? a unused port, surely
return server;
}
That's the standard way of testing a the http endpoints in a node application. But you are not going to want to have a createServer() function in each test. You will have a common function that creates a server that you can use through out your application, including to start the production server.
You right in noticing the having the server listen to a port doesn't actually do anything for you.
For this reason, it's common to have what I call an application factory that starts everything about a server, but does not listen to a port. That way I can access the server from a test or a script. The production app gets booted from a minimal index file:
var createServer = require('./AppFactory');
var server = createServer();
server.listen(5999);
Can we get the variables in the query string in Node.js just like we get them in $_GET in PHP?
I know that in Node.js we can get the URL in the request. Is there a method to get the query string parameters?
Since you've mentioned Express.js in your tags, here is an Express-specific answer: use req.query. E.g.
var express = require('express');
var app = express();
app.get('/', function(req, res){
res.send('id: ' + req.query.id);
});
app.listen(3000);
In Express it's already done for you and you can simply use req.query for that:
var id = req.query.id; // $_GET["id"]
Otherwise, in NodeJS, you can access req.url and the builtin url module to url.parse it manually:
var url = require('url');
var url_parts = url.parse(request.url, true);
var query = url_parts.query;
In Express, use req.query.
req.params only gets the route parameters, not the query string parameters. See the express or sails documentation:
(req.params) Checks route params, ex: /user/:id
(req.query) Checks query string params, ex: ?id=12 Checks urlencoded body params
(req.body), ex: id=12 To utilize urlencoded request bodies, req.body should be an object. This can be done by using the _express.bodyParser middleware.
That said, most of the time, you want to get the value of a parameter irrespective of its source. In that case, use req.param('foo'). Note that this has been deprecated as of Express 4: http://expressjs.com/en/4x/api.html#req.param
The value of the parameter will be returned whether the variable was in the route parameters, query string, or the encoded request body.
Side note- if you're aiming to get the intersection of all three types of request parameters (similar to PHP's $_REQUEST), you just need to merge the parameters together-- here's how I set it up in Sails. Keep in mind that the path/route parameters object (req.params) has array properties, so order matters (although this may change in Express 4)
For Express.js you want to do req.params:
app.get('/user/:id', function(req, res) {
res.send('user' + req.params.id);
});
I learned from the other answers and decided to use this code throughout my site:
var query = require('url').parse(req.url,true).query;
Then you can just call
var id = query.id;
var option = query.option;
where the URL for get should be
/path/filename?id=123&option=456
//get query¶ms in express
//etc. example.com/user/000000?sex=female
app.get('/user/:id', function(req, res) {
const query = req.query;// query = {sex:"female"}
const params = req.params; //params = {id:"000000"}
})
If you are using ES6 and Express, try this destructuring approach:
const {id, since, fields, anotherField} = request.query;
In context:
const express = require('express');
const app = express();
app.get('/', function(req, res){
const {id, since, fields, anotherField} = req.query;
});
app.listen(3000);
You can use default values with destructuring too:
// sample request for testing
const req = {
query: {
id: '123',
fields: ['a', 'b', 'c']
}
}
const {
id,
since = new Date().toString(),
fields = ['x'],
anotherField = 'default'
} = req.query;
console.log(id, since, fields, anotherField)
There are 2 ways to pass parameters via GET method
Method 1 :
The MVC approach where you pass the parameters like /routename/:paramname
In this case you can use req.params.paramname to get the parameter value For Example refer below code where I am expecting Id as a param
link could be like : http://myhost.com/items/23
var express = require('express');
var app = express();
app.get("items/:id", function(req, res) {
var id = req.params.id;
//further operations to perform
});
app.listen(3000);
Method 2 :
General Approach : Passing variables as query string using '?' operator
For Example refer below code where I am expecting Id as a query parameter
link could be like : http://myhost.com/items?id=23
var express = require('express');
var app = express();
app.get("/items", function(req, res) {
var id = req.query.id;
//further operations to perform
});
app.listen(3000);
You should be able to do something like this:
var http = require('http');
var url = require('url');
http.createServer(function(req,res){
var url_parts = url.parse(req.url, true);
var query = url_parts.query;
console.log(query); //{Object}
res.end("End")
})
UPDATE 4 May 2014
Old answer preserved here: https://gist.github.com/stefek99/b10ed037d2a4a323d638
1) Install express: npm install express
app.js
var express = require('express');
var app = express();
app.get('/endpoint', function(request, response) {
var id = request.query.id;
response.end("I have received the ID: " + id);
});
app.listen(3000);
console.log("node express app started at http://localhost:3000");
2) Run the app: node app.js
3) Visit in the browser: http://localhost:3000/endpoint?id=something
I have received the ID: something
(many things have changed since my answer and I believe it is worth keeping things up to date)
Express specific simple ways to fetch
query strings(after ?) such as https://...?user=abc&id=123
var express = require('express');
var app = express();
app.get('/', function(req, res){
res.send('id: ' + req.query.id);
});
app.listen(3000);
query params such as https://.../get/users/:id
var express = require('express');
var app = express();
app.get('/get/users/:id', function(req, res){
res.send('id: ' + req.params.id);
});
app.listen(3000);
A small Node.js HTTP server listening on port 9080, parsing GET or POST data and sending it back to the client as part of the response is:
var sys = require('sys'),
url = require('url'),
http = require('http'),
qs = require('querystring');
var server = http.createServer(
function (request, response) {
if (request.method == 'POST') {
var body = '';
request.on('data', function (data) {
body += data;
});
request.on('end',function() {
var POST = qs.parse(body);
//console.log(POST);
response.writeHead( 200 );
response.write( JSON.stringify( POST ) );
response.end();
});
}
else if(request.method == 'GET') {
var url_parts = url.parse(request.url,true);
//console.log(url_parts.query);
response.writeHead( 200 );
response.write( JSON.stringify( url_parts.query ) );
response.end();
}
}
);
server.listen(9080);
Save it as parse.js, and run it on the console by entering "node parse.js".
Whitequark responded nicely. But with the current versions of Node.js and Express.js it requires one more line. Make sure to add the 'require http' (second line). I've posted a fuller example here that shows how this call can work. Once running, type http://localhost:8080/?name=abel&fruit=apple in your browser, and you will get a cool response based on the code.
var express = require('express');
var http = require('http');
var app = express();
app.configure(function(){
app.set('port', 8080);
});
app.get('/', function(req, res){
res.writeHead(200, {'content-type': 'text/plain'});
res.write('name: ' + req.query.name + '\n');
res.write('fruit: ' + req.query.fruit + '\n');
res.write('query: ' + req.query + '\n');
queryStuff = JSON.stringify(req.query);
res.end('That\'s all folks' + '\n' + queryStuff);
});
http.createServer(app).listen(app.get('port'), function(){
console.log("Express server listening on port " + app.get('port'));
})
It is so simple:
Example URL:
http://stackoverflow.com:3000/activate_accountid=3&activatekey=$2a$08$jvGevXUOvYxKsiBt.PpMs.zgzD4C/wwTsvjzfUrqLrgS3zXJVfVRK
You can print all the values of query string by using:
console.log("All query strings: " + JSON.stringify(req.query));
Output
All query strings : { "id":"3","activatekey":"$2a$08$jvGevXUOvYxKsiBt.PpMs.zgzD4C/wwTsvjz
fUrqLrgS3zXJVfVRK"}
To print specific:
console.log("activatekey: " + req.query.activatekey);
Output
activatekey: $2a$08$jvGevXUOvYxKsiBt.PpMs.zgzD4C/wwTsvjzfUrqLrgS3zXJVfVRK
You can use
request.query.<varible-name>;
You can use with express ^4.15.4:
var express = require('express'),
router = express.Router();
router.get('/', function (req, res, next) {
console.log(req.query);
});
Hope this helps.
In express.js you can get it pretty easy, all you need to do in your controller function is:
app.get('/', (req, res, next) => {
const {id} = req.query;
// rest of your code here...
})
And that's all, assuming you are using es6 syntax.
PD. {id} stands for Object destructuring, a new es6 feature.
app.get('/user/:id', function(req, res) {
res.send('user' + req.params.id);
});
You can use this or you can try body-parser for parsing special element from the request parameters.
consider this url -> /api/endpoint/:id?name=sahil
here id is param where as name is query. You can get this value in nodejs like this
app.get('/api/endpoint/:id', (req, res) => {
const name = req.query.name; // query
const id = req.params.id //params
});
There are many answers here regarding accessing the query using request.query however, none have mentioned its type quirk. The query string type can be either a string or an array, and this type is controlled by the user.
For instance using the following code:
const express = require("express");
const app = express();
app.get("/", function (req, res) {
res.send(`Your name is ${(req.query.name || "").length} characters long`);
});
app.listen(3000);
Requesting /?name=bob will return Your name is 3 characters long but requesting /?name=bob&name=jane will return Your name is 2 characters long because the parameter is now an array ['bob', 'jane'].
Express offers 2 query parsers: simple and extended, both will give you either a string or an array. Rather than checking a method for possible side effects or validating types, I personally think you should override the parser to have a consistent type: all arrays or all strings.
const express = require("express");
const app = express();
const querystring = require("querystring");
// if asArray=false only the first item with the same name will be returned
// if asArray=true all items will be returned as an array (even if they are a single item)
const asArray = false;
app.set("query parser", (qs) => {
const parsed = querystring.parse(qs);
return Object.entries(parsed).reduce((previous, [key, value]) => {
const isArray = Array.isArray(value);
if (!asArray && isArray) {
value = value[0];
} else if (asArray && !isArray) {
value = [value];
}
previous[key] = value;
return previous;
}, {});
});
app.get("/", function (req, res) {
res.send(`Your name is ${(req.query.name || "").length} characters long`);
});
app.listen(3000);
So, there are two ways in which this "id" can be received:
1) using params: the code params will look something like :
Say we have an array,
const courses = [{
id: 1,
name: 'Mathematics'
},
{
id: 2,
name: 'History'
}
];
Then for params we can do something like:
app.get('/api/posts/:id',(req,res)=>{
const course = courses.find(o=>o.id == (req.params.id))
res.send(course);
});
2) Another method is to use query parameters.
so the url will look something like ".....\api\xyz?id=1" where "?id=1" is the query part. In this case we can do something like:
app.get('/api/posts',(req,res)=>{
const course = courses.find(o=>o.id == (req.query.id))
res.send(course);
});
In case you want to avoid express, use this example:
var http = require('http');
const url = require('url');
function func111(req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
var q = url.parse(req.url, true);
res.end("9999999>>> " + q.query['user_name']);
}
http.createServer(func111).listen(3000);
usage:
curl http://localhost:3000?user_name=user1
by yl
you can use url module to collect parameters by using url.parse
var url = require('url');
var url_data = url.parse(request.url, true);
var query = url_data.query;
In expressjs it's done by,
var id = req.query.id;
Eg:
var express = require('express');
var app = express();
app.get('/login', function (req, res, next) {
console.log(req.query);
console.log(req.query.id); //Give parameter id
});
If you ever need to send GET request to an IP as well as a Domain (Other answers did not mention you can specify a port variable), you can make use of this function:
function getCode(host, port, path, queryString) {
console.log("(" + host + ":" + port + path + ")" + "Running httpHelper.getCode()")
// Construct url and query string
const requestUrl = url.parse(url.format({
protocol: 'http',
hostname: host,
pathname: path,
port: port,
query: queryString
}));
console.log("(" + host + path + ")" + "Sending GET request")
// Send request
console.log(url.format(requestUrl))
http.get(url.format(requestUrl), (resp) => {
let data = '';
// A chunk of data has been received.
resp.on('data', (chunk) => {
console.log("GET chunk: " + chunk);
data += chunk;
});
// The whole response has been received. Print out the result.
resp.on('end', () => {
console.log("GET end of response: " + data);
});
}).on("error", (err) => {
console.log("GET Error: " + err);
});
}
Don't miss requiring modules at the top of your file:
http = require("http");
url = require('url')
Also bare in mind that you may use https module for communicating over secured domains and ssl. so these two lines would change:
https = require("https");
...
https.get(url.format(requestUrl), (resp) => { ......
do like me
npm query-string
import queryString from "query-string";
export interface QueryUrl {
limit?: number;
range?: string;
page?: number;
filed?: string;
embody?: string;
q?: string | object;
order?: number;
sort?: string;
}
let parseUri: QueryUrl = queryString.parse(uri.query);
I am using MEANJS 0.6.0 with express#4.16, it's good
Client:
Controller:
var input = { keyword: vm.keyword };
ProductAPi.getOrder(input)
services:
this.getOrder = function (input) {return $http.get('/api/order', { params: input });};
Server
routes
app.route('/api/order').get(products.order);
controller
exports.order = function (req, res) {
var keyword = req.query.keyword
...