Is it possible to use jQuery selectors/DOM manipulation on the server-side using Node.js?
20 Answers
Update (27-Jun-18): It looks like there was a major update to jsdom
that causes the original answer to no longer work. I found this answer that explains how to use jsdom
now. I've copied the relevant code below.
var jsdom = require("jsdom");
const { JSDOM } = jsdom;
const { window } = new JSDOM();
const { document } = (new JSDOM('')).window;
global.document = document;
var $ = jQuery = require('jquery')(window);
Note: The original answer fails to mention that it you will need to install jsdom as well using npm install jsdom
Update (late 2013): The official jQuery team finally took over the management of the jquery
package on npm:
npm install jquery
Then:
require("jsdom").env("", function (err, window) {
if (err) {
console.error(err);
return;
}
var $ = require("jquery")(window);
});
Yes you can, using a library I created called nodeQuery
var Express = require('express')
, dnode = require('dnode')
, nQuery = require('nodeQuery')
, express = Express.createServer();
var app = function ($) {
$.on('ready', function () {
// do some stuff to the dom in real-time
$('body').append('Hello World');
$('body').append('<input type="text" />');
$('input').live('click', function () {
console.log('input clicked');
// ...
});
});
};
nQuery
.use(app);
express
.use(nQuery.middleware)
.use(Express.static(__dirname + '/public'))
.listen(3000);
dnode(nQuery.middleware).listen(express);
At the time of writing there also is the maintained Cheerio.
Fast, flexible, and lean implementation of core jQuery designed specifically for the server.
A simple crawler using Cheerio
This is my formula to make a simple crawler in Node.js. It is the main reason for wanting to do DOM manipulation on the server side and probably it's the reason why you got here.
First, use request
to download the page to be parsed. When the download is complete, handle it to cheerio
and begin DOM manipulation just like using jQuery.
Working example:
var
request = require('request'),
cheerio = require('cheerio');
function parse(url) {
request(url, function (error, response, body) {
var
$ = cheerio.load(body);
$('.question-summary .question-hyperlink').each(function () {
console.info($(this).text());
});
})
}
parse('http://stackoverflow.com/');
This example will print to the console all top questions showing on SO home page. This is why I love Node.js and its community. It couldn't get easier than that :-)
Install dependencies:
npm install request cheerio
And run (assuming the script above is in file crawler.js
):
node crawler.js
Encoding
Some pages will have non-english content in a certain encoding and you will need to decode it to UTF-8
. For instance, a page in brazilian portuguese (or any other language of latin origin) will likely be encoded in ISO-8859-1
(a.k.a. "latin1"). When decoding is needed, I tell request
not to interpret the content in any way and instead use iconv-lite
to do the job.
Working example:
var
request = require('request'),
iconv = require('iconv-lite'),
cheerio = require('cheerio');
var
PAGE_ENCODING = 'utf-8'; // change to match page encoding
function parse(url) {
request({
url: url,
encoding: null // do not interpret content yet
}, function (error, response, body) {
var
$ = cheerio.load(iconv.decode(body, PAGE_ENCODING));
$('.question-summary .question-hyperlink').each(function () {
console.info($(this).text());
});
})
}
parse('http://stackoverflow.com/');
Before running, install dependencies:
npm install request iconv-lite cheerio
And then finally:
node crawler.js
Following links
The next step would be to follow links. Say you want to list all posters from each top question on SO. You have to first list all top questions (example above) and then enter each link, parsing each question's page to get the list of involved users.
When you start following links, a callback hell can begin. To avoid that, you should use some kind of promises, futures or whatever. I always keep async in my toolbelt. So, here is a full example of a crawler using async:
var
url = require('url'),
request = require('request'),
async = require('async'),
cheerio = require('cheerio');
var
baseUrl = 'http://stackoverflow.com/';
// Gets a page and returns a callback with a $ object
function getPage(url, parseFn) {
request({
url: url
}, function (error, response, body) {
parseFn(cheerio.load(body))
});
}
getPage(baseUrl, function ($) {
var
questions;
// Get list of questions
questions = $('.question-summary .question-hyperlink').map(function () {
return {
title: $(this).text(),
url: url.resolve(baseUrl, $(this).attr('href'))
};
}).get().slice(0, 5); // limit to the top 5 questions
// For each question
async.map(questions, function (question, questionDone) {
getPage(question.url, function ($$) {
// Get list of users
question.users = $$('.post-signature .user-details a').map(function () {
return $$(this).text();
}).get();
questionDone(null, question);
});
}, function (err, questionsWithPosters) {
// This function is called by async when all questions have been parsed
questionsWithPosters.forEach(function (question) {
// Prints each question along with its user list
console.info(question.title);
question.users.forEach(function (user) {
console.info('\t%s', user);
});
});
});
});
Before running:
npm install request async cheerio
Run a test:
node crawler.js
Sample output:
Is it possible to pause a Docker image build?
conradk
Thomasleveil
PHP Image Crop Issue
Elyor
Houston Molinar
Add two object in rails
user1670773
Makoto
max
Asymmetric encryption discrepancy - Android vs Java
Cookie Monster
Wand Maker
Objective-C: Adding 10 seconds to timer in SpriteKit
Christian K Rider
And that's the basic you should know to start making your own crawlers :-)
Libraries used
in 2016 things are way easier. install jquery to node.js with your console:
npm install jquery
bind it to the variable $
(for example - i am used to it) in your node.js code:
var $ = require("jquery");
do stuff:
$.ajax({
url: 'gimme_json.php',
dataType: 'json',
method: 'GET',
data: { "now" : true }
});
also works for gulp as it is based on node.js.
I believe the answer to this is now yes.
https://github.com/tmpvar/jsdom
var navigator = { userAgent: "node-js" };
var jQuery = require("./node-jquery").jQueryInit(window, navigator);
jQuery module can be installed using:
npm install jquery
Example:
var $ = require('jquery');
var http = require('http');
var options = {
host: 'jquery.com',
port: 80,
path: '/'
};
var html = '';
http.get(options, function(res) {
res.on('data', function(data) {
// collect the data chunks to the variable named "html"
html += data;
}).on('end', function() {
// the whole of webpage data has been collected. parsing time!
var title = $(html).find('title').text();
console.log(title);
});
});
References of jQuery in Node.js** :
First of all install it
npm install jquery -S
After installing it, you can use it as below
import $ from 'jquery';
window.jQuery = window.$ = $;
$(selector).hide();
You can check out a full tutorial that I wrote here: https://medium.com/fbdevclagos/how-to-use-jquery-on-node-df731bd6abc7
WARNING
This solution, as mentioned by Golo Roden is not correct. It is just a quick fix to help people to have their actual jQuery code running using a Node app structure, but it's not Node philosophy because the jQuery is still running on the client side instead of on the server side. I'm sorry for giving a wrong answer.
You can also render Jade with node and put your jQuery code inside. Here is the code of the jade file:
!!! 5
html(lang="en")
head
title Holamundo!
script(type='text/javascript', src='http://code.jquery.com/jquery-1.9.1.js')
body
h1#headTitle Hello, World
p#content This is an example of Jade.
script
$('#headTitle').click(function() {
$(this).hide();
});
$('#content').click(function() {
$(this).hide();
});
The module jsdom is a great tool. But if you want to evaluate entire pages and do some funky stuff on them server side I suggest running them in their own context:
vm.runInContext
So things like require
/ CommonJS
on site will not blow your Node process itself.
You can find documentation here. Cheers!
As of jsdom v10, .env() function is deprecated. I did it like below after trying a lot of things to require jquery:
var jsdom = require('jsdom');
const { JSDOM } = jsdom;
const { window } = new JSDOM();
const { document } = (new JSDOM('')).window;
global.document = document;
var $ = jQuery = require('jquery')(window);
Hope this helps you or anyone who has been facing these types of issues.
Yes, jQuery
can be used with Node.js
.
Steps to include jQuery in node project:-
npm i jquery --save
Include jquery in codes
import jQuery from 'jquery';
const $ = jQuery;
I do use jquery in node.js projects all the time specifically in the chrome extension's project.
e.g. https://github.com/fxnoob/gesture-control-chrome-extension/blob/master/src/default_plugins/tab.js
No. It's going to be quite a big effort to port a browser environment to node.
Another approach, that I'm currently investigating for unit testing, is to create "Mock" version of jQuery that provides callbacks whenever a selector is called.
This way you could unit test your jQuery plugins without actually having a DOM. You'll still have to test in real browsers to see if your code works in the wild, but if you discover browser specific issues, you can easily "mock" those in your unit tests as well.
I'll push something to github.com/felixge once it's ready to show.
You can use Electron, it allows hybrid browserjs and nodejs.
Before, I tried to use canvas2d in nodejs, but finally I gave up. It's not supported by nodejs default, and too hard to install it (many many ... dependeces). Until I use Electron, I can easily use all my previous browserjs code, even WebGL, and pass the result value(eg. result base64 image data) to nodejs code.
Not that I know of. The DOM is a client side thing (jQuery doesn't parse the HTML, but the DOM).
Here are some current Node.js projects:
https://github.com/ry/node/wiki (https://github.com/nodejs/node)
And SimonW's djangode is pretty damn cool...
An alternative is to use Underscore.js. It should provide what you might have wanted server-side from JQuery.