Using Document Object in Nodejs

Node.js define document object

Yes, there are ways to create documents in Node. For example you can look at jsdom: https://github.com/tmpvar/jsdom.

Using Document object in nodejs

script.js is a script designed to run in a browser, not in node.js. It is designed to operate on the current web page and uses the document object to get access to that page.

A node.js execution environment is not the same as a browser. For example, there is no notion of the "current page" like there is in a browser and thus there is no global document or window object either like there is in a browser.

So, this all explains why trying to run node script.js doesn't work. There's no global document object so your script quickly generates an error and exits.

We can't really tell from your question if you just don't really understand the difference between running scripts in a browser vs. running scripts in a node.js environment and that's all you need to have explained or if you actually want to operate on an HTML document from within node.js?

It is possible to operate on HTML pages from within node.js. The usual way to do that is to get an HTML parsing library like jsdom. You can then load some HTML page using that library and it will create a simulated browser DOM and will make things like the document object available to you so you could execute a browser-like script on an HTML document.

How can I access DOM Elements using Node JS?

The error above is very explicit:

document is not defined

document is not exist in Node (e.g. server) environment, it's exist only in browser.

You will need to use separate library to parse your HTML file in order to do queries like querySelector('.container') and etc.

Libraries to take a look (as an example):

https://github.com/taoqf/node-fast-html-parser

https://github.com/cheeriojs/cheerio

Why doesn't Node.js have a native DOM?

The DOM is the DOM, and the JavaScript implementation is simply a separate entity. The DOM represents a set of facilities that a web browser exposes to the JavaScript environment. There's no requirement however that any particular JavaScript runtime will have any facilities exposed via the global object.

What Node.js is is a stand-alone JavaScript environment completely independent of a web browser. There's no intrinsic link between web browsers and JavaScript; the DOM is not part of the JavaScript language or specification or anything.

I use the old Rhino Java-based JavaScript implementation in my Java-based web server. That environment also has nothing at all to do with any DOM. It's my own application that's responsible for populating the global object with facilities to do what I need it to be able to do, and it's not a DOM.

Note that there are projects like jsdom if you want a virtual DOM in your Node project. Because of its very nature as a server-side platform, a DOM is a facility that Node can do without and still make perfect sense for a wide variety of server applications. That's not to say that a DOM might not be useful to some people, but it's just not in the same category of services as things like process control, I/O, networking, database interop, and so on.

There may be some "official" answer to the question "why?" out there, but it's basically just the business of those who maintain Node (the Node Foundation now). If some intrepid developer out there decides that Node should ship by default with a set of modules to support a virtual DOM, and successfully works and works and makes that happen, then Node will have a DOM.

Node.js document is not defined

document relates to the DOM (Document Object Model) in a web browser.

Node.js, however, is not a browser environment. It is a server environment, much like PHP or Perl, and as such, you can’t access the browser’s DOM or do anything specific to browser-hosted JavaScript.

The closest you could get is using something like browserify to include Node.js modules in your client-side code.

Get key from the document object in mongodb using node

Add {_id :0} after query object in find function to remove _id from the result. doc is an array you can't access value directly either you have to use loop or doc[0].userId.

That.find({
    $and: [{
        "userId": {
            "$ne": ""
        }
    }, {
        "userId": {
            "$exists": true
        }
    }]
}, {
    _id: 0
}).sort({
    "_id": -1
}).limit(1).select("userId")

Using Document Object in Nodejs

Node.js define document object