问题
I am new to javascript and Node.js but I am trying to figure out if there is an alternative to document.getElementById() in Node that has the same function. If it cannot be done in Node, is it possible to create a pure js file to manipulate the DOM and a separate Node file. For extra information, what I am trying to do is to convert csv lines into a json object and then update the webpage with new information which is why I want to use document.getElementById().
回答1:
document.getElementById() is a function that exists in a browser. There is no such function in nodejs.
It is possible to get a 3rd party module that will parse an HTML web page, create a DOM and then allow you to access the DOM programmatically to see what's in the web page. Cheerio and Puppeteer are two such 3rd party modules, each with differing levels of features. Puppeteer actually uses the Chromium browser engine and can even run Javascript in the page and generate screenshots. Cheerio parses the HTML and lets you access just what it creates (without Javascript running).
It sounds like maybe you're a bit confused about how web pages work. A browser running on the end user's computer loads a web page. Once the page is loaded, at that point the server's job is done. The web page exists only in the browser on the user's computer. The server can't directly, on its own, change that web page.
To change that web page (without reloading it), you would have to have supporting Javascript code in the web page (that runs in the user's browser). For example, you could have your Javascript make an Ajax call from the web page that would request certain data from the server. When the server gets that request, it could generate the data and return JSON back to the browser. The Javascript in the browser would then receive that JSON, parse it into a Javascript object and then use the DOM to insert new objects into the existing web page based on the data it received.
Note that all changes to the existing web page in the browser are made by the Javascript running in the web page in the user's browser, not directly by the server. The server can supply data, but cannot directly change the user's web page itself. Of course, the user could request an update page and the browser would request a new version of the whole page and the server could then supply a page that had different data in it, but that would involve reloading the whole page.
There are also template engines that exist for nodejs so that when your server is generating a web page, the template engine can help you create a set of HTML for that web page that incorporates dynamic data. This doesn't dynamically change a web page that is already sitting in a browser being displayed. Instead, it helps you generate a web page from scratch that incorporates dynamic data into the web page when it is first downloaded. Examples of templates engines that work with Express in nodejs are Pug, EJS, Nunjucks, handlebars and many others.
来源：https://stackoverflow.com/questions/63405964/how-to-manipulate-dom-using-node-js