将 HTML/DOM 与 node.js 连接

Question

I'm trying to find a way to write to a text file using node.js but I was trying to get the input from the HTML DOM. How do you write the output from the DOM to a text file using fs.writeFile?

Here's some code that doesn't work but thought it might be relevant. Thanks

<h3>A demonstration of how to access a Text Field</h3>

<input id="myText">

<button onclick="myFunction()">Try it</button>

<script>

const fs = require('fs')

function myFunction() {
  var content = document.getElementById("myText").value;
}

fs.writeFile('./test.txt', content, err => {
    if(err){
        console.log(err);
        return
    }
})

</script>

Answer 1

You cannot write file directly from a browser to local computers.
That would be a massive security concern.
*You also cannot use fs on client-side browser

Instead you get inputs from a browser, and send it to your server (NodeJs), and use fs.writeFile() on server-side, which is allowed.

What you could do is:

1. Create a link and prompt to download.
2. Send to server and response with a download.
3. Use native environment like Electron to able NodeJs locally to write into local computer.

What I assume you want to do is 1
Is that case you could simply do:

function writeAndDownload(str, filename){
    let yourContent = str
    //Convert your string into ObjectURL
    let bom = new Uint8Array([0xef, 0xbb, 0xbf]); 
    let blob = new Blob([bom, yourContent], { type: "text/plain" });
    let url = (window.URL || window.webkitURL).createObjectURL(blob);
    //Create a link and assign the ObjectURL
    let link = document.createElement("a");
    link.style.display = "none";
    link.setAttribute("href", url);
    link.setAttribute("download", filename);
    //Automatically prompt to download
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

writeAndDownload("Text you want to save", "savedData")