What is the most convenient way to convert HTML to plain text while preserving line breaks (with JavaScript)?

问题

Basically I just need the effect of copying that HTML from browser window and pasting it in a textarea element.

For example I want this:

<p>Some</p>
<div>text<br />Some</div>
<div>text</div>

to become this:

Some
text
Some
text

回答1:

If that HTML is visible within your web page, you could do it with the user selection (or just a TextRange in IE). This does preserve line breaks, if not necessarily leading and trailing white space.

UPDATE 10 December 2012

However, the toString() method of Selection objects is not yet standardized and works inconsistently between browsers, so this approach is based on shaky ground and I don't recommend using it now. I would delete this answer if it weren't accepted.

Demo: http://jsfiddle.net/wv49v/

Code:

function getInnerText(el) {
    var sel, range, innerText = "";
    if (typeof document.selection != "undefined" && typeof document.body.createTextRange != "undefined") {
        range = document.body.createTextRange();
        range.moveToElementText(el);
        innerText = range.text;
    } else if (typeof window.getSelection != "undefined" && typeof document.createRange != "undefined") {
        sel = window.getSelection();
        sel.selectAllChildren(el);
        innerText = "" + sel;
        sel.removeAllRanges();
    }
    return innerText;
}

回答2:

I tried to find some code I wrote for this a while back that I used. It worked nicely. Let me outline what it did, and hopefully you could duplicate its behavior.

Replace images with alt or title text.
Replace links with "text[link]"
Replace things that generally produce vertical white space. h1-h6, div, p, br, hr, etc. (I know, I know. These could actually be inline elements, but it works out well.)
Strip out the rest of the tags and replace with an empty string.

You could even expand this more to format things like ordered and unordered lists. It really just depends on how far you'll want to go.

EDIT

Found the code!

public static string Convert(string template)
{
    template = Regex.Replace(template, "<img .*?alt=[\"']?([^\"']*)[\"']?.*?/?>", "$1"); /* Use image alt text. */
    template = Regex.Replace(template, "<a .*?href=[\"']?([^\"']*)[\"']?.*?>(.*)</a>", "$2 [$1]"); /* Convert links to something useful */
    template = Regex.Replace(template, "<(/p|/div|/h\\d|br)\\w?/?>", "\n"); /* Let's try to keep vertical whitespace intact. */
    template = Regex.Replace(template, "<[A-Za-z/][^<>]*>", ""); /* Remove the rest of the tags. */

    return template;
}

回答3:

I made a function based on this answer: https://stackoverflow.com/a/42254787/3626940

function htmlToText(html){
    //remove code brakes and tabs
    html = html.replace(/\n/g, "");
    html = html.replace(/\t/g, "");

    //keep html brakes and tabs
    html = html.replace(/<\/td>/g, "\t");
    html = html.replace(/<\/table>/g, "\n");
    html = html.replace(/<\/tr>/g, "\n");
    html = html.replace(/<\/p>/g, "\n");
    html = html.replace(/<\/div>/g, "\n");
    html = html.replace(/<\/h>/g, "\n");
    html = html.replace(/<br>/g, "\n"); html = html.replace(/<br( )*\/>/g, "\n");

    //parse html into text
    var dom = (new DOMParser()).parseFromString('<!doctype html><body>' + html, 'text/html');
    return dom.body.textContent;
}

回答4:

Based on chrmcpn answer, I had to convert a basic HTML email template into a plain text version as part of a build script in node.js. I had to use JSDOM to make it work, but here's my code:

const htmlToText = (html) => {
    html = html.replace(/\n/g, "");
    html = html.replace(/\t/g, "");

    html = html.replace(/<\/p>/g, "\n\n");
    html = html.replace(/<\/h1>/g, "\n\n");
    html = html.replace(/<br>/g, "\n");
    html = html.replace(/<br( )*\/>/g, "\n");

    const dom = new JSDOM(html);
    let text = dom.window.document.body.textContent;

    text = text.replace(/  /g, "");
    text = text.replace(/\n /g, "\n");
    text = text.trim();
    return text;
}

回答5:

Three steps.

First get the html as a string.
Second, replace all <BR /> and <BR> with \r\n.
Third, use the regular expression "<(.|\n)*?>" to replace all markup with "".

来源：https://stackoverflow.com/questions/3813167/what-is-the-most-convenient-way-to-convert-html-to-plain-text-while-preserving-l

标签

javascript

html

plaintext