how to wrap javascript string with tag in another tag by regex?

Question

I have string with link

<a href="https://twitter.com/" target="_blank" rel="noopener noreferrer">Twitter/</a>

and I need to wrap a text inside link in a <span> element

like :

<a href="https://twitter.com/" target="_blank" rel="noopener noreferrer"><span style="color: white">Twitter</span>/</a>

so what regex i need ? ps. i need to send this string as part of html mail letter from mongodb via nodejs, not for manipulate DOM

Why don't you make use of the DOM for this or a parser instead of a regex? — The fourth bird, Dec 13 '22 at 17:43
it's not about layout or dom, it's about sending this string from mongodb via nodejs in html letter — Mithra, Dec 13 '22 at 17:50
If it is via nodejs, I think you can use a [DOMParser with node js](https://stackoverflow.com/questions/11398419/trying-to-use-the-domparser-with-node-js) — The fourth bird, Dec 13 '22 at 17:51
You can use DOM methods, then get the `outerHTML` to convert it to a string for sending email. — Barmar, Dec 13 '22 at 18:11

score 1 · Answer 1 · answered Dec 13 '22 at 19:05

It's safest to use a DOMParser with node.js as "The fourth bird" mentioned: Trying to use the DOMParser with node js

You can use a regex, which might not cover all corner cases. Here are two options:

const input = '<a href="https://twitter.com/" target="_blank" rel="noopener noreferrer">Twitter/</a>';

let regex1 = /(<a [^>]*>)(.*?)(<\/a>)/gi;
let result1 = input.replace(regex1, '$1<span style="color: white">$2</span>$3');
console.log('result1:', result1);

let regex2 = /(?<=<a [^>]*>)(.*?)(?=<\/a>)/gi;
let result2 = input.replace(regex2, '<span style="color: white">$1</span>');
console.log('result2:', result2);

Output:

result1: <a href="https://twitter.com/" target="_blank" rel="noopener noreferrer"><span style="color: white">Twitter/</span></a>
result2: <a href="https://twitter.com/" target="_blank" rel="noopener noreferrer"><span style="color: white">Twitter/</span></a>

Explanation of regex1:

(<a [^>]*>) -- capture group 1: anchor tag
(.*?) -- capture group 2: non-greedy scan
(<\/a>) -- capture group 3: anchor end tag
in replacement part use captured groups $1, $2, $3

Explanation of regex2:

similar to regex1, but using a positive lookbehind instead of capture group 1, and a positive lookahead instead of capture group 2 (this is not supported by all JavaScript engines)

Ronnie Royston · Answer 2 · 2022-12-13T19:13:06.890

0

Using jsdom

var anchor = document.querySelector("a");
var anchorText = anchor.textContent;

anchor.innerText = "";
var span = document.createElement("span");
var spanText = document.createTextNode(anchorText);
span.appendChild(spanText)
anchor.appendChild(span);

console.log(anchor.innerHTML);

<a href="https://twitter.com/" target="_blank" rel="noopener noreferrer">Twitter/</a>

edited Dec 13 '22 at 19:13

answered Dec 13 '22 at 17:52

Ronnie Royston

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The OP states node.js, not browser environment – Peter Thoeny Dec 13 '22 at 19:08

score 0 · Answer 3 · answered Dec 16 '22 at 09:40

We can also achieve this requirement by simply using String.replace() method.

Live Demo :

var anchor = document.querySelector("a");
var anchorText = anchor.textContent;

anchor.innerHTML = anchorText.replace(anchorText, `<span style="color: red">${anchorText}</span>`)

<a href="https://twitter.com/" target="_blank" rel="noopener noreferrer">Twitter/</a>

how to wrap javascript string with tag in another tag by regex?

3 Answers3