Created
January 28, 2026 19:06
-
-
Save deanebarker/27d72daa73c71e7f9239ccc92b356e0e to your computer and use it in GitHub Desktop.
A JavaScript function to "sanitize" HTML returning from an HTMX request
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| document.body.addEventListener("htmx:beforeSwap", function (evt) { | |
| const customEvt = evt as CustomEvent; | |
| let rawHtml = customEvt.detail.serverResponse; | |
| rawHtml = sanitizeHtml(rawHtml, "#" + container.id); | |
| customEvt.detail.serverResponse = rawHtml; | |
| }); | |
| function sanitizeHtml(htmlString: string, scopeSelector: string) { | |
| const parser = new DOMParser(); | |
| const doc = parser.parseFromString(htmlString, "text/html"); | |
| // 1. Remove all <script> tags | |
| doc.querySelectorAll("script").forEach((el) => el.remove()); | |
| // 2. Walk all elements once | |
| doc.querySelectorAll("*").forEach((el) => { | |
| // 2a. Remove attributes starting with "on" | |
| [...el.attributes].forEach((attr) => { | |
| if (attr.name.toLowerCase().startsWith("on")) { | |
| el.removeAttribute(attr.name); | |
| } | |
| if (attr.name.toLowerCase().startsWith("hx-on")) { | |
| el.removeAttribute(attr.name); | |
| } | |
| }); | |
| // 2b. Rewrite hx-target | |
| const hxTarget = el.getAttribute("hx-target"); | |
| if (hxTarget) { | |
| const newVal = rewriteHxTarget(hxTarget, scopeSelector); | |
| el.setAttribute("hx-target", newVal); | |
| } | |
| }); | |
| // 3. Scope all <style> blocks | |
| doc.querySelectorAll("style").forEach((el) => { | |
| var style = el.textContent; | |
| el.textContent = `${scopeSelector} { ${style} }`; | |
| }); | |
| return doc.body.innerHTML; | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment