reactjs - How to safely render html in react?

Question

I've got some user generated html markup from a text area and I'd like to render it on another part of the screen. The markup is saved as a string in the props of the component.

I don't want to use dangerouslysethtml for obvious reasons. Is there a parser such as marked but for html so that it strips out script tags and other invalid html.

Answer 1

Sanitize the html using the sanitize-html module, and render the sanitized string using dangerouslySetInnerHTML.

You can create a simple wrapper component:

const defaultOptions = {
  allowedTags: [ 'b', 'i', 'em', 'strong', 'a' ],
  allowedAttributes: {
    'a': [ 'href' ]
  },
  allowedIframeHostnames: ['www.youtube.com']
};

const sanitize = (dirty, options) => ({
  __html: sanitizeHtml(
    dirty, 
    options: { ...defaultOptions, ...options }
  )
});

const SanitizeHTML = ({ html, options }) => (
  <div dangerouslySetInnerHTML={sanitize(html, options)} />
);

Usage:

<SanitizeHTML html="<img src=x onerror=alert('img') />" />

---

You can also use react-sanitized-html's SanitizedHTML component, which is a react wrapper around sanitize-html:

<SanitizedHTML
  allowedAttributes={{ 'a': ['href'] }}
  allowedTags={['a']}
  html={ `<a href="http://bing.com/">Bing</a>` }
/>