Render HTML string as real HTML in a React component

Question

Is this.props.match.description a string or an object? If it's a string, it should be converted to HTML just fine. Example:

class App extends React.Component {

constructor() {
    super();
    this.state = {
      description: '<h1 style="color:red;">something</h1>'
    }
  }
  
  render() {
    return (
      <div dangerouslySetInnerHTML={{ __html: this.state.description }} />
    );
  }
}

ReactDOM.render(<App />, document.getElementById('root'));

Result: http://codepen.io/ilanus/pen/QKgoLA?editors=1011

However if description is <h1 style="color:red;">something</h1> without the quotes '', you're going to get:

​Object {
$$typeof: [object Symbol] {},
  _owner: null,
  key: null,
  props: Object {
    children: "something",
    style: "color:red;"
  },
  ref: null,
  type: "h1"
}

If It's a string and you don't see any HTML markup the only problem I see is wrong markup..

UPDATE

If you are dealing with HTML Entities, You need to decode them before sending them to dangerouslySetInnerHTML that's why it's called "dangerously" :)

Working example:

class App extends React.Component {

  constructor() {
    super();
    this.state = {
      description: '<p><strong>Our Opportunity:</strong></p>'
    }
  }

   htmlDecode(input){
    var e = document.createElement('div');
    e.innerHTML = input;
    return e.childNodes.length === 0 ? "" : e.childNodes[0].nodeValue;
  }

  render() {
    return (
      <div dangerouslySetInnerHTML={{ __html: this.htmlDecode(this.state.description) }} />
    );
  }
}

ReactDOM.render(<App />, document.getElementById('root'));

I use 'react-html-parser'

yarn add react-html-parser

import ReactHtmlParser from 'react-html-parser'; 

<div> { ReactHtmlParser (html_string) } </div>

Source on npmjs.com

Lifting up @okram's comment for more visibility:

from its github description: Converts HTML strings directly into React components avoiding the need to use dangerouslySetInnerHTML from npmjs.com A utility for converting HTML strings into React components. Avoids the use of dangerouslySetInnerHTML and converts standard HTML elements, attributes and inline styles into their React equivalents.

Check if the text you're trying to append to the node is not escaped like this:

var prop = {
    match: {
        description: '<h1>Hi there!</h1>'
    }
};

Instead of this:

var prop = {
    match: {
        description: '<h1>Hi there!</h1>'
    }
};

if is escaped you should convert it from your server-side.

The node is text because is escaped

The node is a dom node because isn't escaped

If you have control over where the string containing html is coming from (ie. somewhere in your app), you can benefit from the new <Fragment> API, doing something like:

import React, {Fragment} from 'react'

const stringsSomeWithHtml = {
  testOne: (
    <Fragment>
      Some text <strong>wrapped with strong</strong>
    </Fragment>
  ),
  testTwo: `This is just a plain string, but it'll print fine too`,
}

...

render() {
  return <div>{stringsSomeWithHtml[prop.key]}</div>
}