Render HTML string as real HTML in a React component

Question

Here's what I tried and how it goes wrong.

This works:

<div dangerouslySetInnerHTML={{ __html: "<h1>Hi there!</h1>" }} />

This doesn't:

<div dangerouslySetInnerHTML={{ __html: this.props.match.description }} />

---

The description property is just a normal string of HTML content. However it's rendered as a string, not as HTML for some reason.

Any suggestions?

Answer 1

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'));