How to render a HTML comment in React?

Currently the render method can only return a single element/component. See: here

In the discussion under that ticket some suggest to wrap multiple elements returned from a React component in a HTML comment so that the wrapping component is ignored by the browser, eg:

<A>
    <B></B>
    <Fragment>
        <C></C>
        <D></D>
    </Fragment>
    <E></E>
</A>

would render to:

<a>
    <b></b>
    <!--<fragment data-reactid="">-->
        <c></c>
        <d></d>
    <!--</fragment>-->
    <e></e>
</a>

But how to actually create a component that renders just HTML comment? In other words, how the render function of the 'fragment' component in the example above could look like?

---

This is what I have ended up with in one of my recent projects:

import React, {Component, PropTypes} from 'react';
import ReactDOM from 'react-dom';

class ReactComment extends Component {
    static propTypes = {
        text: PropTypes.string,
        trim: PropTypes.bool
    };

    static defaultProps = {
        trim: true
    };

    componentDidMount() {
        let el = ReactDOM.findDOMNode(this);
        ReactDOM.unmountComponentAtNode(el);
        el.outerHTML = this.createComment();
    }

    createComment() {
        let text = this.props.text;

        if (this.props.trim) {
            text = text.trim();
        }

        return `<!-- ${text} -->`;
    }

    render() {
        return <div />;
    }
}

export default ReactComment;

So you can use it like this:

<A>
    <B></B>
    <ReactComment text="<fragment>" />
        <C></C>
        <D></D>
     <ReactComment text="</fragment>" />
    <E></E>
</A>

---

Edit: For those who found this answer useful, checkout this answer instead!

The posted problem is not asking for comment style in React!

---

Use curly brackets, such that you can use javascript comment /* */ .

<a>
    <b></b>
    {/*<fragment data-reactid="">*/}
        <c></c>
        <d></d>
    {/*</fragment>*/}
    <e></e>
</a>

---

The way you are planning to do this won't work with a plain vanilla React solution. However, you can define a custom web component which converts into HTML comments and return that from within a React wrapper. An example component is implemented here. For usage in React, refer to this url.

Update 19/01/2017

So this is untested theory, but the web component can be something like -

```

 /**
 * <react-comment-sentinel> Web Component
 *
 * @usage
 *  <react-comment-sentinel sentinel="fragment"><div>Hello there!</div></react-comment-sentinel>

 * @result
 *  <!-- <fragment> --><div>Hello there!</div><!-- </fragment> -->
 */
var proto = Object.create(HTMLElement.prototype, {
 name: { get: function() { return 'React HTML Comment'; } },
 createdCallback: { value: function() {

  /**
   * Firefox fix, is="null" prevents attachedCallback
   * @link https://github.com/WebReflection/document-register-element/issues/22
   */
  this.is = '';
  this.removeAttribute('is');
 } },
 attachedCallback: { value: function() {
  var tag = this.attributes("sentinel");
  this.outerHTML = '<!-- <' + tag + '> -->' + this.innerHtml + '<!-- </' + tag + '> -->';
 } }
});
document.registerElement('react-comment-sentinel', { prototype: proto });

```

Notice that the inner children are plain html, not React. However, you can experiment with enhancing the code to support React Components too.

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