Inserting the iframe into react component

You can use property dangerouslySetInnerHTML, like this

const Component = React.createClass({
  iframe: function () {
    return {
      __html: this.props.iframe
    }
  },

  render: function() {
    return (
      <div>
        <div dangerouslySetInnerHTML={ this.iframe() } />
      </div>
    );
  }
});

const iframe = '<iframe src="https://www.example.com/show?data..." width="540" height="450"></iframe>'; 

ReactDOM.render(
  <Component iframe={iframe} />,
  document.getElementById('container')
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="container"></div>

 Run code snippetExpand snippet

also, you can copy all attributes from the string(based on the question, you get iframe as a string from a server) which contains <iframe> tag and pass it to new <iframe> tag, like that

/**
 * getAttrs
 * returns all attributes from TAG string
 * @return Object
 */
const getAttrs = (iframeTag) => {
  var doc = document.createElement('div');
  doc.innerHTML = iframeTag;

  const iframe = doc.getElementsByTagName('iframe')[0];
  return [].slice
    .call(iframe.attributes)
    .reduce((attrs, element) => {
      attrs[element.name] = element.value;
      return attrs;
    }, {});
}

const Component = React.createClass({
  render: function() {
    return (
      <div>
        <iframe {...getAttrs(this.props.iframe) } />
      </div>
    );
  }
});

const iframe = '<iframe src="https://www.example.com/show?data..." width="540" height="450"></iframe>'; 

ReactDOM.render(
  <Component iframe={iframe} />,
  document.getElementById('container')
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="container"><div>