React

by Lexogram

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

React

class WidthTest extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      phrase: "Hello world"
    , width: 0
    }
    
    this.setWidth = this.setWidth.bind(this)
  }
  
  
  setWidth(element) {
  	console.log(element.getBoundingClientRect())
  }
  
  render() {
    return (
      <div>
        <EditPhrase>
          {this.state.phrase}
        </EditPhrase>
        <WidthHolder
        	setWidth={this.setWidth}
        >
          {this.state.phrase}
        </WidthHolder>
        <Input
        	phrase={this.state.phrase}
        />
      </div>
    )
  }
}


const EditPhrase = () => (
	<textarea>{this.props.phrase}</textarea>
)


class WidthHolder extends React.Component {
	render() {
    <span
    	ref={this.props.setWidth}
    >
      {this.props.children}
    </span>
  }
}

const Input = (props) => (
	<input
    type="text"
    placeholder="props.phrase"
  />
)

ReactDOM.render(
  <WidthTest />
, document.querySelector("#app")
)