title: How to use Material-ui@next TextField error props
body: <p>I want to use Material-UI Next textfield <code>error</code> props <a href="https://material-ui-next.com/api/text-field/#textfield" rel="noreferrer">link</a>, the props type is <code>boolean</code>. The previous version of Material-UI props name is <code>errorText</code> and the props type is <code>node</code> <a href="http://www.material-ui.com/#/components/text-field" rel="noreferrer">link</a>.</p>
  
  <p>Textfield Material-UI previous version using <code>errorText</code> props :</p>
  
  <pre><code>&lt;TextField
    name='name'
    floatingLabelText='Name'
    hintText='Type your name'
    value={this.state.fields.name}
    onChange={this.onChange}
    errorText={this.state.error}
  /&gt;
  </code></pre>
  
  <p>With <code>errorText</code> in Material-UI previous version, the code works good for displaying an error state.</p>
  
  <p>Textfield Material-UI Next using <code>error</code> props:</p>
  
  <pre><code>&lt;TextField
    name='name'
    label='Name'
    placeholder='Type your name'
    value={this.state.fields.name}
    onChange={this.onChange}
    error={true} //only accept true or false value
  /&gt;
  </code></pre>
  
  <p>On Material-UI Next <code>errorText</code> props changed to <code>error</code> with boolean type and only accept true or false value. If i set the <code>error</code> props to true, the textfield displaying error state at any time. I just want to displaying error state under certain conditions. </p>
  
  <p>How can i use error state <code>this.state.error</code> on Material-UI Next textfield?</p>