ReactJs: Prevent multiple times button press

In my React component I have a button meant to send some data over AJAX when clicked. I need to happen only the first time, i.e. to disable the button after its first use. How I'm trying to do this: var UploadArea = React.createClass({ getInitialState() { return { showUploadButton: true }; }, disableUploadButton(callback) { this.setState({ showUploadButton: false }, callback); }, // This was simpl