javascript - ReactJs: Prevent multiple times button press

Question

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 it's 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 simpler before I started trying everything I could think of
  onClickUploadFile() {
    if (!this.state.showUploadButton) {
      return;
    }
    this.disableUploadButton(function() {
      $.ajax({
        [...]
      });

    });
  },

  render() {
    var uploadButton;
    if (this.state.showUploadButton) {
      uploadButton = (
        <button onClick={this.onClickUploadFile}>Send</button>
      );
    }

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

});

What I think happens is the state variable showUploadButton not being updated right away, which the React docs says is expected.

How could I enforce the button to get disabled or go away all-together the instant it's being clicked?

Answer 1

The solution is to check the state immediately upon entry to the handler. React guarantees that setState?inside interactive events (such as click) is flushed at browser event boundary. Ref: https://github.com/facebook/react/issues/11171#issuecomment-357945371

// In constructor
this.state = {
    disabled : false
};


// Handler for on click
handleClick = (event) => {
    if (this.state.disabled) {
        return;
    }
    this.setState({disabled: true});
    // Send     
}

// In render
<button onClick={this.handleClick} disabled={this.state.disabled} ...>
    {this.state.disabled ? 'Sending...' : 'Send'}
<button>