React: Checkbox behavior inexplicable when preventDefault() is used

[tigergrid]

var React = require('react'),
    Backbone = require('backbone'),
    Flux = require('flux'),
    dispatcher = new Flux.Dispatcher();

var storeListeningMixin = {
  componentDidMount: function () {
    if (this.props.store && this.onStoreChanged) {
      this.props.store.on('change:emit', this.onStoreChanged, this);
    }
  },
  componentWillUnmount: function () {
    if (this.props.store && this.onStoreChanged) {
      this.props.store.off('change:emit', this.onStoreChanged);
    }
  }
};

var dispatchingMixin = {
  componentWillMount: function () {
    this.dispatch = function (payload) {
      dispatcher.dispatch(payload);
    };
  }
};

function register(store) {
  store.dispatcher = dispatcher;
  store.dispatchId = dispatcher.register(store.onDispatch.bind(store));
}

function unregister(store) {
  delete store.dispatcher;
  dispatcher.unregister(store.dispatchId);
}


var Store = Backbone.Model.extend({
  checked: [false, false],
  onDispatch: function (payload) {
    if (payload.actionType === 'ha') {
      console.log('dispatch received for checkbox' + payload.ind + '.');
      this.checked[payload.ind] = !this.checked[payload.ind];
      this.trigger('change:emit');
    }
  }
});

var store = new Store();

var Checkboxa = React.createClass({
    mixins: [dispatchingMixin],
    onChange: function(e) {
      console.log('dispatching...');
      e.preventDefault();  // This makes the checkbox behave weirdly - if removed things are normal
      this.dispatch({actionType: 'ha', ind: this.props.ind});
    },
    render: function() {
      var checked = this.props.store.checked[this.props.ind];
      console.log('checkbox rendering, should be checked: ' + checked);
      return (
        <li><input type="checkbox" checked={checked} key={this.props.ind}
             onChange={this.onChange}/><span>{this.props.ind}</span></li>
      );
    }
});

var CheckboxaList = React.createClass({
  mixins: [storeListeningMixin],
  onStoreChanged: function() {
    this.forceUpdate();
  },
  render: function() {
    return (
      <ul>
        <Checkboxa ind={0} key={0} store={this.props.store} />
        <Checkboxa ind={1} key={1} store={this.props.store} />
      </ul>
    );
  }
});

register(store);

React.render(
  <CheckboxaList store={store}/>,
  document.getElementById('renderArea')
);

Notice how clicking the checkbox does not make React render it according to the checked state, but clicking the other checkbox causes the checkbox to re-render correctly.
In theory the preventDefault() happened when the component was dispatching and shouldn't affect the rendering? In any case the component shouldn't be rendered incorrectly?

[jquense]

this is because under the hood react listens for Click events instead of Change to normalize browser differences. The accepted solution is: don't use preventDefault (use stopPropagation instead) or make use of a timeout. more reading here https://github.com/facebook/react/issues/3005

[tigergrid]

@jquense Can you maybe detail exactly what is going on? The effect is still observed when you use onClick directly. Can you maybe give me a flow of how this is happening?

[jquense]

@tigergrid you can read the issue I linked, zpao covers it quite nicely. https://github.com/facebook/react/issues/3005#issuecomment-72513965

essentially you are running into a limitation of how react implements the onChange event for checkboxes

[zpao]

This is unfortunate but the way it is for now. If you don't have a good reason for using preventDefault(), don't.