app.model = {
   addItem: function() { .. }
   update: function() { .. }

}

<MyButton model={app.model}>Add Item</MyButton>

var MyButton  = React.createClass({
  render: function() {
    return (
       <div className="coolButton" onClick={this.props.model.addItem}>
           {this.props.children}
       </div>
})

var MyModal  = React.createClass({

   getInitialState: function() {
     return {isShown: false};
   },

  render: function() {
    if (this.state.isShow===false) {
        return
    }
    return (
       <div className="modal">
           {this.props.children}
       </div>
})