gistfile1.txt

// Parent

{namespace Parent}

{template .render}
  {param title: string}

  {param _customEventListener: any}

  {call ChildA.render}
    {param events: [
      'customEvent': $_customEventListener
    ]}
    {param ref: 'childA'}
  {/call}
{/template}

// Parent JS

class Parent extends Component {
  myFunction() {
    console.log(this.refs) // return object containing 'childA'

    this.refs['childA'].functionToCall();
  }


  _customEventListener({someData}) {
    // called when child emits it

    console.log({someData}); // data passed up
  }
}

// ChildA

{namespace ChildA}

{template .render}
  {param title: string}
{/template}

// ChildA JS

class ChildA extends Component {
  myFunction() {
    this.emit('customEvent', {someData});
  }


  _customEventListener() {
    // called when child emits it
  }
}