block1.tsx

import * as React from "react";

interface Props {
    exposing: (self: MyReactComponent) => void;
}

interface State {
    someData: any[];
}

class MyReactComponent extends React.Component<Props, State> {

  constructor(props: Props) {
    super(props);
    this.state = { someData: [] };
  }

  public fetchDataAndUpdate() {
    //fetches some data and updates state
  }

  public render() {
    return <div>...</div>;
  }
}