There is a pattern that is gaining consensus within the React community, and it is known as FunctionAsChild. It is widely used in the popular library react-motion, which we will see in Chapter 6, Write Code for the Browser.

The main concept is that, instead of passing a child in the form of a component, we define a function that can receive parameters from the parent.

Let's see what it looks like:

  const FunctionAsChild = ({ children }) => children();
   
  FunctionAsChild.propTypes = { 
    children: func.isRequired
  };

As you can see, FunctionAsChild is a component that has a children property defined as a function and, instead of being used as a JSX expression, it gets called.

The preceding component can be used in the following way:

  <FunctionAsChild> 
    {() => <div>Hello, World!</div>} 
  </FunctionAsChild>

It is as simple...