Type and value validators
In this section, we'll look at the more advanced validator functionality available in the React PropTypes facility. First, you'll learn about the element and node validators that check for values that can be rendered inside HTML markup. Then, you'll see how to check for specific types, beyond the primitive type checking you saw in the previous section. Finally, we'll implement validation that looks for specific values.
Things that can be rendered
Sometimes, you just want to make sure that a property value is something that can be rendered by JSX markup. For example, if a property value is an array, this can't be rendered by putting it in {}. You have to map the array items to JSX elements.
This sort of checking is especially useful if your component passes property values to other elements as children. Let's look at an example of what this looks like:
import React, { PropTypes } from 'react';
const MyComponent = ({
myHeader,
myContent, ...