Any of those help There were lots of issues in your app. I fixed all of them and the new App component should be like this. Firstly inside the render method you need to call the two child components render methods using the (). Next to the renderContent function you need to pass one content instance at a time, not an array. I have posted the App component with all the changes I made to make it work below.
I wish did fix the issue. You forgot to bind the forEach function and hence the error since, this inside forEach function will refer to its own context where handleClick is not defined rather than the React Component, Either use .bind(this) like