Comment by biscarch

Loading (and error, etc) state should be the responsibility of the component doing the content rendering, not the parent. So the ConditionalSpinner component:

   <ConditionalSpinner renderIf={data}><PersonRenderer person={data.person} /></ConditionalSpinner>

Could be written better as:

   <PersonRenderer person={data.person} />

Where PersonRenderer would be defined as such:

   class PersonRenderer extends Component {
     render() {
       if(this.props.person) {
         return <div>personcontent</div>
       }
       return <LoadingIndicator/>
     }
   }

Given this, I'm still not sure how an If "component" would be achieved (and further, you'd need an Else or a Switch component anyway if going down this route). Maybe you could explain the benefits of such a path?