I’m really talking about Flux here more than React. One one of Flux’s strengths is that everything is state driven from a central state ontop of all other components. When any sub-component wants to change data, it produces events that tell the central component to update that centralized state. When the central state is updated, it flows down again to all children. It’s nice because the application can be thought of as a representation of the centralized state.

But it’s also a weakness because ALL mutations have to go through the central component (or data store). You can’t one child component make a change and all other child components notice it directly. This makes the central state code rather large as it has to coordinate all state changes.

We actually use CanJS’s observables with React to avoid this problem. It makes subcomponents a little more self contained and reduces the size of the meatball.