.

这样可以方便的进行单元测试，不需要模拟Api.fetch函数的具体返回结果。

const shopItemsSelector = state => state.shop.items const taxPercentSelector = state => state.shop.taxPercent

const subtotalSelector = createSelector( shopItemsSelector, items => items.reduce((acc, item) => acc + item.value, 0) )

I’ve personally seen two big benefits after adopting this strict separation in production apps. The first is that teams can more easily reuse the Presentation Components because they are nothing more than html/css. Over time this will allow the team to amass a great component library that is more composable allowing even greater code sharing across the organization. The second benefit is that teams can more easily upgrade the infrastructure that powers data flow throughout the application. Because this code is isolated in the Container Components we don’t need to untangle the plumbing code from the html/css that displays it. So you want to swap your global store for an ember service? No problem! We just modify the entry point in the Container Components and the data still flows down to any Presentational Components like it did before the refactor.

Therefore we've built https://github.com/salsita/redux-side-effects which is at least "somehow" trying to simulate the Continuations with Effect handlers approach. The idea is very simple, if reducer was generator then you could simply yield side effects and return mutated app state. So the only condition is to turn all your reducers into function* and use yield* whenever you want to compose them.

All kinds of frameworks and architectures have state. In Ember apps and Backbone apps, state is in Models. In Angular apps, state is often in Factories and Services. In most Flux implementations, it is in Stores. How does Redux differ from these?

You can call store.dispatch(action) from anywhere in your app, including components and XHR callbacks, or even at scheduled intervals.

Now todoApp just gives it the slice of the state to manage, and todos knows how to update just that slice.

If your head boiled from reading the above section, imagine what it was like to write it.