redux-synapse is a library that is heavily inspired by react-redux and acts as an alternative for the binding of react components to the store in a more explicit manner. The primary difference is the nature in which each component must declare explicity what updates should affect the component via its higher order component; a synapse. With synapse's there is potential to achieve a higher level of performance than a vanillar react-redux setup.
A synapse is declared to listen to specific messages and act upon them. This is an early release of something that I intend to grow over time and build upon to make more efficient.
Install redux-synapse using npm withte following command.
npm install --save redux-synapse
react is a fantastic tool, however with larger trees you end up with an inefficient number of rerenders unless you are very strict with your shouldComponentUpdates, especially over frequently updated state in a standard flux model, or your own store implementation via context. As we know, react-redux utilises the connect higher order component to theoretically make your tree flat, so that updates are dished out directly from the store, and additional rerenders are only done if the state that we are interested in, handled via a mapStateToProps function, changes. This is fantastic as rerenders are expensive, and cutting them out can really solve a large number of performance problems. However in applications that are updating state frequently, such as a video based applcation, or a stock market tracker, you are going to lose performance before the rerenders even happens.
In react performance would go down just based on the fact that all those components are rerendering so frequently.
In a vanilla react-redux although we shortcut the rerenders, we are still going to visit our mapStateToProps of most of our components, and in essence create a new object every single time to be returned and then evaluated upon. This is fine for smaller applications but in an application with 10's or 100's of components this is going to lead to performance problems.
This is where redux-synapse comes in. Using a similar syntactical solution to react-redux, a user can define what paths they are interested in on the state updates, and behind the scenes they are added as subscribers to those keys. If no paths are specified then it will just subscribe to the store like it would in react-redux, otherwise our observer behind the scenes will subscribe to updates to the store via our reducers and then using the paths that are specified as being updated in the reducer, will alert all necessary higher order components and trigger them to begin their own rerender cycle as opposed to visiting all components to then determine which ones should or shouldn't be updated.