Redux Redux is a predictable state container for JavaScript apps. As state in application becomes increasingly complicated for SAP, there might be more different types of state to manage: local created data which is not persisted to the server, UI data like UI elements properties, routes, spinners, paginations which determines the UI display; and server returned and cached data, etc. Redux attempts to make state mutations predictable for complicated application state by imposing certain restrictions on how and when updates can happen. These restrictions are reflected in the three principles of Redux. Three principles of Redux Single source of truth for application state: The global state of application is stored in an object tree within a single store; State is read-only: The state cannot be modified directly by views or network callbacks, the right way to mutate is to dispatch an action to notify the reducer to process. As all changes are centralised and happen one by one in a strict order, there are no subtle race conditions to watch out for; Changes are made with pure functions: Change state via reducers. A reducer is a pure function with two characteristics: It returns same result when the input parameters are the same; the only dependency of the returned data are the input parameters, and the result is consistent regardless of where/when it is called. no side-effects: the function will not do jobs like: modify external data, render DOM elements, execute network requests, IO operations. These characteristics provides assurance to make state predictable. Three core concepts of Redux Actions: an action…

2020年09月05日 0Comments 731Browse 1Like Read more