2.4 Redux Core Concept

Redux itself is very simple. The state of the app we created in the last article can be represented as a generic object like this:

This object is the same as the model without setters.

To change this state in Redux, you must dispatch an action.

Actions are plain objects describing what happened in the app, and serve as the sole way to describe an intention to mutate the data. It’s one of the fundamental design choices of Redux.

Here are some examples to be implemented in our app soon.

Forcing all of these state changes into action will give us a clear understanding of what’s going on in your app. When something happens, we can see why it happened.

Now we need a function called reducer to bind these states and actions together. Reducer is nothing more than a function that takes a state and an action as arguments and returns a new state.

In a word:

(state, action) => state

Actions only describe that something happened and don’t specify how the application’s state changes in response. This is the job of reducers.

Here is one example of a reducer to implement in our app: