Redux is available as a package on NPM for use with a module bundler or in a Node application:

npm install --save redux

Let’s discuss the basic concepts of Redux.

UI loop

So now we will see the overall concept of redux and see hows it works. Here, we can see that we have a UI and when a user performs an action it will change the state of the data.

You may also like:
Angular Tutorial: State Management With NgRx

What Is the State?

All the application data is collectively known as the store and it is to be represented as a state. Also, we cannot change the state as it is immutable. We can change the state only using Action, which itself is an object which included two things:

Type: Type is nothing but it is an Action Name.

Payload: Alternatively, Payload is something we can refer to as Action Data.

Example of Action:

So How’s it works?

1: When data changes, the existing state is duplicated, then a new object is created with the updates. In Angular this data is treated as an RxJS Observable, allowing us to subscribe to it from anywhere in the app.

2: When an event is emitted, for example, a button click, the action is sent to a reducer function to converts the old state into the new state.

{ type: 'DELETE_ITEM', payload: 123 }

Here, you can see that in action, Delete_Item is our action name and 123 is action data.

How to Configure ngRx?

NgRx: The ngRx is an angular version of the redux pattern. Which is inspired by the group of libraries inspired by flux patterns? What do I mean with the “angular/rxjs” version of redux? The angular part is because ngrx is a library to use within an angular application. The rxjs “part is because of the implementation of ngrx works around an rxjs flow.

NgRX

You can set up ngRx with just two steps described below:

1: create one new app with Angular-CLI and give it any name to it.

2: Install the ngrx/store via npm in your system with the following command.

app.module.ts

ngrx.reducer.ts

Now let us understand this concept with the help of the basic example shown below:

Here, in this file, we need to update the app module file with the post reducer, for that we need to import the post reducer.

app.component.ts

Now, we will create one another file in which we create the reducer.

Here we have switch statements with the possible actions and this whole function is collectively known as a reducer. In this function, the switch statement returns the statement as ‘i am learning’ in different languages depending upon the actions.

  • Now if we want to change the state and we will use the class store then we need to implement interface corresponding to the object necessary to pass to the ngModule.
  • A variable for message$ is set as an Observable on the component by calling this.store.select(‘message’).

Thanks for reading!

Now we can subscribe to the Observable in the HTML and trigger changes with button click events.

Conclusion: I hope this blog is useful for you to get the basic understanding of ngrx with redux after reading this blog and you will start using it in your application.

Further Reading

State Management Using NGXS in Angular

Separating State Into Angular Modules With Ngrx

Angular Tutorial: Redux and mat-selection-list



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