Justen  Hintz

Justen Hintz

1566455570

Understanding of ngRx with Redux in Angular

In this post, we will see the basic pattern of Redux and some benefits and some high-level concepts of redux and then we will discuss the brief about ngRx and its basic implementation.

Redux: Redux is a predictable state container for JavaScript apps. It helps you write applications that behave consistently, run in different environments (client, server, and native), and are easy to test. On top of that, it provides a great developer experience, such as live code editing combined with a time-traveling debugger.

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

npm install --save redux

So let’s discuss the basic concepts of redux which are also used for Redux.


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.

Here the question arrives, What is the state?

Basically, 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:

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

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

Example of Action:

{ type: ‘DELETE_ITEM’, payload: 123 }

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

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.

NgRx: The ngRx is an angular version of the redux pattern. Which is inspired by the group of libraries inspired by flux pattern. what do I mean with “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.

How to configure ngRx?

You can set up ngRx with just 2 steps described below:

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

ng new ngrxProject --routing
cd ngrxProject

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

sudo npm install @ngrx/core @ngrx/store --save

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

app.module.ts

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.

import { StoreModule } from '@ngrx/store';
import { simpleReducer } from './simple.reducer';

@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
AppRoutingModule,
StoreModule.forRoot({ message: simpleReducer })
],
bootstrap: [AppComponent]
})
export class AppModule { }

ngrx.reducer.ts

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

import { Action } from ‘@ngrx/store’;

export function simpleReducer(statement: string = ‘I am learning’,
action: Action) {

switch (action.type) {

	case 'German':
	  return statement = 'Ich lerne'

           case 'FRENCH':
             return statement = 'j'apprends'

	default:
	return statement;      
}

}

So, 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.

app.component.ts

  • So 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’).
  • We trigger state changes by sending actions to the reducer with this.store.dispatch (‘ACTION’).
import { Component } from ‘@angular/core’;

import { Store } from ‘@ngrx/store’;
import { Observable } from ‘rxjs/Observable’;

interface AppState {
message: string;
}

@Component({
selector: ‘app-root’,
templateUrl: ‘./app.component.html’,
styleUrls: [‘./app.component.scss’]
})
export class AppComponent {

message$: Observable<string>

constructor(private store: Store) {
this.message$ = this.store.select(‘message’)
}

germanMessage() {
this.store.dispatch({type: ‘GERMAN’})
}

frenchMessage() {
this.store.dispatch({type: ‘FRENCH’})
}
}

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

<h2>{{ message$ | async }}</h2>

<button (click)=“GermanMessage()”>German</button>
<button (click)=“frenchMessage()”>French</button>

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.

Thanks for reading

If you liked this post, share it with all of your programming buddies!

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Further reading about Angular

Angular 8 (formerly Angular 2) - The Complete Guide

Angular & NodeJS - The MEAN Stack Guide

The Complete Node.js Developer Course (3rd Edition)

The Web Developer Bootcamp

Best 50 Angular Interview Questions for Frontend Developers in 2019

How to build a CRUD Web App with Angular 8.0

React vs Angular: An In-depth Comparison

React vs Angular vs Vue.js by Example

Microfrontends — Connecting JavaScript frameworks together (React, Angular, Vue etc)

Building CRUD Mobile App using Ionic 4, Angular 8


#angular #regex #redux #web-development

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Understanding of ngRx with Redux in Angular
Clara  Gutmann

Clara Gutmann

1599666060

Angular NgRx Store | Angular 9 NgRx Example

Angular NgRx Store is a client-side data management pattern used in large applications. The Ngrx/Store implements the Redux pattern using RxJS observables of Angular. The ngrx/store builds on the concepts made famous by Redux and supercharges it with the backing of **RxJS. **

Angular NgRx Store Example

In this blog post, you will learn what Redux pattern, where the pattern can prove to be useful is, and how the design can be used to build better Angular applications.

Angular Ngrx is a group of Angular libraries for reactive extensions. To understand the NgRX concept, you must make a quick dive into the core Redux concepts and Reactive Programming concepts.

#angular #angular ngrx #rxjs #ngrx/store #redux

Christa  Stehr

Christa Stehr

1598940617

Install Angular - Angular Environment Setup Process

Angular is a TypeScript based framework that works in synchronization with HTML, CSS, and JavaScript. To work with angular, domain knowledge of these 3 is required.

  1. Installing Node.js and npm
  2. Installing Angular CLI
  3. Creating workspace
  4. Deploying your First App

In this article, you will get to know about the Angular Environment setup process. After reading this article, you will be able to install, setup, create, and launch your own application in Angular. So let’s start!!!

Angular environment setup

Install Angular in Easy Steps

For Installing Angular on your Machine, there are 2 prerequisites:

  • Node.js
  • npm Package Manager
Node.js

First you need to have Node.js installed as Angular require current, active LTS or maintenance LTS version of Node.js

Download and Install Node.js version suitable for your machine’s operating system.

Npm Package Manager

Angular, Angular CLI and Angular applications are dependent on npm packages. By installing Node.js, you have automatically installed the npm Package manager which will be the base for installing angular in your system. To check the presence of npm client and Angular version check of npm client, run this command:

  1. npm -v

Installing Angular CLI

  • Open Terminal/Command Prompt
  • To install Angular CLI, run the below command:
  1. npm install -g @angular/cli

installing angular CLI

· After executing the command, Angular CLI will get installed within some time. You can check it using the following command

  1. ng --version

Workspace Creation

Now as your Angular CLI is installed, you need to create a workspace to work upon your application. Methods for it are:

  • Using CLI
  • Using Visual Studio Code
1. Using CLI

To create a workspace:

  • Navigate to the desired directory where you want to create your workspace using cd command in the Terminal/Command prompt
  • Then in the directory write this command on your terminal and provide the name of the app which you want to create. In my case I have mentioned DataFlair:
  1. Ng new YourAppName

create angular workspace

  • After running this command, it will prompt you to select from various options about the CSS and other functionalities.

angular CSS options

  • To leave everything to default, simply press the Enter or the Return key.

angular setup

#angular tutorials #angular cli install #angular environment setup #angular version check #download angular #install angular #install angular cli

Curso Angular NgRX - Arquitectura: Effects

Video largo pero necesario sobre Effects en #NgRx y #Angular. Para facilitar su aprendizaje, les dejamos el “índice” de contenidos de este video, asi pueden saltear partes rápidamente:

Introducción: 0:00
Preparación del Service: 4:15
Preparación del Action: 7:20
Preparación del Reducer: 9:30
Preparación del Effects: 13:36
Preparación del Selector: 22:50
Preparación del Index.ts: 23:38
Montaje de todo en el Module y Component: 24:36

#ngrx #angular #what is angular #what is ngrx

Roberta  Ward

Roberta Ward

1593184320

Basics of Angular: Part-1

What is Angular? What it does? How we implement it in a project? So, here are some basics of angular to let you learn more about angular.

Angular is a Typescript-based open-source front-end web application platform. The Angular Team at Google and a community of individuals and corporations lead it. Angular lets you extend HTML’s syntax to express your apps’ components clearly. The angular resolves challenges while developing a single page and cross-platform applications. So, here the meaning of the single-page applications in angular is that the index.html file serves the app. And, the index.html file links other files to it.

We build angular applications with basic concepts which are NgModules. It provides a compilation context for components. At the beginning of an angular project, the command-line interface provides a built-in component which is the root component. But, NgModule can add a number of additional components. These can be created through a template or loaded from a router. This is what a compilation context about.

What is a Component in Angular?

Components are key features in Angular. It controls a patch of the screen called a view. A couple of components that we create on our own helps to build a whole application. In the end, the root component or the app component holds our entire application. The component has its business logic that it does to support the view inside the class. The class interacts with the view through an API of properties and methods. All the components added by us in the application are not linked to the index.html. But, they link to the app.component.html through the selectors. A component can be a component and not only a typescript class by adding a decorator @Component. Then, for further access, a class can import it. The decorator contains some metadata like selector, template, and style. Here’s an example of how a component decorator looks like:

@Component({
    selector: 'app-root',
    templateUrl: 'app.component.html',
    styleUrls: ['app.component.scss']
})

Role of App Module

Modules are the package of functionalities of our app. It gives Angular the information about which features does my app has and what feature it uses. It is an empty Typescript class, but we transform it by adding a decorator @NgModule. So, we have four properties that we set up on the object pass to @NgModule. The four properties are declarations, imports, providers, and bootstrap. All the built-in new components add up to the declarations array in @NgModule.

@NgModule({
declarations: [
  AppComponent,
],
imports: [
  BrowserModule,
  HttpClientModule,
  AppRoutingModule,
  FormsModule
],
bootstrap: [AppComponent]
})

What is Data Binding?

Data Binding is the communication between the Typescript code of the component and the template. So, we have different kinds of data binding given below:

  • When there is a requirement to output data from our Typescript code in the HTML template. String interpolation handles this purpose like {{data}} in HTML file. Property Binding is also used for this purpose like [property] = “data”.
  • When we want to trigger any event like clicking a button. Event Binding works while we react to user events like (event) = “expression”.
  • When we can react to user events and output something at the same time. Two-way Binding is used like [(ngModel)] = “data”.

image for understanding data binding

#angular #javascript #tech blogs #user interface (ui) #angular #angular fundamentals #angular tutorial #basics of angular

Roberta  Ward

Roberta Ward

1595333359

Tutorial: Nx-style monorepo workspace with Angular CLI: Part 5

In the final part of this tutorial, we create the seatmap data access, seat listing feature, shared buttons UI, and shared formatting utilities library. Finally, we compare our approach with the full Nx toolchain.

This tutorial is part of the Angular Architectural Patterns series.

In Part 4 of this tutorial, we used our generate project tool to create the check-in data access library, the check-in feature shell library, the check-in desktop application, and the mobile check-in application. We hooked everything up and reviewed how much was automated by our tool.

In this part of the tutorial, we’re going to create the seatmap data access library with NgRx feature state. We then created the seat listing feature library and hooked it up to all applications with routing. Finally, we created the shared buttons UI library and the shared formatting utilities library which we used in the seat listing component.

THIS AD MAKES CONTENT FREE. HIDE

Seatmap data access library#

The shared seatmap feature has its own data access library. This is where we would add data services and application state management specific to the seatmap domain.

npm run generate-project -- library data-access --scope=seatmap --grouping-folder=shared/seatmap --npm-scope=nrwl-airlines --with-state
# or
yarn generate-project library data-access --scope=seatmap --grouping-folder=shared/seatmap --npm-scope=nrwl-airlines --with-state
<>

Generate the seatmap data access library.

For now, we’ll put the feature store and effects in place by using the --with-stateparameter of the generate project tool. Note that we use the nested grouping folder shared/seatmap.

// seatmap-data-access.module.ts
import { NgModule } from '@angular/core';
import { EffectsModule } from '@ngrx/effects';
import { StoreModule } from '@ngrx/store';

import { SeatmapEffects } from './+state/seatmap.effects';
import * as fromSeatmap from './+state/seatmap.reducer';

@NgModule({
  imports: [
    StoreModule.forFeature(fromSeatmap.seatmapFeatureKey, fromSeatmap.reducer),
    EffectsModule.forFeature([SeatmapEffects]),
  ],
})
export class SeatmapDataAccessModule {}
<>

The seatmap data access module.

The seatmap data access Angular module gives us an overview of what’s configured in the seatmap data access library. This is a good starting point.

ng run seatmap-data-access:lint

ng run seatmap-data-access:test --watch=false
<>

Lint and test the seatmap data access library.

Everything looks ready to go!

Seat listing feature library#

It’s time to add the first feature of the seatmap domain which is used in both the check-in and booking applications.

npm run generate-project -- library feature feature-seat-listing --scope=seatmap --grouping-folder=shared/seatmap --npm-scope=nrwl-airlines
# or
yarn generate-project library feature feature-seat-listing --scope=seatmap --grouping-folder=shared/seatmap --npm-scope=nrwl-airlines
<>

Generate the seatmap seat listing feature library.

Our tool generates an Angular module and a component for us.

To add this feature to our applications, we add a route to each feature shell module.

// check-in-feature-shell.module.ts
import { CommonModule } from '@angular/common';
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { CheckInDataAccessModule } from '@nrwl-airlines/check-in/data-access';
import { SharedDataAccessModule } from '@nrwl-airlines/shared/data-access';

import { ShellComponent } from './shell/shell.component';

const routes: Routes = [
  {
    path: '',
    component: ShellComponent,
    children: [
      {
        path: '',
        pathMatch: 'full',
        redirectTo: 'seatmap', // 👈
      },
      {
        path: 'seatmap', // 👈
        loadChildren: () =>
          import('@nrwl-airlines/seatmap/feature-seat-listing')
            .then(esModule => esModule.SeatmapFeatureSeatListingModule),
      },
    ],
  },
];

@NgModule({
  declarations: [ShellComponent],
  exports: [RouterModule],
  imports: [
    RouterModule.forRoot(routes),
    SharedDataAccessModule,
    CheckInDataAccessModule,
    CommonModule,
  ],
})
export class CheckInFeatureShellModule {}

#angular #angular-cli #angular-workspace #monorepo #nx #series-angular-architectural-patterns #ngrx