Dylan North

Dylan North

1567434760

Angular Scope Tutorial

1. Overview

In this post, we are reviewing scope in Angular. It is passed as an argument when we make a controller:

<script>
var myApp = angular.module('myApp', []);

myApp.controller(‘myController’, function($scope) {

$scope.name = “Red Dead Redemption”;

});

</script>

Scope is actually an object that refers to the model in an application structure, such as Model View Controller (MVC) .

It provides definitions – also known as context – for JavaScript-like code snippets called expressions. Scopes are structured in a hierarchy that mimics the Document Object Model (DOM) structure of the application. Scopes can watch expressions and propagate events in a similar way to DOM events.

2. Scope Is a Data Model

What does it mean for Scope to be a data model? It is a JavaScript object with properties and methods that can be accessed by both the view and controller:

Here, we have an example that demonstrates how modifying the view can affect the controller and model:

<!DOCTYPE html>

<html>

<script src = “https://ajax.googleapis.com/ajax/libs/angularjs/1.7.5/angular.min.js”></script>

<body>


<div ng-app=“demoApp” ng-controller=“demoCtrl”>


<input ng-model=“word”>


<h1>Hello, {{word}}!</h1>


</div>


<script>

var app = angular.module(‘demoApp’, []);

app.controller(‘demoCtrl’, function($scope) {

$scope.word = “word”;

});

</script>


<p>If we change the word in the input field, the change will affect the model and the word property in the controller.</p>


</body>

</html>

Feel free to copy and paste that code into your favorite text editor or download the file from my GitHub.

In this simple example, if we modify the input in the web page, we see the value change for the greeting in the <h1> tags:

3. Root Scope and Hierarchies

Each Angular application has only one root scope but can have any number of child scopes.

An application can have several scopes because directives can create new child scopes. When new scopes are created, they become children of their parent scope. This creates a tree structure which parallels the DOM where they’re attached.

The example below, which is available in my GitHub, shows how multiple scopes work in an application and also prototypal inheritance of properties:

<script src = “https://ajax.googleapis.com/ajax/libs/angularjs/1.7.5/angular.min.js”></script>

<script>

(function(angular) {

‘use strict’;

angular.module(‘scopeExample’, [])

.controller(‘HelloController’, [‘$scope’, ‘$rootScope’, function($scope, $rootScope) {

$scope.name = ‘World’;

$rootScope.department = ‘Red Dead Redemption 2’;

}])

.controller(‘ListController’, [‘$scope’, function($scope) {

$scope.names = [‘Arthur’, ‘Dutch’, ‘Bill’];

}]);

})(window.angular);


</script>


</head>

<body ng-app=“scopeExample”>

<div class=“show-scope-demo”>

<div ng-controller=“HelloController”>

Hello {{name}}!

</div>

<div ng-controller=“ListController”>

<ol>

<li ng-repeat=“name in names”>{{name}} from {{department}}</li>

</ol>

</div>

</div>

The page will display like this:

In the code shown above, when [[name]] is evaluated by Angular, it first looks at the scope associated with the value for the ng-controller attribute for the name property. This is why it says “Hello World!” on top rather than a character name from Red Dead Redemption 2.

If the property is not found, it searches the parent scope and so on until the root scope is reached. The Angular documentation calls this prototypical inheritance, while others like Mozilla call it prototypal inheritance.

Regardless of what it’s truly called, what we need to know is JavaScript only has one construct: objects. Every object has a private property that holds a link to another object called its prototype.

4. Conclusion

Today we reviewed the core concepts of scope in Angular. We reviewed that it is an object that resides in the model of an application, that it is hierarchical and has prototypal inheritance, and, there can only be one root scope.

Angular can be used effectively with the Spring Framework. To learn more Angular, I will be checking out courses on Udemy and Treehouse.

Originally published by  Michael Good at dzone.com

==========================================

Thanks for reading :heart: If you liked this post, share it with all of your programming buddies! Follow me on Facebook | Twitter

Learn More

☞ Angular 8 (formerly Angular 2) - The Complete Guide

☞ Complete Angular 8 from Zero to Hero | Get Hired

☞ Learn and Understand AngularJS

☞ The Complete Angular Course: Beginner to Advanced

☞ Angular Crash Course for Busy Developers

☞ Angular Essentials (Angular 2+ with TypeScript)

☞ Angular (Full App) with Angular Material, Angularfire & NgRx

☞ Angular & NodeJS - The MEAN Stack Guide


#angular #web-development

What is GEEK

Buddha Community

Angular Scope Tutorial
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

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

akshay L

akshay L

1613737472

Angular Tutorial | Angular Tutorial For Beginners | Angular Training | Intellipaat

In this Angular tutorial you will learn what is angular, angular architecture, what is typescript, Data binding & interpolation, angular components, Variable Declaration & Function Declaration, Encapsulation & Polymorphism in Angular, Angular Routing and Navigation, various angular basic & advanced concepts, hands-on demo on how to import & export data in angular, Angular JS vs Angular vs React JS and angular CLI among others.

#angular tutorial #angular tutorial for beginners #angular training

Salman Ahmad

1588747755

Deploy Angular 10/9 App to Production with Firebase Hosting

In this tutorial, I am going to share with you How to Deploy Angular 10/9 App to Production with Firebase Hosting?.

#angular #firebase #popular tutorials #angualr firebase deploy #angular app #angular tutorial #firebase tutorial

Ayyaz Zafar

1624138795

Angular Material Autocomplete - Multiple Use Cases covered

Learn How to use Angular Material Autocomplete Suggestions Search Input. I covered multiple use cases.

Please watch this video. I hope this video would be helpful for you to understand it and use it in your projects

Please subscribe: https://www.youtube.com/channel/UCL5nKCmpReJZZMe9_bYR89w

#angular #angular-material #angular-js #autocomplete #angular-material-autocomplete #angular-tutorial