How to get started with Canvas animations in Angular

Or how my dreams of writing a game started by animating a square block#

I love playing games. And I love coding too. So, one day, I got thinking, why not use those coding skills to make a game? But it sounds hard. How would one even get started?

With baby steps.

First, we need some 2D graphics. In this case, it’s moving some blocks on the screen. So, in this article, I will show how to draw and animate objects using the HTML5 Canvas and JavaScript. I will also go through some techniques to optimize performance. Who knows, it might come in handy some day.

Introduction#

Apple introduced canvas in 2004 to power applications and the Safari browser. A few years later it was standardized by the WHATWG. It comes with finer grained control over rendering but with the cost of having to manage every detail manually. In other words, it can handle many objects, but we need to code everything in detail.

The canvas has a 2D drawing context used for drawing shapes, text, images, and other objects. First, we choose the color and brush, and then we paint. We can change the brush and color before every new drawing, or we can continue with what we have.

Canvas uses immediate rendering: When we draw, it immediately renders on the screen. But, it is a fire-and-forget system. After we paint something, the canvas forgets about the object and only knows it as pixels. So there is no object that we can move. Instead, we have to draw it again.

Doing animations on Canvas is like making a stop-motion movie. In every frame need to move the objects a little bit to animate them.

Using Canvas#

To get started, we need to add a canvas element in our HTML. We’ll also attach a reference variable to the element so that we’ll be able to refer to it from the component class:

<canvas #canvas width="600" height="300"></canvas>
<>

In the component class, we can then use the @ViewChild() decorator to inject a reference to the canvas.

In Angular 8, a new static flag has been introduced not to break existing applications. Read more about it here. Since I want access to the canvas in the ngOnInit hook I set it to true.

@ViewChild('canvas', { static: true }) 
canvas: ElementRef<HTMLCanvasElement>;
<>

Once the component has initialized, we’ll have access to the Canvas DOM node, as well as its drawing context:

this.ctx = this.canvas.nativeElement.getContext('2d');
<>

Here is the starting code for the component:

import { Component, ViewChild, ElementRef, OnInit } from '@angular/core';

@Component({
  selector: 'app-root',
  template: `
    <canvas #canvas width="600" height="300"></canvas>
    <button (click)="animate()">Play</button>   
  `,
  styles: ['canvas { border-style: solid }']
})
export class AppComponent implements OnInit {
  @ViewChild('canvas', { static: true })
  canvas: ElementRef<HTMLCanvasElement>;  

  private ctx: CanvasRenderingContext2D;

  ngOnInit(): void {
    this.ctx = this.canvas.nativeElement.getContext('2d');
  }

  animate(): void {}
}

#angular #graphics #fun

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How to get started with Canvas animations in Angular
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

Clara  Gutmann

Clara Gutmann

1598712540

Angular HttpClient Module | Angular Http GET, POST Example

Angular 9 HttpClient is an inbuilt module that helps us to send network requests to any server. Angular HttpClientModule is used to send GET, POST, PUT, PATCH, and DELETE requests. Angular can consume REST API using the Angular HttpClient module. The latest version of the Angular framework is  Angular 9.

If you are new to Angular 9, then check out my  Angular 9 Tutorial in this blog. Most front-end applications communicate with the backend services over an HTTP protocol. Modern browsers support the two different APIs for making HTTP requests.

  1. XMLHttpRequest interface and the
  2. fetch() API.

We will use XMLHttpRequest for Angular application.

#angular #angular httpclient #angular http #post #get

Shawn  Durgan

Shawn Durgan

1593140880

How to get started with Canvas animations in Angular

Using Canvas

To get started, we need to add a canvas element in our HTML. We’ll also attach a reference variable to the element so that we’ll be able to refer to it from the component class:

<canvas #canvas width="600" height="300"></canvas>

In the component class, we can then use the @ViewChild() decorator to inject a reference to the canvas.

In Angular 8, a new static flag has been introduced not to break existing applications. Read more about it here. Since I want access to the canvas in the ngOnInit hook I set it to true.

@ViewChild('canvas', { static: true }) 
canvas: ElementRef<HTMLCanvasElement>;

Once the component has initialized, we’ll have access to the Canvas DOM node, as well as its drawing context:

this.ctx = this.canvas.nativeElement.getContext('2d');

Here is the starting code for the component:

import { Component, ViewChild, ElementRef, OnInit } from '@angular/core';

@Component({
  selector: 'app-root',
  template: `
    <canvas #canvas width="600" height="300"></canvas>
    <button (click)="animate()">Play</button>   
  `,
  styles: ['canvas { border-style: solid }']
})
export class AppComponent implements OnInit {
  @ViewChild('canvas', { static: true })
  canvas: ElementRef<HTMLCanvasElement>;  

  private ctx: CanvasRenderingContext2D;

  ngOnInit(): void {
    this.ctx = this.canvas.nativeElement.getContext('2d');
  }

  animate(): void {}
}

#angular #graphics #fun #canvas

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

Guide to Get Started with Canvas animation in Angular

In this article, you learned how to use the HTML5 Canvas and its 2D graphics context. I showed how to draw simple shapes, and finally, we were able to animate multiple objects on the canvas.

#angular #canvas