jcmcallister/angular-inviewport

A simple lightweight library for Angular with no other dependencies that detects when an element is within the browser viewport and adds a "sn-viewport-in" or "sn-viewport-out" class to the element

Angular InViewport

This project was generated with Angular CLI version 1.5.4.

A simple lightweight library for Angular with no other dependencies that detects when an element is within the browser viewport and adds a sn-viewport-in or sn-viewport-out class to the element.

This is a simple library for Angular, implemented in the Angular Package Format v5.0.

Install

via NPM

npm i @thisissoon/angular-inviewport --save

via Yarn

yarn add @thisissoon/angular-inviewport

app.module.ts

import { InViewportModule } from '@thisissoon/angular-inviewport';

const providers = [
  { provide: WindowRef, useValue: window }
];

@NgModule({
  imports: [
    // provide WindowRef class by using an window object
    InViewportModule.forRoot(providers)
  ]
})
export class AppModule { }

app.server.module.ts // Only required if using Angular Universal

import { InViewportModule } from '@thisissoon/angular-inviewport';

@NgModule({
  imports: [
    // no need to pass any arguments to forRoot
    // function for server module
    InViewportModule.forRoot()
  ]
})
export class AppServerModule { }

Examples

Just using classes

app.component.html

<p class="foo" snInViewport>Amet tempor excepteur occaecat nulla.</p>

app.component.css

.foo {
  transition: transform .35s ease-out;
}

.foo.sn-viewport-out {
  transform: translateY(-30px);
}

.foo.sn-viewport-in {
  transform: translateY(0);
}

Using events

app.component.html

<p class="foo" snInViewport (inViewportChange)="onInViewportChange($event)">
  Amet tempor excepteur occaecat nulla.
</p>

app.component.ts

export class AppComponent {
  highlight = false;

  onInViewportChange(inViewport: boolean) {
    this.highlight = inViewport;
  }
}

app.component.css

.highlight {
  background-color: yellow;
}

Specify debounce time (default: 100ms)

app.component.html

<p class="foo" snInViewport [debounce]="500">
  Amet tempor excepteur occaecat nulla.
</p>

Specify parent scrollable element

Useful if element is within another scrollable element

app.component.html

<div #container>
  <p class="foo" snInViewport [debounce]="500" [parent]="container">
    Amet tempor excepteur occaecat nulla.
  </p>
</div>

Trigger inviewport check manually

Window scroll and resize events doesn't cover all potential use cases for the inViewport status check. For example if using directive inside a carousel. To trigger a check manually simply assign a template variable value to the directive and call calculateInViewportStatus when you require.

app.component.html

<p snInViewport #foo="snInViewport">
  Amet tempor excepteur occaecat nulla.
</p>

<button (click)="foo.calculateInViewportStatus()">Check status</button>

Development server

Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any of the source files.

Code scaffolding

Run ng generate component component-name to generate a new component. You can also use ng generate directive|pipe|service|class|guard|interface|enum|module.

Build

Run ng build to build the project. The build artifacts will be stored in the dist/ directory. Use the -prod flag for a production build.

Running unit tests

Run ng test to execute the unit tests via Karma.

Running end-to-end tests

Run ng e2e to execute the end-to-end tests via Protractor.

Making Commits

This repo uses Commitizen CLI and Conventional Changelog to create commits and generate changelogs. Instead of running git commit run git cz and follow the prompts. Changelogs will then be generated when creating new releases by running npm run release.

Making Releases

Run npm run release to create a new release. This will use Standard Version to create a new release. Standard Version will generate / update the changelog based on commits generated using Commitizen CLI, update the version number following semantic versioning rules and then commit and tag the commit for the release. Simply run git push --follow-tags origin master.

Further help

To get more help on the Angular CLI use ng help or go check out the Angular CLI README.