angular2-infinite-scroll

Angular 2 Infinite Scroll

A port & modification of ng-infinite-scroll directive for angular 2.

Installation

npm install angular2-infinite-scroll --save

Supported API

The directive triggers Currently supported attributes:

• (number) "infiniteScrollDistance" (optional, default: 2) - should get a number, the number of viewport lenghts from the bottom of the page at which the event will be triggered.
• (number) "infiniteScrollUpDistance" (optional, default: 1.5) - should get a number
• (number) "infiniteScrollThrottle" (optional, default: 300) - should get a number of milliseconds for throttle. The event will be triggered this many milliseconds after the user stops scrolling.
• (function) - instead of defining a callback function on the "infinite-scroll" attribute, you should use the event binding (scrolled)="handleScrollDownCallback()" - this will callback if the distance threshold has been reached on a scroll down.
• (function) - instead of defining a callback function on the "infinite-scroll" attribute, you should use the event binding (scrolledUp)="handleScrollUpCallback()" - this will callback if the distance threshold has been reached on a scroll up.
• (boolean) - "scrollWindow" (optional, default: true) - listens to the window scroll instead of the actual element scroll. this allows to invoke a callback function in the scope of the element while listenning to the window scroll.
• (boolean) - "immediateCheck" (optional, default: false) - invokes the handler immediately to check if a scroll event has been already triggred when the page has been loaded (i.e. - when you refresh a page that has been scrolled).

Behavior

By default, the directive listens to a window scroll event and invoked the callback. To trigger the callback when the actual element is scrolled, these settings should be configured:

• [scrollWindow]="false"
• set an explict css "height" value to the element

Usage

See a live example at this plunkr In this example, the onScroll callback will be invoked when the window is scrolled down:

import { Component } from '@angular/core';
import { InfiniteScroll } from 'angular2-infinite-scroll';

@Component({
	selector: 'app',
	directives: [ InfiniteScroll ],
	template: `
		<div class="search-results"
		    infinite-scroll
		    [infiniteScrollDistance]="2"
		    [infiniteScrollThrottle]="500"
		    (scrolled)="onScroll()">
		</div>
	`
})
export class App {
	onScroll () {
	    console.log('scrolled!!')
	}
}

in this example, whenever the "search-results" is scrolled, the callback will be invoked:

import { Component } from '@angular/core';
import { InfiniteScroll } from 'angular2-infinite-scroll';

@Component({
	selector: 'app',
	directives: [ InfiniteScroll ],
	styles: [
		`.search-results {
			height: 20rem;
			overflow: scroll;
		}`
	],
	template: `
		<div class="search-results"
		    infinite-scroll
		    [infiniteScrollDistance]="2"
		    [infiniteScrollThrottle]="500"
		    (scrolled)="onScroll()"
		    [scrollWindow]="false">
		</div>
	`
})
export class App {
	onScroll () {
	    console.log('scrolled!!')
	}
}

In this example, the onScrollDown callback will be invoked when the window is scrolled down and the onScrollUp callback will be invoked when the window is scrolled up:

import { Component } from '@angular/core';
import { InfiniteScroll } from 'angular2-infinite-scroll';

@Component({
	selector: 'app',
	directives: [ InfiniteScroll ],
	template: `
		<div class="search-results"
		    infinite-scroll
		    [infiniteScrollDistance]="2"
		    [infiniteScrollUpDistance]="1.5"
		    [infiniteScrollThrottle]="500"
		    (scrolled)="onScrollDown()">
		    (scrolledUp)="onScrollUp()">
		</div>
	`
})
export class App {
	onScrollDown () {
	    console.log('scrolled down!!')
	}

	onScrollUp () {
    	console.log('scrolled up!!')
    }
}

Testing

To start developing tdd/bdd style: npm run dev This will: compile ts files, watch for changes and start the test task. Whenever a ts file is changed, it will rerun the tests.

Travis-ci is integrated

Credits For Tests Setup

ng2-test-seed has been a huge help and source of inspiration. At first, copy & paste, then, customisation to adapt to this code repository. Thanks @juliemr!

Showcase Examples

• Echoes Player Ng2 Version (github repo for echoes player)