Angular Infinite Scroll

Inspired by ng-infinite-scroll directive for angular (> 2).

Angular Support

Supports in Angular - Final - 2.x.x

Angular Consulting Services

I'm a Senior Javascript Engineer & A Front End Consultant at Orizens. My services include:

• consulting to companies and startups on how to approach code in their projects and keep it maintainable.
• I provide project bootstrapping and development - while afterwards, I integrate it on site and guide the team on it.

Contact Me Here

Installation

npm install angular2-infinite-scroll --save

Supported API

Currently supported attributes:

• infiniteScrollDistance<number> - (optional, default: 2) - should get a number, the number of viewport lengths from the bottom of the page at which the event will be triggered.
• infiniteScrollUpDistance<number> - (optional, default: 1.5) - should get a number
• infiniteScrollThrottle<number> - (optional, default: 300) - should get a number of milliseconds for throttle. The event will be triggered this many milliseconds after the user stops scrolling.
• infiniteScrollContainer<string|HTMLElement> - (optional, default: null) - should get a html element or css selector for a scrollable element; window or current element will be used if this attribute is empty.
• scrolled<function> - this will callback if the distance threshold has been reached on a scroll down.
• scrolledUp<function> - (event: InfiniteScrollEvent) - this will callback if the distance threshold has been reached on a scroll up.
• scrollWindow<boolean> - (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.
• immediateCheck<boolean> - (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).
• infiniteScrollDisabled<boolean> - (optional, default: false) - doesn't invoke the handler if set to true

Behavior

By default, the directive listens to the 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

DEMO

• Default Scroll By Window - plunkr
• Scroll On a "Modal" - plunkr

Usage

First, import the InfiniteScrollModule to your module:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { InfiniteScrollModule } from 'angular2-infinite-scroll';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppComponent } from './app';

@NgModule({
  imports:[ BrowserModule, InfiniteScrollModule ],
  declarations: [ AppComponent, ],
  bootstrap: [ AppComponent ]
})
export class AppModule { }

platformBrowserDynamic().bootstrapModule(AppModule);

In this example, the onScroll callback will be invoked when the window is scrolled down:

import { Component } from '@angular/core';

@Component({
	selector: 'app',
	template: `
		<div class="search-results"
		    infinite-scroll
		    [infiniteScrollDistance]="2"
		    [infiniteScrollThrottle]="300"
		    (scrolled)="onScroll()">
		</div>
	`
})
export class AppComponent {
	onScroll () {
	    console.log('scrolled!!')
	}
}

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

import { Component } from '@angular/core';

@Component({
	selector: 'app',
	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 AppComponent {
	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 AppComponent {
	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)