Angular 2 Infinite Scroll
A port & modification of ng-infinite-scroll directive for angular 2.
Angular 2 Support
Updated to support Angular 2 - Final - 2.0.0
Installation
npm install angular2-infinite-scroll --save
Supported API
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).
- (boolean) - "infiniteScrollDisabled" (optional, default: false) - doesn't invoke the handler if set to true
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
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]="500"
(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