jtfell-svelte-scrollyteller

Svelte Scrollyteller

A scrollyteller component for Svelte. Svelte port of the ABC News React Scrollyteller.

Usage

The scrollyteller takes a series of panels of content nodes and turns them into a series of elements which scroll over the <Scrollyteller> component's children.

The panels prop is in the format of:

[
  {
    data: {
      info: 'Some kind of config that is given when this marker is active'
    },
    nodes: [<DOM elements for this panel>]
  },
  {
    data: {
      thing: 'This will be given when the second marker is hit'
    },
    nodes: [<DOM elements for this panel>]
  }
]

When a new box comes into view onMarker will be called with the data of the incoming panel.

<script lang="ts">
  import Scrollyteller from 'svelte-scrollyteller/Scrollyteller.svelte';
  import UpdatableGraphic from 'UpdatableGraphic.svelte'

  export let panels;

  let marker = 0;
  let progress;

  const markerChangeHandler = (data) => {
    marker = data;
  }

  const progressChangeHandler = (data) => {
    progress = data;
  }
</script>

<Scrollyteller
  {panels}
  onMarker={markerChangeHandler}
  onProgress={progressChangeHandler}
>
  <UpdatableGraphic marker={marker} />
</Scrollyteller>

For a more complete example using Typescript see the examples.

Props

Property	Type	Description	Default
panels	Refer to Usage	required Array of nodes and data which dictate the markers
onMarker	(marker) => void	required Function which fires when a marker intersects and returns that markers data
onProgress	(progress) => void	Function which fires when a on scroll and returns the scrollyteller progress
customPanel	Svelte Component	Component to replace the default panel component	Panel.svelte
observerOptions	IntersectionObserverInit	Options for the intersection observer. Refer to the docs	{threshold: 0.5}

Usage with Odyssey

When developing ABC News stories with Odyssey you can use the loadScrollyteller function to gather panels within a CoreMedia article.

See a more complete usage example with Odyssey.

CoreMedia text:

#scrollytellerVARIABLEvalue
This is the opening paragraph panel
#markVARIABLEvalue
This is a second panel
#markVARval
This is another paragraph
#endscrollyteller

JS Code:

import { loadScrollyteller } from 'svelte-scrollyteller/utils';
import App from 'App.svelte';

const scrollyData = loadScrollyteller(
  "",       // If set to eg. "one" use #scrollytellerNAMEone in CoreMedia
  "u-full", // Class to apply to mount point u-full makes it full width in Odyssey
  "mark"    // Name of marker in CoreMedia eg. for "point" use #point default: #mark
);

new App({
  target: scrollyData.mountNode,
  props: { panels: scrollyData.panels }
});

Example

Mostly to aid development and demonstrate usage, there is an example project in /examples. It uses aunty as the build tool to match the usual ABC News interactive development work flow.