Components

Girders Element's components package is a library of custom components that aid in building React and React Native apps.

Available Components

Viewport Tracker

Tracks the position and size of a ScrollView or ListView viewport. Communicates it to all viewport aware child components.

Usage

import { Viewport } from '@girders-elements/components';

render() {
  return (
    <Viewport.Tracker>
      <ScrollView>
        { this.props.children }
      </ScrollView>
    </Viewport.Tracker>
  );
}

Viewport Aware

A higher-order component that processes the information communicated by the viewport tracker. Determines whether the wrapped component is in or outside the viewport. Updates the inViewport parameter of the wrapped component accordingly.

Usage

import { Image } from 'react-native';
import { Viewport } from '@girders-elements/components';
const ViewportAwareImage = Viewport.Aware(Image);

render() {
  return (
    <ViewportAwareImage
      source={{uri: 'https://facebook.github.io/react/img/logo_og.png'}}
      preTriggerRatio={0.5} />
  );
}

Properties

| Prop | Description | Default | |---|---|---| |preTriggerRatio| Determines pre-triggering of inViewport. Useful for rendering components beforehand to improve user experience. A ratio of 0.5 means that the effective viewport will be twice the size of the real viewport. | 0 |

With Place Holder

A higher-order component that can be used to display a place holder while the component is not in the viewport. This can improve user experience.

Usage

import { Image, View } from 'react-native';
import { Viewport } from '@girders-elements/components';

const PlaceHolder = () => <View style={{ width: 50, height: 50, backgroundColor: 'darkgrey' }} />

const ViewportAwareImageWithPlaceholder = Viewport.Aware(Viewport.WithPlaceHolder(Image, PlaceHolder));

render() {
  return (
    <ViewportAwareImageWithPlaceholder
      source={{uri: 'https://facebook.github.io/react/img/logo_og.png'}}
      preTriggerRatio={0.5}
      style={{ width: 50, height: 50 }} />
  );
}

Properties

| Prop | Description | Default | |---|---|---| |placeHolder| Useful for passing down a place holder at render time. | null |