React Native Image Placeholder

Load images incrementally to provide a better User Experience.

If you want to download larger images but provide with a nice transition while the users are waiting for the image you can provide with a smaller version of the image (as you can see on the examples).

This is inspired on how medium loads the articles and the iron-image component from the polymer library works by providing the option to present the larger image and give to the user a hint of the presence of an image, specially on slower connections.

It basically fetchs an image an tracks the progress of the image once is ready it shows the user the requeested image but during the period of loading the user can show a spinner or at least a hint of the image in a smaller version.

Examples

Multiple Images.

Single Image.

Installation

npm install --save react-native-image-with-placeholder

Getting started

Import the file as specified on the installation steps. Then import the Component where you have plans to use it, for example:

import ImagePlaceholder from 'react-native-image-with-placeholder'

And inside of the render method of your component add the component with the properties you require.

Basic usage

<ImagePlaceholder 
  style={{ flex: 1 }}
  duration={1000}
  activityIndicatorProps={{
    size: 'large',
    color: 'green',
  }}
  src='https://s3.amazonaws.com/crisoforo.com/flowers.jpg' 
  placeholder='https://s3.amazonaws.com/crisoforo.com/flowers-small.jpg'
  />
);

Multiple images with different transition speed

render() {
  return (
    <View style={styles.container}>
      <ImagePlaceholder 
        style={styles.item}
        src='https://s3.amazonaws.com/crisoforo.com/airplane.jpg' 
        placeholder='https://s3.amazonaws.com/crisoforo.com/airplane-mini.jpg'
      />
      <ImagePlaceholder 
        style={styles.item}
        duration={3000}
        src='https://s3.amazonaws.com/crisoforo.com/flowers.jpg' 
        placeholder='https://s3.amazonaws.com/crisoforo.com/flowers-small.jpg'
      />
      <ImagePlaceholder 
        style={styles.item}
        duration={1000}
        src='https://s3.amazonaws.com/crisoforo.com/sun.jpg' 
        placeholder='https://s3.amazonaws.com/crisoforo.com/sun-small.jpg'
      />
    </View>
    )
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    flexWrap: 'wrap',
  },
  item: {
    flex: 1,
  }
});

API

Props	Type	Optional	Default	Description
src	String	false	null	The url of the main image to be fetched.
placeholder	String	true	null	The smaller image present before the main image is ready if is not present it will show an `ActivityIndicator` component instead.
style	View.propTypes.style	true	Container Style	Style applied to the image container
imageStyle	Object	true	null	The styles appliead to the main image.
placeholderStyle	Object	true	null	The styles applied to the placeholder image.
placeholderContainerStyle	Object	true	null	The styles applied to the container `View` of the placeholder image.
duration	Integer	true	750	Time in miliseconds used to transition to the original image once is ready.
showActivityIndicator	Boolean	true	true	If `true` an `ActivityIndicator` should be displayed while the placeholder image is being fetch or if is not present.
activityIndicatorProps	Object	true	null	Options to pass to the `ActivityIndicator` component such as `size`, `color` or `style`.
`ActivityIndicator`	Component	true	null	If present it will render this instead of the `ActivityIndicator` component and `activityIndicatorProps` is no longer used and valid.

mitogh / react-native-image-placeholder

readme