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react-native-mirror

react-native-mirror

npm version dependencie status dev-dependency status npm npm travis build

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Installation

npm install --save react-native-mirror

or

yarn add react-native-mirror

Basic Usage

With react-native-mirror you can inject all properties of a component and forward the result of the prop-function to a clone of the component. The data can be forwarded to another prop or to an instance function of the same hirarchic component.

Let's say we have a the following viewtree and a "clone" of it:

const component = () => (
    <View>
        <ScrollView />
    </View>
)
 
// it has the same structure like the component above
const cloneComponent = () => (
    <View>
        <ScrollView />
    </View>
)

Now you want to forward the scroll position of the first <ScrollView /> to the second <ScrollView />. All you have to do is to wrap both components with the <Mirror /> component and add the scrollviewBootstrap variable from the lib to mirroredProps like below.

import Mirror, { scrollviewBootstrap } from 'react-native-mirror'
 
const component = () => (
    <Mirror mirroredProps={[scrollviewBootstrap]}>
        <View>
            <ScrollView />
        </View>
    </Mirror>
)
 
// it has the same structure like the component above
const cloneComponent = () => (
    <Mirror mirroredProps={[scrollviewBootstrap]}>
        <View>
            <ScrollView />
        </View>
    </Mirror>
)

Bootstraps

At the moment there are bootstraps for basic prop-forwarding for <ScrollView /> and all kinds of <TouchableHighlight />:

  • scrollviewBootstrap
  • touchableBootstrap

Simply add them to the mirroredProps property of the <Mirror />. The scrollviewBootstrap forwards the scroll position to the cloned <ScrollView /> ('s) and make it scroll to the same position.

Be careful with the touchableBootstrap. It forwards the onPress (onPressIn, onPressOut, ...) property to the clone. Keep in mind, that this triggers the property action also on the clone (maybe a download or navigation action or something).

Custom forwarding / injection

The mirroredProps property of the <Mirror /> takes an array of forwarding objects. The objects must have the folowing structure:

{
    // array of strings of component types. e.g.: 'ScrollView'
    componentTypes: React.PropTypes.array,
    // name of the property you want to forward. e.g.: 'onScroll'
    fromProp: React.PropTypes.string,
    
    // name of the clone-property which receives the data. e.g.: 'customScrollTo'
    toProp: React.PropTypes.string,
    // or
    // name of the clone-instanceMethod which receives the data. e.g.: 'scrollTo'
    toInstance: React.PropTypes.string,
    
    // function to extract the forwarding data 
    dataExtractor: React.PropTypes.func,
}

The dataExtractor receives the plain data from the property defined in fromProp and returns the data which should be forwarded...

Example with custom components

When you want to mirror custom components you have different choises. You can turn on the auto component detection with the property experimentalComponentDetection={true}, set on the <Mirror /> component. Like the name sais, this functionality is experimental...

When you don't want to use the auto detection you have to flag your custom components with a property mirrorClassComponent={true} or mirrorFunctionalComponent={true}. Be careful with this and make sure you set them properly (mirrorClassComponent for class components only and mirrorFunctionalComponent for functional components only!)

If you don't set them right your app will throw a error message "Cannot call a class as a function".

Example with auto detection

import Mirror, {
  scrollviewBootstrap,
  touchableBootstrap,
} from 'react-native-mirror'
 
export default class MirrorExample extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Mirror
            experimentalComponentDetection={true}
            mirroredProps={[
              scrollviewBootstrap,
              touchableBootstrap,
            ]}
        >
          <ExampleView />
        </Mirror>
        <Mirror 
            experimentalComponentDetection={true}
            mirroredProps={[
              scrollviewBootstrap,
              touchableBootstrap,
            ]}
        >
          <ExampleView />
        </Mirror>
      </View>
    )
  }
}

Example with manual component detection

In the following example i assume that the custom Component <ExampleView /> is a class component.

import Mirror, {
  scrollviewBootstrap,
  touchableBootstrap,
} from 'react-native-mirror'
 
export default class MirrorExample extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Mirror mirroredProps={[
          scrollviewBootstrap,
          touchableBootstrap,
        ]}>
          <ExampleView mirrorClassComponent={true}/>
        </Mirror>
        <Mirror mirroredProps={[
          scrollviewBootstrap,
          touchableBootstrap,
        ]}>
          <ExampleView mirrorClassComponent={true}/>
        </Mirror>
      </View>
    )
  }
}

API

prop name functionality
connectionId an Id that indicates which Mirrors are connected
containerStyle style the Mirror view-container (normaly not needed)
mirroredProps see the description in the topic above
experimentalComponentDetection mirrors custom components automatically (see description above)

Questions, enhancements or improvements?

... then open up an issue! :)