react native search and scroll to hit

Question

I need some help implementing a search and scroll to hit in react native. Did a lot of searches and ended up in some dead ends (found some refs examples I couldn't get to work).

Tried building this snippet as a kick-off:

https://snack.expo.io/@norfeldt/searching-and-scroll-to

import React, { Component } from 'react';
import { Text, View, ScrollView, TextInput, StyleSheet } from 'react-native';

export default class App extends Component {

  state = {
    text: '41'
  }

  render() {
    return (
      <View style={styles.container}>

      <TextInput
        style={{height: 60, borderColor: 'gray', borderWidth: 1, borderRadius: 10, margin: 5, padding:30, color: 'black', }}
        onChangeText={(text) => this.setState({text})}
        value={this.state.text}
      />

      <ScrollView >

          {[...Array(100)].map((_, i) => {return <Text style={styles.paragraph} key={i}>{i}</Text>})}

      </ScrollView>

      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    paddingTop: 10,
    backgroundColor: '#ecf0f1',
  },
  paragraph: {
    margin: 10,
    fontSize: 18,
    fontWeight: 'bold',
    textAlign: 'center',
    color: '#34495e',
  },
});

Any help getting started would be appreciated.

Answer 1

My guess would be:

You could start by binding a ref of your <ScrollView/>.

// ScrollView Ref.
<ScrollView ref={(ref) => this['ScrollView'] = ref}>
  ...
</ScrollView>

And each of your <Text/> components (by index).

// Text Refs.
<Text ref={(ref) => this[i] = ref} style={styles.paragraph} key={i}>{i}</Text>

You could then set a submit() function.

Said function could find the ref equal to this.state.text using a try catch statement for graceful failure in edge cases.

If found; target x and y offset could be retrieved using measure()

scrollTo() could then be called to scroll to the target component.

// Scroll To Query.
submit = () => {

  try {

    const { text } = this.state // Text.
    const target = this[text] // Target.

    // Locate Target.
    target.measure((framex, framey, width, height, x, y) => {

      // Scroll To Target.
      this.ScrollView.scrollTo({x, y, animated: true})
    })

  } catch (error) {

    return console.log(error)
  }

}