React Native Tree View for Android and IOS devices

React Native Tree View

This is an example to create a React Native Tree View using react-native-final-tree-view for Android and IOS devices. A Tree View is simple a hierarchical view that is used to show the parent-child relationship between the data. You can simply understand the Tree View using the following image. In the below image the yellow ball is the parent and green ones are the children of the yellow ball. Please remember tree structure has no child limit so green children can also have the child and there can be more children under them.

In this example, we will see how to create a TreeView in React Native. So let’s get started.

We are going to use TreeView component from  react-native-final-tree-view library.

Import TreeView using

import TreeView from 'react-native-final-tree-view';

To Show TreeView

<TreeView
  data={state.data}
  renderNode={({ node, level, isExpanded, hasChildrenNodes }) => {
    return (
      <View>
        <Text
          style={{
            marginLeft: 25 * level,
            fontSize: 18,
          }}>
          {getIndicator(isExpanded, hasChildrenNodes)} {node.name}
        </Text>
      </View>
    );
  }}
/>

For this example, we are going to use dummy data array to make a screen with 2 parents having multiple child hierarchy under them.

To Make a React Native App

Getting started with React Native will help you to know more about the way you can make a React Native project. We are going to use react-native init to make our React Native App. Assuming that you have node installed, you can use npm to install the react-native-cli command line utility. Open the terminal and go to the workspace and run

npm install -g react-native-cli

Run the following commands to create a new React Native project

react-native init ProjectName

If you want to start a new project with a specific React Native version, you can use the --version argument:

react-native init ProjectName --version X.XX.X

react-native init ProjectName --version react-native@next

This will make a project structure with an index file named App.js in your project directory.

Installation of Dependency

To use TreeView we need to install react-native-final-tree-view dependency.

To install this open the terminal and jump into your project using

cd ProjectName

Run the following command to install

npm install react-native-final-tree-view --save

This command will copy all the dependency into your node_module directory.

–save is optional, it is just to update the react-native-final-tree-view dependency in your package.json file.

Code

Now Open App.js in any code editor and replace the code with the following code

App.js

/*Example of React Native Tree View*/
import React from 'react';
//import React
import { Text, View } from 'react-native';
//import Basic React Native components
import TreeView from 'react-native-final-tree-view';
//import library for the TreeView

//Dummy data for the Tree View
const state = {
  data: [
    {
      id: 'Parent1',
      name: 'Parent1',
      children: [
        {
          id: 'child1',
          name: 'child1',
          children: [
            {
              id: 'child11',
              name: 'child11',
              children: [
                {
                  id: 'child111',
                  name: 'child111',
                },
              ],
            },
            {
              id: 'child12',
              name: 'child12',
            },
          ],
        },
      ],
    },
    {
      id: 'Parent2',
      name: 'Parent2',
      children: [
        {
          id: 'child2',
          name: 'child2',
          children: [
            {
              id: 'child21',
              name: 'child21',
            },
            {
              id: 'child22',
              name: 'child22',
            },
          ],
        },
      ],
    },
  ],
};

function getIndicator(isExpanded, hasChildrenNodes) {
  if (!hasChildrenNodes) {
    return '*';
  } else if (isExpanded) {
    return '-';
  } else {
    return '+';
  }
}

function App() {
  return (
    <View
      style={{
        flex: 1,
        marginTop: 30,
        backgroundColor: 'white',
        padding: 10,
      }}>
      <TreeView
        data={state.data}
        renderNode={({ node, level, isExpanded, hasChildrenNodes }) => {
          return (
            <View>
              <Text
                style={{
                  marginLeft: 25 * level,
                  fontSize: 18,
                }}>
                {getIndicator(isExpanded, hasChildrenNodes)} {node.name}
              </Text>
            </View>
          );
        }}
      />
    </View>
  );
}

export default App;

To Run the React Native App

Open the terminal again and jump into your project using.

cd ProjectName

To run the project on an Android Virtual Device or on real debugging device

react-native run-android

or on the iOS Simulator by running

react-native run-ios (macOS only).

Output Screenshots

Screenshots

Output in Online Emulator

This is how you can make a React Native Tree View for Android and IOS using react-native-final-tree-view. If you have any doubts or you want to share something about the topic you can comment below or contact us here. There will be more posts coming soon. Stay tuned!

Hope you liked it. 🙂