Table of Contents
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 simply 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 the green ones are the children of the yellow ball. Please remember tree structure has no child limit so green children can also have a 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 a dummy data array to make a screen with 2 parents having multiple child hierarchies 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 command line interface to make our React Native App.
If you have previously installed a global react-native-cli package, please remove it as it may cause unexpected issues:
npm uninstall -g react-native-cli @react-native-community/cli
Run the following commands to create a new React Native project
npx react-native init ProjectName
If you want to start a new project with a specific React Native version, you can use the --version argument:
npx react-native init ProjectName --version X.XX.X
Note If the above command is failing, you may have old version of react-native
or react-native-cli
installed globally on your pc. Try uninstalling the cli and run the cli using npx.
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 dependencies 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
// React Native Tree View for Android and IOS devices
// https://aboutreact.com/react-native-final-tree-view/
// import React in our code
import React from 'react';
// import all the components we are going to use
import {SafeAreaView, Text, View} from 'react-native';
//import library for the TreeView
import TreeView from 'react-native-final-tree-view';
//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',
},
],
},
],
},
],
};
const getIndicator = (isExpanded, hasChildrenNodes) => {
if (!hasChildrenNodes) {
return '*';
} else if (isExpanded) {
return '-';
} else {
return '+';
}
};
const App = () => {
return (
<SafeAreaView style={{flex: 1}}>
<View style={{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>
</SafeAreaView>
);
};
export default App;
To Run the React Native App
Open the terminal again and jump into your project using.
cd ProjectName
1. Start Metro Bundler
First, you will need to start Metro, the JavaScript bundler that ships with React Native. To start Metro bundler run following command
npx react-native start
Once you start Metro Bundler it will run forever on your terminal until you close it. Let Metro Bundler run in its own terminal. Open a new terminal and run the application.
2. Start React Native Application
To run the project on an Android Virtual Device or on real debugging device
npx react-native run-android
or on the iOS Simulator by running (macOS only)
npx react-native run-ios
Output 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 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. 🙂
I am implimenting TreeView in React Native same like mentioned above, but I am getting error as below:
Invariant Violation: Element type is invalid: expected a string(for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your vomponent from the file it’s defined in, or you might have mixed up default and named imports.
Please help me to fix this error.
Hello Sumit,
Thanks for informing. Post has been updated for the same.
HI,
Did you face issue like Yoganode, i got Yoganode issue..
Could you please help me how to fix
Nope but yeah from some solution on internet you need to use TreeView inside a view instead using it directly.
Hi
Is it possible to add style for Tree view. I tried in this example but not able to achieve properly. Please suggest.
you can see there is a style in the Text component which will help you to customize the style. if you still have no clue how to do it then can you please draw and send it to me on aboutreact11@gmail.com?
Hi, I want to modify the rendernode UI with 2 textview and Image, is it possible to edit?
If yes could you please help me how to edit..
Thanks
Please check the code in your inbox or see snack here https://snack.expo.io/Sk8rlCAEU