How to validate node text on rename in React

4 Sep 202624 minutes to read

You can validate the tree node text while editing using the nodeEditing event of the React Tree View (cancel the edit by setting args.cancel = true inside the event). The nodeEdited event fires after a successful rename and can also be used to react to the new value. Following is an example that shows how to validate and prevent empty values in tree node.

import * as ReactDOM from 'react-dom';
import * as React from 'react';
import { TreeViewComponent } from '@syncfusion/ej2-react-navigations';
import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
function App() {
    let treeObj;
    // Hierarchical data source for TreeView component
    let hierarchicalData = [
        { id: '01', name: 'Local Disk (C:)', expanded: true,
            subChild: [
                {
                    id: '01-01', name: 'Program Files',
                    subChild: [
                        { id: '01-01-01', name: 'Windows NT' },
                        { id: '01-01-02', name: 'Windows Mail' },
                        { id: '01-01-03', name: 'Windows Photo Viewer' },
                    ]
                },
                {
                    id: '01-02', name: 'Users', expanded: true,
                    subChild: [
                        { id: '01-02-01', name: 'Smith' },
                        { id: '01-02-02', name: 'Public' },
                        { id: '01-02-03', name: 'Admin' },
                    ]
                },
                {
                    id: '01-03', name: 'Windows',
                    subChild: [
                        { id: '01-03-01', name: 'Boot' },
                        { id: '01-03-02', name: 'FileManager' },
                        { id: '01-03-03', name: 'System32' },
                    ]
                },
            ]
        },
        {
            id: '02', name: 'Local Disk (D:)',
            subChild: [
                {
                    id: '02-01', name: 'Personals',
                    subChild: [
                        { id: '02-01-01', name: 'My photo.png' },
                        { id: '02-01-02', name: 'Rental document.docx' },
                        { id: '02-01-03', name: 'Pay slip.pdf' },
                    ]
                },
                {
                    id: '02-02', name: 'Projects',
                    subChild: [
                        { id: '02-02-01', name: 'ASP Application' },
                        { id: '02-02-02', name: 'TypeScript Application' },
                        { id: '02-02-03', name: 'React Application' },
                    ]
                },
                {
                    id: '02-03', name: 'Office',
                    subChild: [
                        { id: '02-03-01', name: 'Work details.docx' },
                        { id: '02-03-02', name: 'Weekly report.docx' },
                        { id: '02-03-03', name: 'Wish list.csv' },
                    ]
                },
            ]
        },
        {
            id: '03', name: 'Local Disk (E:)', icon: 'folder',
            subChild: [
                {
                    id: '03-01', name: 'Pictures',
                    subChild: [
                        { id: '03-01-01', name: 'Wind.jpg' },
                        { id: '03-01-02', name: 'Stone.jpg' },
                        { id: '03-01-03', name: 'Home.jpg' },
                    ]
                },
                {
                    id: '03-02', name: 'Documents',
                    subChild: [
                        { id: '03-02-01', name: 'Environment Pollution.docx' },
                        { id: '03-02-02', name: 'Global Warming.ppt' },
                        { id: '03-02-03', name: 'Social Network.pdf' },
                    ]
                },
                {
                    id: '03-03', name: 'Study tailwind3s',
                    subChild: [
                        { id: '03-03-01', name: 'UI-Guide.pdf' },
                        { id: '03-03-02', name: 'Tutorials.zip' },
                        { id: '03-03-03', name: 'TypeScript.7z' },
                    ]
                },
            ]
        }
    ];
    let fields = { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' };
    let allowEditing = true;
    function onNodeEdited(args) {
        let displayContent = "";
        if (args.newText.trim() == "") {
            args.cancel = true;
            displayContent = "TreeView item text should not be empty";
        }
        else if (args.newText != args.oldText) {
            displayContent = "TreeView item text edited successfully";
        }
        else {
            displayContent = "";
        }
        document.getElementById("display").innerHTML = displayContent;
    }
    return (<div className='control-pane'>
        <div className='control-section'>
        <div className='control_wrapper'>
            {/* Render TreeView */}
            <TreeViewComponent fields={fields} allowEditing={allowEditing} ref={(tree) => { treeObj = tree; }} nodeEdited={onNodeEdited.bind(this)}/>
        </div>
        <div id="display"></div>
        </div>
      </div>);
}
export default App;
ReactDOM.render(<App />, document.getElementById('sample'));
import * as ReactDOM from 'react-dom';
import * as React from 'react';
import {TreeViewComponent, NodeEditEventArgs} from '@syncfusion/ej2-react-navigations';
import {enableRipple} from '@syncfusion/ej2-base';
enableRipple(true);

function App() {

let treeObj: TreeViewComponent;

// Hierarchical data source for TreeView component
let hierarchicalData: { [key: string]: Object }[] = [
    { id: '01', name: 'Local Disk (C:)', expanded: true,
        subChild: [
            {
                id: '01-01', name: 'Program Files',
                subChild: [
                    { id: '01-01-01', name: 'Windows NT' },
                    { id: '01-01-02', name: 'Windows Mail' },
                    { id: '01-01-03', name: 'Windows Photo Viewer' },
                ]
            },
            {
                id: '01-02', name: 'Users', expanded: true,
                subChild: [
                    { id: '01-02-01', name: 'Smith' },
                    { id: '01-02-02', name: 'Public' },
                    { id: '01-02-03', name: 'Admin' },
                ]
            },
            {
                id: '01-03', name: 'Windows',
                subChild: [
                    { id: '01-03-01', name: 'Boot' },
                    { id: '01-03-02', name: 'FileManager' },
                    { id: '01-03-03', name: 'System32' },
                ]
            },
        ]
    },
    {
        id: '02', name: 'Local Disk (D:)',
        subChild: [
            {
                id: '02-01', name: 'Personals',
                subChild: [
                    { id: '02-01-01', name: 'My photo.png' },
                    { id: '02-01-02', name: 'Rental document.docx' },
                    { id: '02-01-03', name: 'Pay slip.pdf' },
                ]
            },
            {
                id: '02-02', name: 'Projects',
                subChild: [
                    { id: '02-02-01', name: 'ASP Application' },
                    { id: '02-02-02', name: 'TypeScript Application' },
                    { id: '02-02-03', name: 'React Application' },
                ]
            },
            {
                id: '02-03', name: 'Office',
                subChild: [
                    { id: '02-03-01', name: 'Work details.docx' },
                    { id: '02-03-02', name: 'Weekly report.docx' },
                    { id: '02-03-03', name: 'Wish list.csv' },
                ]
            },
        ]
    },
    {
        id: '03', name: 'Local Disk (E:)', icon: 'folder',
        subChild: [
            {
                id: '03-01', name: 'Pictures',
                subChild: [
                    { id: '03-01-01', name: 'Wind.jpg' },
                    { id: '03-01-02', name: 'Stone.jpg' },
                    { id: '03-01-03', name: 'Home.jpg' },
                ]
            },
            {
                id: '03-02', name: 'Documents',
                    subChild: [
                    { id: '03-02-01', name: 'Environment Pollution.docx' },
                    { id: '03-02-02', name: 'Global Warming.ppt' },
                    { id: '03-02-03', name: 'Social Network.pdf' },
                ]
            },
            {
                id: '03-03', name: 'Study tailwind3s',
                subChild: [
                    { id: '03-03-01', name: 'UI-Guide.pdf' },
                    { id: '03-03-02', name: 'Tutorials.zip' },
                    { id: '03-03-03', name: 'TypeScript.7z' },
                ]
            },
        ]
    }
];
let fields: object = { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' };

let allowEditing:boolean = true;

function onNodeEdited(args: NodeEditEventArgs) {
    let displayContent:string = "";
    if (args.newText.trim() == "") {
        args.cancel=true;
        displayContent = "TreeView item text should not be empty";
    }
    else if (args.newText != args.oldText) {
        displayContent = "TreeView item text edited successfully";
    } else {
        displayContent = "";
    }
    document.getElementById("display").innerHTML = displayContent;
}

    return (
      <div className = 'control-pane'>
        <div className='control-section'>
        <div className='control_wrapper'>
            {/* Render TreeView */}
            <TreeViewComponent fields={fields} allowEditing={allowEditing} ref={(tree) => { treeObj = tree}} nodeEdited={onNodeEdited.bind(this)} />
        </div>
        <div id="display"></div>
        </div>
      </div>
    )
}
export default App;
ReactDOM.render(<App />, document.getElementById('sample'));
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Syncfusion React TreeView</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for React Components" />
    <meta name="author" content="Syncfusion" />
    <link href="style.css" rel="stylesheet"/>
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/tailwind3.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/tailwind3.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-react-navigations/styles/tailwind3.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='treeparent'>
        <div id='sample'>
            <div id='loader'>Loading....</div>
        </div>
    </div>
</body>

</html>
#loader {
    color: #008cff;
    height: 40px;
    left: 45%;
    position: absolute;
    top: 45%;
    width: 30%;
}

#treeparent {
    display: block;
    max-width: 350px;
    max-height: 350px;
    margin: auto;
    overflow: auto;
    border: 1px solid #dddddd;
    border-radius: 3px;
}

 #display {
     max-width: 500px;
     margin: auto;
     padding: 10px;
}