Validate the text when renaming the tree node in Vue Treeview component

16 Mar 20238 minutes to read

You can validate the tree node text while editing using nodeEdited event of the TreeView. Following is an example that shows how to validate and prevent empty values in tree node.

<template>
  <div id="app">
    <div class="control_wrapper">
        <ejs-treeview id='treeview' :fields="fields" :allowEditing='true' :nodeEdited='nodeEdited'></ejs-treeview>
    </div>
    <div id="display"></div>
  </div>
</template>
<script>
import Vue from 'vue';
import { TreeViewPlugin } from "@syncfusion/ej2-vue-navigations";

Vue.use(TreeViewPlugin);
export default {
  data () {
    var dataSource =  [
        {
            id: 1, name: 'Discover Music', expanded: true,
            child: [
                { id: 2, name: 'Hot Singles' },
                { id: 3, name: 'Rising Artists' },
                { id: 4, name: 'Live Music' }
            ]
        },
        {
            id: 7, name: 'Sales and Events',
            child: [
                { id: 8, name: '100 Albums - $5 Each' },
                { id: 9, name: 'Hip-Hop and R&B Sale' },
                { id: 10, name: 'CD Deals' }
            ]
        },
        {
            id: 11, name: 'Categories',
            child: [
                { id: 12, name: 'Songs' },
                { id: 13, name: 'Bestselling Albums' },
                { id: 14, name: 'New Releases' },
                { id: 15, name: 'Bestselling Songs' }
            ]
        },
        {
            id: 16, name: 'MP3 Albums',
            child: [
                { id: 17, name: 'Rock' },
                { id: 18, name: 'Gospel' },
                { id: 19, name: 'Latin Music' },
                { id: 20, name: 'Jazz' }
            ]
        },
        {
            id: 21, name: 'More in Music',
            child: [
                { id: 22, name: 'Music Trade-In' },
                { id: 23, name: 'Redeem a Gift Card' },
                { id: 24, name: 'Band T-Shirts' }
            ]
        }
    ];
    return {
        fields: { dataSource: dataSource, id: 'id', text: 'name', child: 'child' },
    }
  },
  methods: {
        nodeEdited: function(args) {
            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;
            }
    }
}
</script>
<style>
  @import "../../node_modules/@syncfusion/ej2-base/styles/material.css";
  @import "../../node_modules/@syncfusion/ej2-vue-navigations/styles/material.css";
  @import "../../node_modules/@syncfusion/ej2-inputs/styles/material.css";
 .control_wrapper {
        display: block;
        max-width: 400px;
        max-height: 320px;
        margin: auto;
        overflow: auto;
        border: 1px solid #dddddd;
        border-radius: 3px;
    }
    #display {
        max-width: 500px;
        margin: auto;
        padding: 10px;
    }
    #app {
        width: 350px;
        margin: 0 auto;
    }
</style>