Multiple selection in Vue Treeview component

23 Mar 202311 minutes to read

Selection provides an interactive support and highlights the node that you select. Selection can be done through simple mouse down or keyboard interaction.

The TreeView also supports selection of multiple nodes by setting allowMultiSelection
to true.

To multi-select, press and hold CTRL key and click the desired nodes. To select range of nodes, press and hold the
SHIFT key and click the nodes.

In the following example, the allowMultiSelection property is enabled.

Multi selection is not applicable through touch interactions.

app.vue

<template>
  <div id="app">
    <div class="control_wrapper">
        <ejs-treeview id='treeview' :fields="fields" :allowMultiSelection='true'></ejs-treeview>
    </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: 'Australia', hasChild: true, expanded: true },
        { id: 2, pid: 1, name: 'New South Wales', isSelected: true },
        { id: 3, pid: 1, name: 'Victoria' },
        { id: 4, pid: 1, name: 'South Australia' },
        { id: 6, pid: 1, name: 'Western Australia', isSelected: true },
        { id: 7, name: 'Brazil', hasChild: true },
        { id: 8, pid: 7, name: 'Paraná' },
        { id: 9, pid: 7, name: 'Ceará' },
        { id: 10, pid: 7, name: 'Acre' },
        { id: 11, name: 'China', hasChild: true },
        { id: 12, pid: 11, name: 'Guangzhou' },
        { id: 13, pid: 11, name: 'Shanghai' },
        { id: 14, pid: 11, name: 'Beijing' },
        { id: 15, pid: 11, name: 'Shantou' },
        { id: 16, name: 'France', hasChild: true },
        { id: 17, pid: 16, name: 'Pays de la Loire' },
        { id: 18, pid: 16, name: 'Aquitaine' },
        { id: 19, pid: 16, name: 'Brittany' },
        { id: 20, pid: 16, name: 'Lorraine' },
        { id: 21, name: 'India', hasChild: true },
        { id: 22, pid: 21, name: 'Assam' },
        { id: 23, pid: 21, name: 'Bihar' },
        { id: 24, pid: 21, name: 'Tamil Nadu' },
        { id: 25, pid: 21, name: 'Punjab' }
    ];
    return {
        fields: { dataSource: dataSource, id: 'id', parentID: 'pid', text: 'name', hasChildren: 'hasChild', selected: 'isSelected' },
    }
  }
}
</script>
<style>
  @import "https://ej2.syncfusion.com/vue/documentation/../node_modules/@syncfusion/ej2-base/styles/material.css";
  @import "../../node_modules/@syncfusion/ej2-vue-navigations/styles/material.css";
 .control_wrapper {
        display: block;
        max-width: 350px;
        max-height: 350px;
        margin: auto;
        overflow: auto;
        border: 1px solid #dddddd;
        border-radius: 3px;
    }
</style>

Selected nodes

You can get or set the selected nodes in TreeView at initial rendering and dynamically by using the selectedNodes property. It will return the selected node’s ID as an array.

The nodeselecting event is triggered before a node is selected/unselected which can be used to prevent the selection.

The nodeSelected event is triggered once a node is successfully selected/unselected.

In the following example, New South Wales and Western Australia nodes are selected at initial rendering. When a node is selected, the selected node’s ID is displayed in alert.

app.vue

<template>
  <div id="app">
    <div class="control_wrapper">
        <ejs-treeview id='treeview' :fields="fields" :allowMultiSelection='true' :selectedNodes="selectedNodes" :nodeSelected="nodeSelected"></ejs-treeview>
    </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: 'Australia', hasChild: true, expanded: true },
        { id: 2, pid: 1, name: 'New South Wales', isSelected: true },
        { id: 3, pid: 1, name: 'Victoria' },
        { id: 4, pid: 1, name: 'South Australia' },
        { id: 6, pid: 1, name: 'Western Australia', isSelected: true },
        { id: 7, name: 'Brazil', hasChild: true },
        { id: 8, pid: 7, name: 'Paraná' },
        { id: 9, pid: 7, name: 'Ceará' },
        { id: 10, pid: 7, name: 'Acre' },
        { id: 11, name: 'China', hasChild: true },
        { id: 12, pid: 11, name: 'Guangzhou' },
        { id: 13, pid: 11, name: 'Shanghai' },
        { id: 14, pid: 11, name: 'Beijing' },
        { id: 15, pid: 11, name: 'Shantou' },
        { id: 16, name: 'France', hasChild: true },
        { id: 17, pid: 16, name: 'Pays de la Loire' },
        { id: 18, pid: 16, name: 'Aquitaine' },
        { id: 19, pid: 16, name: 'Brittany' },
        { id: 20, pid: 16, name: 'Lorraine' },
        { id: 21, name: 'India', hasChild: true },
        { id: 22, pid: 21, name: 'Assam' },
        { id: 23, pid: 21, name: 'Bihar' },
        { id: 24, pid: 21, name: 'Tamil Nadu' },
        { id: 25, pid: 21, name: 'Punjab' }
    ];
    return {
        fields: { dataSource: dataSource, id: 'id', parentID: 'pid', text: 'name', hasChildren: 'hasChild', selected: 'isSelected' },
        selectedNodes: ['2','6'],
    }
  },
  methods: {
        nodeSelected: function(args) {
           var treeObj = document.getElementById('treeview').ej2_instances[0];
            alert("The selected node's id: " + treeObj.selectedNodes); // To alert the selected node's id.
        }
    }
}
</script>
<style>
  @import "../../node_modules/@syncfusion/ej2-base/styles/material.css";
  @import "../../node_modules/@syncfusion/ej2-vue-navigations/styles/material.css";
 .control_wrapper {
        display: block;
        max-width: 350px;
        max-height: 350px;
        margin: auto;
        overflow: auto;
        border: 1px solid #dddddd;
        border-radius: 3px;
    }
</style>