Methods

|

The column's configuration or a data field for which the column should be created.

This method is intended to add columns at runtime. To add columns at design-time, use the columns array.

If stateStoring is enabled, the added column is saved in the UI component's state after the creation.

NOTE

Do not use this method to control a column's visibility; use the column's visible property instead.

addRow()

Adds an empty data row to the highest hierarchical level and switches it to the editing state.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after a new empty row is added.

Use this method if you want to add an empty row. If you need to add a row with data, do the following:

For a remote data source, insert a new row with data into it and reload the data source:

jQuery

JavaScript

$(function(){
    var treeList = $("#treeListContainer").dxTreeList({
        // ...
    }).dxTreeList("instance");
    var dataSource = treeList.getDataSource();
    dataSource.store().insert(data).then(function() {
        dataSource.reload();
    })
});

Angular

app.component.ts

app.module.ts

import { Component } from '@angular/core';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    constructor() {
        this.dataSource = new DataSource({
            // ...
        })
    }
    // ...
    insertRowRemote: function(dataObj) {
        this.dataSource.store().insert(data).then(function() {
            this.dataSource.reload();
        })
    }
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxTreeListModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxTreeListModule
    ],
    bootstrap: [AppComponent]
})
export class AppModule { }

Vue

App.vue

<template>
    <DxTreeList
        :data-source="dataSource"
    />
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import DxTreeList from 'devextreme-vue/tree-list';
import DataSource from 'devextreme/data/data_source';

const ds = new DataSource({
    // ...
});

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            dataSource: ds
        }
    },
    methods: {
        insertRowRemote: function(dataObj) {
            ds.store().insert(dataObj).then(() => ds.reload());
        }
    }
}
</script>

React

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';
import DataSource from 'devextreme/data/data_source';

const ds = new DataSource({
    // ...
});

class App extends React.Component {
    insertRowRemote(dataObj) {
        ds.store().insert(dataObj).then(() => ds.reload());
    }
    render() {
        return (
            <TreeList
                dataSource={ds}
            />
        );
    }
}
export default App;

For a local data source, push a new row into it.

jQuery

JavaScript

$(function(){
    var treeList = $("#treeListContainer").dxTreeList({
        // ...
    }).dxTreeList("instance");

var dataSource = treeList.getDataSource();

dataSource.store().push([
    { type: "insert", data: data }
])

});

Angular

app.component.ts

app.module.ts

import { Component } from '@angular/core';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    constructor() {
        this.dataSource = new DataSource({
            // ...
        })
    }
    // ...
    insertRowLocal: function(dataObj) {
        this.dataSource.store().push([
            { type: "insert", data: dataObj }
        ])
    }
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxTreeListModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxTreeListModule
    ],
    bootstrap: [AppComponent]
})
export class AppModule { }

Vue

App.vue

<template>
    <DxTreeList
        :data-source="dataSource"
    />
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import DxTreeList from 'devextreme-vue/tree-list';
import DataSource from 'devextreme/data/data_source';

const ds = new DataSource({
    // ...
});

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            dataSource: ds
        }
    },
    methods: {
        insertRowLocal: function(dataObj) {
            ds.store().push([
                { type: "insert", data: dataObj }
            ]);
        }
    }
}
</script>

React

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';
import DataSource from 'devextreme/data/data_source';

const ds = new DataSource({
    // ...
});

class App extends React.Component {
    insertRowLocal(dataObj) {
        ds.store().push([
            { type: "insert", data: dataObj }
        ]);
    }
    render() {
        return (
            <TreeList
                dataSource={ds}
            />
        );
    }
}
export default App;

This method works only when paging.enabled is false or when dataSource.reshapeOnPush is true and remoteOperations is false.

addRow(parentId)

Adds an empty data row to a specified parent row.

Parameters:

parentId: any

The parent row's ID.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after a new empty row is added.

beginCustomLoading(messageText)

Shows the load panel.

Parameters:

messageText:

The text for the load panel to display.

Normally, the load panel is invoked automatically while the UI component is busy rendering or loading data. Additionally, you can invoke it by calling this method. If you call it without the argument, the load panel displays text specified by the loadPanel.text property. To specify the appearance of the load panel, use the loadPanel object. Once invoked from code, the load panel will not hide until you call the endCustomLoading() method.

NOTE

The load panel invoked from code does not replace the automatically invoked load panel. This circumstance might lead to a situation where the load panel invoked from code suddenly changes its text because it was overridden by the automatically invoked load panel. Therefore, be mindful when invoking the load panel with different text.

beginUpdate()

Prevents the UI component from refreshing until the endUpdate() method is called.

The beginUpdate() and endUpdate() methods prevent the UI component from excessive updates when you are changing multiple UI component settings at once. After the beginUpdate() method is called, the UI component does not update its UI until the endUpdate() method is called.

byKey(key)

Gets a data object with a specific key.

Parameters:

key:

|

|

The data object's key.

Return Value:

Promise<Object> (jQuery or native)

A Promise that is resolved after the data object is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

The following code shows how to get a data object whose key is 15.

JavaScript

widgetInstance.byKey(15).done(function(dataObject) {
        // process "dataObject"
    }).fail(function(error) {
        // handle error
    });

cancelEditData()

Discards changes that a user made to data.

View Demo

cellValue(rowIndex, dataField)

Gets the value of a cell with a specific row index and a data field, column caption or name.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

dataField:

The data field, caption, or unique name of the column to which the cell belongs.

Return Value: any

The cell's value.

cellValue(rowIndex, dataField, value)

Sets a new value to a cell with a specific row index and a data field, column caption or name.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

dataField:

The data field, caption, or unique name of the column to which the cell belongs.

value: any

The cell's new value.

Call saveEditData() after this method to save the changes:

jQuery

JavaScript

var treeList = $("#treeListContainer").dxTreeList("instance");
treeList.cellValue(0, "Position", "CEO");
treeList.saveEditData();

Angular

TypeScript

import { ..., ViewChild } from "@angular/core";
import { DxTreeListModule, DxTreeListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxTreeListComponent, { static: false }) treeList: DxTreeListComponent;
    // Prior to Angular 8
    // @ViewChild(DxTreeListComponent) treeList: DxTreeListComponent;
    updateCell(rowIndex, dataField, value) {
        this.treeList.instance.cellValue(rowIndex, dataField, value);
        this.treeList.instance.saveEditData();
    }
}
@NgModule({
    imports: [
        // ...
        DxTreeListModule
    ],
    // ...
})

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRefKey"> 
    </DxTreeList>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import { DxTreeList } from 'devextreme-vue/tree-list';

const treeListRefKey = 'my-tree-list';

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            treeListRefKey
        };
    },
    methods: {
        updateCell(rowIndex, dataField, value) {
            this.treeList.cellValue(rowIndex, dataField, value);
            this.treeList.saveEditData();
        }
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRefKey].instance;
        }
    }
}
</script>

React

App.js

import React, { useRef } from 'react';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';

export default function App() {
    const treeList = useRef(null);
    const updateCell = (rowIndex, dataField, value) => {
        treeList.current.instance.cellValue(rowIndex, dataField, value);
        treeList.current.instance.saveEditData();
    };
    return (
        <TreeList ...
            ref={treeList}>
        </TreeList>
    );
}

cellValue(rowIndex, visibleColumnIndex)

Gets the value of a cell with specific row and column indexes.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

visibleColumnIndex:

The visible index of the column to which the cell belongs.

Return Value: any

The cell's value.

cellValue(rowIndex, visibleColumnIndex, value)

Sets a new value to a cell with specific row and column indexes.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

visibleColumnIndex:

The visible index of the column to which the cell belongs.

value: any

The cell's new value.

Call saveEditData() after this method to save the changes:

jQuery

JavaScript

var treeList = $("#treeListContainer").dxTreeList("instance");
treeList.cellValue(0, 1, "newValue");
treeList.saveEditData();

Angular

TypeScript

import { ..., ViewChild } from "@angular/core";
import { DxTreeListModule, DxTreeListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxTreeListComponent, { static: false }) treeList: DxTreeListComponent;
    // Prior to Angular 8
    // @ViewChild(DxTreeListComponent) treeList: DxTreeListComponent;
    updateCell(rowIndex, columnIndex, value) {
        this.treeList.instance.cellValue(rowIndex, columnIndex, value);
        this.treeList.instance.saveEditData();
    }
}
@NgModule({
    imports: [
        // ...
        DxTreeListModule
    ],
    // ...
})

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRefKey"> 
    </DxTreeList>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import { DxTreeList } from 'devextreme-vue/tree-list';

const treeListRefKey = 'my-tree-list';

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            treeListRefKey
        };
    },
    methods: {
        updateCell(rowIndex, columnIndex, value) {
            this.treeList.cellValue(rowIndex, columnIndex, value);
            this.treeList.saveEditData();
        }
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRefKey].instance;
        }
    }
}
</script>

React

App.js

import React, { useRef } from 'react';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';

export default function App() {
    const treeList = useRef(null);
    const updateCell = (rowIndex, columnIndex, value) => {
        treeList.current.instance.cellValue(rowIndex, columnIndex, value);
        treeList.current.instance.saveEditData();
    };
    return (
        <TreeList ...
            ref={treeList}>
        </TreeList>
    );
}

clearFilter()

Clears all filters applied to UI component rows.

clearFilter(filterName)

Clears all row filters of a specific type.

Parameters:

filterName:

The filter type.

The method's parameter specifies what type of filter should be cleared. This parameter can have one of the following values:

"row"
Clears the filter row.
"header"
Clears the header filter.
"filterValue"
Clears the filter builder and the synchronized filtering UI elements.
"search"
Clears the search panel.
"dataSource"
Clears the data source filter defined in the configuration or applied by the filter(filterExpr) method.

clearSelection()

Clears selection of all rows on all pages.

clearSorting()

Clears sorting settings of all columns at once.

closeEditCell()

Switches the cell being edited back to the normal state. Takes effect only if editing.mode is batch and showEditorAlways is false.

collapseAdaptiveDetailRow()

Collapses the currently expanded adaptive detail row (if there is one).

collapseRow(key)

Collapses a row with a specific key.

Parameters:

key: any

The row's key.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after the row is collapsed. It is a native Promise or a jQuery.Promise when you use jQuery.

columnCount()

Gets the data column count. Includes visible and hidden columns, excludes command columns.

Return Value:

The data column count.

columnOption(id)

Gets all properties of a column with a specific identifier.

Parameters:

id:

|

The column's index, data field, caption, type, or unique name.

Return Value:

The column's properties.

This method gets the properties of the first column found by either of the below:

Name
The unique name of the column.
Column Index
The index of the column in the columns array.
Data Field
The name of the data source field assigned to the column.
Caption
The text displayed in the column header.
Service String
A string that matches the following format: "optionName:value", where optionName is one of the column properties. For example, the following string corresponds to the command column: "type:buttons".

columnOption(id, optionName)

Gets the value of a single column property.

Parameters:

id:

|

The column's index, data field, caption, type, or unique name. Refer to columnOption(id) for details.

optionName:

The property's name.

Return Value: any

The property's value.

columnOption(id, optionName, optionValue)

Updates the value of a single column property.

Parameters:

id:

|

The column's index, data field, caption, type, or unique name. Refer to columnOption(id) for details.

optionName:

The property's name.

optionValue: any

The property's new value.

columnOption(id, options)

Updates the values of several column properties.

Parameters:

id:

|

The column's index, data field, caption, type, or unique name. Refer to columnOption(id) for details.

options:

The properties with their new values.

defaultOptions(rule)

Specifies the device-dependent default configuration properties for this component.

Parameters:

rule:

The component's default device properties.

Object structure:

Name	Type	Description
device	Device \| Array<Device> \| Function	Device parameters. When specifying a function, get information about the current device from the argument. Return true if the properties should be applied to the device.
options	Object	Options to be applied.

Name

Type

Description

device

Device

|

Array<Device>

|

Device parameters.
When specifying a function, get information about the current device from the argument. Return true if the properties should be applied to the device.

options

Options to be applied.

defaultOptions is a static method that the UI component class supports. The following code demonstrates how to specify default properties for all instances of the TreeList UI component in an application executed on the desktop.

jQuery

JavaScript

DevExpress.ui.dxTreeList.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the TreeList properties
    }
});

Angular

TypeScript

import TreeList from "devextreme/ui/tree_list";
// ...
export class AppComponent {
    constructor () {
        TreeList.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the TreeList properties
            }
        });
    }
}

Vue

<template>
    <div>
        <DxTreeList id="treeList1" />
        <DxTreeList id="treeList2" />
    </div>
</template>
<script>
import DxTreeList from "devextreme-vue/tree-list";
import TreeList from "devextreme/ui/tree_list";

TreeList.defaultOptions({
    device: { deviceType: "desktop" },
    options: {
        // Here go the TreeList properties
    }
});

export default {
    components: {
        DxTreeList
    }
}
</script>

React

import React from "react";
import dxTreeList from "devextreme/ui/tree_list";
import TreeList from "devextreme-react/tree-list";

class App extends React.Component {
    render () {
        dxTreeList.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the TreeList properties
            }
        })
        return (
            <div>
                <TreeList id="treeList1" />
                <TreeList id="treeList2" />
            </div>
        )
    }
}

export default App;

deleteColumn(id)

Removes a column.

Parameters:

id:

|

The column's index, data field, caption or unique name.

This method removes the first column found by either of the below:

Name
The unique name of the column.
Column Index
The index of the column in the columns array.
Data Field
The name of the data source field assigned to the column.
Caption
The text displayed in the column header.

deleteRow(rowIndex)

Removes a row with a specific index.

Parameters:

rowIndex:

The row's index. Refer to Column and Row Indexes for more information.

NOTE

You cannot call this method to delete a row if this row is being edited in row or form editing mode. In these modes, you can modify only one row at a time and you should finish the row edit to call this method.

deselectAll()

Clears the selection of all rows on all pages or the currently rendered page only.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after the selection is cleared. It is a native Promise or a jQuery.Promise when you use jQuery.

deselectRows(keys)

Cancels the selection of rows with specific keys.

Parameters:

keys:

Array<any>

The row keys.

Return Value:

Promise<any> (jQuery or native)

A Promise that is resolved after selection is cleared. It is a native Promise or a jQuery.Promise when you use jQuery.

dispose()

Disposes of all the resources allocated to the TreeList instance.

After calling this method, remove the DOM element associated with the UI component:

JavaScript

$("#myTreeList").dxTreeList("dispose");
$("#myTreeList").remove();

Use this method only if the UI component was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:

Angular

app.component.html

<dx-tree-list ...
    *ngIf="condition">
</dx-tree-list>

Vue

App.vue

<template>
    <DxTreeList ...
        v-if="condition">
    </DxTreeList>
</template>

<script>
import DxTreeList from 'devextreme-vue/tree-list';

export default {
    components: {
        DxTreeList
    }
}
</script>

React

App.js

import React from 'react';

import TreeList from 'devextreme-react/tree-list';

function DxTreeList(props) {
    if (!props.shouldRender) {
        return null;
    }

    return (
        <TreeList ... >    
        </TreeList>
    );
}

class App extends React.Component {
    render() {
        return (
            <DxTreeList shouldRender="condition" />
        );
    }
}
export default App;

editCell(rowIndex, dataField)

Switches a cell with a specific row index and a data field to the editing state. Takes effect only if the editing mode is "batch" or "cell".

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

dataField:

The name of the data field in the data source.

editCell(rowIndex, visibleColumnIndex)

Switches a cell with specific row and column indexes to the editing state. Takes effect only if the editing mode is "batch" or "cell".

Parameters:

rowIndex:

A Promise that is resolved after the row is expanded. It is a native Promise or a jQuery.Promise when you use jQuery.

filter()

Gets a filter expression applied to the UI component's data source using the filter(filterExpr) method and the DataSource's filter property.

Return Value: any

filter(filterExpr)

Applies a filter to the UI component's data source.

Parameters:

filterExpr: any

Pass an array with the following members to this method:

The data source field by which data items are filtered.
The comparison operator. The following operators are available: "=", "<>", ">", ">=", "<", "<=", "startswith", "endswith", "contains", "notcontains".
The value with which data source field values should be compared.

A function to be executed; return false to stop traversing deeper.

getCellElement(rowIndex, dataField)

Gets a cell with a specific row index and a data field, column caption or name.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

dataField:

The data field, caption, or unique name of the column to which the cell belongs.

Return Value:

HTMLElement or jQuery

| undefined

The cell's container. It is an HTML Element or a jQuery Element when you use jQuery.

If the specified row or data field does not exist, the method returns undefined.

getCellElement(rowIndex, visibleColumnIndex)

Gets a cell with specific row and column indexes.

Parameters:

rowIndex:

The index of the row to which the cell belongs. Refer to Column and Row Indexes for more information.

visibleColumnIndex:

The visible index of the column to which the cell belongs.

Return Value:

HTMLElement or jQuery

| undefined

The cell's container. It is an HTML Element or a jQuery Element when you use jQuery.

If the specified row or column does not exist, the method returns undefined.

getCombinedFilter()

Gets the total filter that combines all the filters applied.

Return Value: any

Use this method to get the total filter. This filter combines filters applied using filtering UI elements and the filter(filterExpr) method. Note that the total filter contains getters. To get the total filter containing data fields, call the getCombinedFilter(returnDataField) method.

getCombinedFilter(returnDataField)

Gets the total filter that combines all the filters applied.

Parameters:

returnDataField:

Specifies whether the total filter should contain data fields instead of getters.

Return Value: any

Use this method to get the total filter. This filter combines filters applied using filtering UI elements and the filter(filterExpr) method.

getDataSource()

Gets the DataSource instance.

Return Value:

DataSource

The DataSource instance.

NOTE

This method returns the DataSource instance even if the UI component's dataSource property was given a simple array.

getInstance(element)

Gets the instance of a UI component found using its DOM node.

Parameters:

element:

Element

|

jQuery

The UI component's container.

Return Value:

The UI component's instance.

getInstance is a static method that the UI component class supports. The following code demonstrates how to get the TreeList instance found in an element with the myTreeList ID:

// Modular approach
import TreeList from "devextreme/ui/tree_list";
...
let element = document.getElementById("myTreeList");
let instance = TreeList.getInstance(element) as TreeList;

// Non-modular approach
let element = document.getElementById("myTreeList");
let instance = DevExpress.ui.dxTreeList.getInstance(element);

getScrollable()

Gets the instance of the UI component's scrollable part.

Return Value:

Scrollable

The scrollable part's instance.

For information on API members of the scrollable part, refer to the ScrollView section, but bear in mind that several members described there are unavailable. Those are the following.

Properties:

pullingDownText
pulledDownText
refreshingText
reachBottomText
onPullDown
onReachBottom

Methods:

release(preventScrollBottom)
refresh()

getSelectedRowKeys()

Gets the keys of the rows selected explicitly via the API or via a click or tap.

Return Value:

Array<any>

Keys of selected rows. The keys are stored in the order the user selects rows.

getSelectedRowKeys(mode)

Gets the selected rows' keys.

Parameters:

mode:

"all", "excludeRecursive", or "leavesOnly".

Return Value:

Array<any>

Keys of selected rows. The keys are stored in the order the user selects rows.

Below is an example of a TreeList with several selected rows:

Selection in the DevExtreme TreeList

The getSelectedRowKeys(mode) method called for this TreeList returns different results depending on the mode argument:

"all"
Returns all the selected rows' keys.

getSelectedRowKeys("all") // returns [2, 5, 8, 9, 6, 10, 4]

"excludeRecursive"
Excludes recursively selected rows' keys.

getSelectedRowKeys("excludeRecursive") // returns [2, 6, 10, 4]

"leavesOnly"
Returns only leaves' keys.

getSelectedRowKeys("leavesOnly") // returns [8, 9, 6, 10, 4]

getSelectedRowsData()

Gets the data objects of the rows selected explicitly via the API or via a click or tap.

Return Value:

Array<any>

The selected rows' data objects.
The objects are not processed by the DataSource and have the same order in which the rows were selected.

jQuery

index.js

var treeList = $("#treeListContainer").dxTreeList("instance");

var selectedRowsData = treeList.getSelectedRowsData();

Angular

app.component.ts

app.component.html

app.module.ts

import { Component, ViewChild } from '@angular/core';
import { DxTreeListComponent } from 'devextreme-angular';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    @ViewChild('treeListRef', { static: false }) treeList: DxTreeListComponent;
    // Prior to Angular 8
    // @ViewChild('treeListRef') treeList: DxTreeListComponent;

    selectedRowsData = [];

    getSelectedData() {
        this.selectedRowsData = this.treeList.instance.getSelectedRowsData();
    }
}

<dx-tree-list ...
    #treeListRef
></dx-tree-list>

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxTreeListModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxTreeListModule
    ],
    providers: [ ],
    bootstrap: [AppComponent]
})
export class AppModule { }

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRef">
    </DxTreeList>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import DxTreeList from 'devextreme-vue/tree-list';

const treeListRef = 'treeList';

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            treeListRef,
            selectedRowsData: []
        }
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRef].instance;
        }
    },
    methods: {
        getSelectedData() {
            this.selectedRowsData = this.treeList.getSelectedRowsData();
        }
    }
}
</script>

React

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';

class App extends React.Component {
    constructor(props) {
        super(props);

        this.treeListRef = React.createRef();

        this.selectedRowsData = [];

        this.getSelectedData = () => {
            this.selectedRowsData = this.treeList.getSelectedRowsData();
        }
    }

    get treeList() {
        return this.treeListRef.current.instance;
    }

    render() {
        return (
            <TreeList ...
                ref={this.treeListRef}>
            </TreeList>
        );
    }
}
export default App;

ASP.NET MVC Controls

Razor C#

@(Html.DevExtreme().TreeList()
    .ID("treeList")
    @* ... *@
)

<script type="text/javascript">
    function getSelectedData() {
        var treeList = $("#treeList").dxTreeList("instance");
        var selectedRowsData = treeList.getSelectedRowsData();
        // ...
    }
</script>

NOTE

Calculated values cannot be obtained because this method gets data objects from the data source.

getSelectedRowsData(mode)

Gets the selected rows' data objects.

Parameters:

mode:

"all", "excludeRecursive", or "leavesOnly".

Return Value:

Array<any>

The selected rows' data objects.
The objects are not processed by the DataSource and have the same order in which the rows were selected.

Below is an example of a TreeList with several selected rows:

Selection in the DevExtreme TreeList

The getSelectedRowsData(mode) method called for this TreeList returns different results depending on the mode argument:

"all"
Returns all the selected rows' data objects.

getSelectedRowsData("all") // returns data objects with the following keys: 2, 5, 8, 9, 6, 10, and 4

"excludeRecursive"
Excludes recursively selected rows' data objects.

getSelectedRowsData("excludeRecursive") // returns data objects with the following keys: 2, 6, 10, and 4

"leavesOnly"
Returns only leaves' data objects.

getSelectedRowsData("leavesOnly") // returns data objects with the following keys: 8, 9, 6, 10, and 4

jQuery

index.js

var treeList = $("#treeListContainer").dxTreeList("instance");

var selectedRowsData = treeList.getSelectedRowsData("leavesOnly");

Angular

app.component.ts

app.component.html

app.module.ts

import { Component, ViewChild } from '@angular/core';
import { DxTreeListComponent } from 'devextreme-angular';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    @ViewChild('treeListRef', { static: false }) treeList: DxTreeListComponent;
    // Prior to Angular 8
    // @ViewChild('treeListRef') treeList: DxTreeListComponent;

    selectedRowsData = [];

    getSelectedData() {
        this.selectedRowsData = this.treeList.instance.getSelectedRowsData('leavesOnly');
    }
}

<dx-tree-list ...
    #treeListRef
></dx-tree-list>

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxTreeListModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxTreeListModule
    ],
    providers: [ ],
    bootstrap: [AppComponent]
})
export class AppModule { }

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRef">
    </DxTreeList>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import DxTreeList from 'devextreme-vue/tree-list';

const treeListRef = 'treeList';

export default {
    components: {
        DxTreeList
    },
    data() {
        return {
            treeListRef,
            selectedRowsData: []
        }
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRef].instance;
        }
    },
    methods: {
        getSelectedData() {
            this.selectedRowsData = this.treeList.getSelectedRowsData('leavesOnly');
        }
    }
}
</script>

React

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import TreeList from 'devextreme-react/tree-list';

class App extends React.Component {
    constructor(props) {
        super(props);

        this.treeListRef = React.createRef();

        this.selectedRowsData = [];

        this.getSelectedData = () => {
            this.selectedRowsData = this.treeList.getSelectedRowsData('leavesOnly');
        }
    }

    get treeList() {
        return this.treeListRef.current.instance;
    }

    render() {
        return (
            <TreeList ...
                ref={this.treeListRef}>
            </TreeList>
        );
    }
}
export default App;

ASP.NET MVC Controls

Razor C#

@(Html.DevExtreme().TreeList()
    .ID("treeList")
    @* ... *@
)

<script type="text/javascript">
    function getSelectedData() {
        var treeList = $("#treeList").dxTreeList("instance");
        var selectedRowsData = treeList.getSelectedRowsData();
        // ...
    }
</script>

NOTE

Calculated values cannot be obtained because this method gets data objects from the data source.

getVisibleColumnIndex(id)

Gets the index of a visible column.

Parameters:

id:

|

The column's index, data field, caption, type, or unique name. Refer to columnOption(id) for details.

Return Value:

The column's index.

getVisibleColumns()

Gets all visible columns.

Return Value:

Array<TreeList Column>

Visible columns; may include command columns.

getVisibleColumns(headerLevel)

Gets all visible columns at a specific hierarchical level of column headers. Use it to access banded columns.

Parameters:

headerLevel:

The column headers' level.

Return Value:

Array<TreeList Column>

Visible columns; may include command columns.

getVisibleRows()

Gets currently rendered rows.

Return Value:

Array<TreeList Row>

Currently rendered rows.

hasEditData()

Checks whether the UI component has unsaved changes.

Return Value:

true if the UI component has unsaved changes; otherwise - false.

hideColumnChooser()

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after data is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

loadDescendants(keys)

Loads a specific node's descendants. Takes effect only if data has the plain structure and remoteOperations | filtering is true.

Parameters:

keys:

Array<any>

Node keys.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after data is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

loadDescendants(keys, childrenOnly)

Loads all or only direct descendants of specific nodes. Takes effect only if data has the plain structure and remoteOperations | filtering is true.

Parameters:

keys:

Array<any>

Node keys.

childrenOnly:

Pass true to load only children, false to load all the specified node's descendants.
false by default.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after data is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

navigateToRow(key)

Navigates to a row with the specified key.

Parameters:

key: any

The row's key.

This method performs the following actions:

Switches the UI component to the data page that contains the specified row.
Expands groups in which the row is nested.
Scrolls the UI component to display the row (if the row is outside the viewport).

The following requirements apply when you use this method:

The UI component's keyExpr or the store's key property should be specified.
Rows should be initially sorted by keys. You can sort them on the server or use a column's sortOrder or the DataSource's sort property to sort the rows on the client.

off(eventName)

Detaches all event handlers from a single event.

Parameters:

eventName:

The event's name.

Return Value:

The object for which this method is called.

off(eventName, eventHandler)

Detaches a particular event handler from a single event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

on(eventName, eventHandler)

Subscribes to an event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

Use this method to subscribe to one of the events listed in the Events section.

on(events)

Subscribes to events.

Parameters:

events:

Events with their handlers: { "eventName1": handler1, "eventName2": handler2, ...}

Return Value:

The object for which this method is called.

Use this method to subscribe to several events with one method call. Available events are listed in the Events section.

option()

Gets all UI component properties.

Return Value:

The UI component's properties.

option(optionName)

Gets the value of a single property.

Parameters:

optionName:

The property's name or full path.

Return Value: any

This property's value.

option(optionName, optionValue)

Updates the value of a single property.

Parameters:

optionName:

The property's name or full path.

optionValue: any

This property's new value.

option(options)

Updates the values of several properties.

Parameters:

options:

Options with their new values.

pageCount()

Gets the total page count.

Return Value:

The total page count.

pageIndex()

Gets the current page index.

Return Value:

The current page index.

When the scrolling mode is "virtual", this method returns the index of the page whose row is shown first in the UI component.

pageIndex(newIndex)

Switches the UI component to a specific page using a zero-based index.

Parameters:

newIndex:

The zero-based page index.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after the page is shown. It is a native Promise or a jQuery.Promise when you use jQuery.

pageSize()

Gets the current page size.

Return Value:

The current page size.

pageSize(value)

Sets the page size.

Parameters:

value:

The page size.

refresh()

Reloads data and repaints the UI component.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after data is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

The UI component cannot track changes a third party makes in the data source. To update data in the UI component in this case, call the refresh() method. Data sources of lookup columns are updated with the main data source.

The following code shows how to call this method:

jQuery

index.js

var treeList = $("#treeListContainer").dxTreeList("instance");
treeList.refresh()
    .done(function() {
        // ...
    })
    .fail(function(error) {
        // ...
    });

Angular

app.component.html

<dx-tree-list #treeListVar ... >
    <!-- ... -->
</dx-tree-list>

app.component.ts

import { Component, ViewChild } from '@angular/core';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    @ViewChild('treeListVar', { static: false }) treeList: DxTreeListComponent;
    // Prior to Angular 8
    // @ViewChild('treeListVar') treeList: DxTreeListComponent;

    refreshTreeList() {
        this.treeList.instance.refresh()
            .then(function() {
                // ...
            })
            .catch(function(error) {
                // ...
            });
    }
}

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRefKey">
        <!-- ... -->
    </DxTreeList>
</template>
<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import { DxTreeList, /* ... */ } from 'devextreme-vue/tree-list';

export default {
    components: {
        DxTreeList,
        // ...
    },
    data() {
        return {
            treeListRefKey: 'treeList'
        };
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRefKey].instance;
        }
    },
    methods: {
        refreshTreeList() {
            this.treeList.refresh()
                .then(function() {
                    // ...
                })
                .catch(function(error) {
                    // ...
                });
        }
    }
};
</script>

React

App.js

import React from 'react';

import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import { TreeList, /* ... */ } from 'devextreme-react/tree-list';

class App extends React.Component {
    render() {
        return (
            <TreeList ...
                ref={ref => this.treeList = ref}>
                {/* ... */}
            </TreeList>
        );
    }
    refreshTreeList() {
        this.treeList.instance.refresh()
            .then(function() {
                // ...
            })
            .catch(function(error) {
                // ...
            });
    }
}
export default App;

ASP.NET MVC Controls

Razor C#

@(Html.DevExtreme().TreeList()
    .ID("treeListContainer")
    // ...
)
<script type="text/javascript">
    function refreshTreeList() {
        var treeList = $("#treeListContainer").dxTreeList("instance");
        treeList.refresh()
            .done(function() {
                // ...
            })
            .fail(function(error) {
                // ...
            });
    }
</script>

NOTE

Calling the refresh() method ends the editing process. In batch editing mode, changes are saved in a buffer before they are saved to the data source. In other modes, all unsaved changes are discarded.

refresh(changesOnly)

Reloads data and repaints the UI component or elements whose data changed.

Parameters:

changesOnly:

Pass true to repaint elements whose data changed; false to repaint the entire UI component.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after data is loaded. It is a native Promise or a jQuery.Promise when you use jQuery.

Main article: refresh()

View Demo

repaint()

Repaints the UI component without reloading data. Call it to update the UI component's markup.

repaintRows(rowIndexes)

Repaints specific rows.

Parameters:

rowIndexes:

Array<Number>

Row indexes. Refer to Column and Row Indexes for more information.

This method updates the row objects and their visual representation.

resetOption(optionName)

Resets an property to its default value.

Parameters:

optionName:

An property's name.

saveEditData()

Saves changes that a user made to data.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after changes are saved in the data source. It is a native Promise or a jQuery.Promise when you use jQuery.

searchByText(text)

Seeks a search string in the columns whose allowSearch property is true.

Parameters:

text:

A search string. Pass an empty string to clear search results.

selectAll()

Selects all rows.

Return Value:

Promise<void> (jQuery or native)

A Promise that is resolved after all rows are selected. It is a native Promise or a jQuery.Promise when you use jQuery.

If a filter is applied, this method selects only those rows that meet the filtering conditions.

selectRows(keys, preserve)

Selects rows with specific keys.

Parameters:

keys:

Array<any>

The row keys.

preserve:

Specifies whether previously selected rows should stay selected.

Return Value:

Promise<any> (jQuery or native)

A Promise that is resolved after the rows are selected. It is a native Promise or a jQuery.Promise when you use jQuery.

By default, this method call clears selection of previously selected rows. To keep these rows selected, call this method with true as the second argument.

JavaScript

widgetInstance.selectRows([5, 10, 12], true);

selectRowsByIndexes(indexes)

Selects rows with specific indexes.

Parameters:

indexes:

Array<Number>

The row indexes.

Return Value:

Promise<any> (jQuery or native)

A Promise that is resolved after the rows are selected. It is a native Promise or a jQuery.Promise when you use jQuery.

This method has the following specifics:

A call of this method clears selection of all previously selected rows.
When calculating row indexes, the UI component ignores the hierarchy of rows.

showColumnChooser()

Shows the column chooser.

state()

Gets the current UI component state.

Return Value:

The current UI component state.

The following example shows how to save the UI component state in the local storage and load it from there:

jQuery

JavaScript

$(function () {
    const treeList = $("#treeListContainer").dxTreeList({ 
        // ...
    }).dxTreeList;
    $("#save").dxButton({
        text: "Save State",
        onClick: function() {
            const state = treeList.state();
            // Saves the state in the local storage
            localStorage.setItem("treeListState", JSON.stringify(state));
        }
    });
    $("#load").dxButton({
        text: "Load State",
        onClick: function() {
            const state = JSON.parse(localStorage.getItem("treeListState"));
            treeList.state(state);
        }
    });
});

Angular

TypeScript

HTML

import { Component, ViewChild } from "@angular/core";
import { 
    DxTreeListModule, 
    DxButtonModule, 
    DxTreeListComponent 
} from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxTreeListComponent, { static: false }) treeList: DxTreeListComponent
    // Prior to Angular 8
    // @ViewChild(DxTreeListComponent) treeList: DxTreeListComponent
    saveState() {
        const state = this.treeList.instance.state();
        // Saves the state in the local storage
        localStorage.setItem("treeListState", JSON.stringify(state));
    }
    loadState() {
        const state = JSON.parse(localStorage.getItem("treeListState"));
        this.treeList.instance.state(state);
    }
}
@NgModule({
    imports: [
        DxTreeListModule,
        DxButtonModule,
        // ...
    ],
    // ...
})

<dx-tree-list ...>
</dx-tree-list>
<dx-button
    text="Save State"
    (onClick)="saveState()">
</dx-button>
<dx-button
    text="Load State"
    (onClick)="loadState()">
</dx-button>

Vue

App.vue

<template>
    <DxTreeList ...
        :ref="treeListRefKey">
    </DxTreeList>
    <DxButton
        text="Save State"
        @click="saveState"
    />
    <DxButton
        text="Load State"
        @click="loadState"
    />
</template>

<script>
import 'devextreme/dist/css/dx.light.css';

import DxTreeList, {
    // ...
} from 'devextreme-vue/tree-list';
import DxButton from 'devextreme-vue/button';

const treeListRefKey = "my-tree-list";

export default {
    components: {
        DxTreeList,
        // ...
        DxButton
    },
    data() {
        return {
            treeListRefKey
        }
    },
    methods: {
        saveState() {
            const state = this.treeList.state();
            // Saves the state in the local storage
            localStorage.setItem("treeListState", JSON.stringify(state));
        },
        loadState() {
            const state = JSON.parse(localStorage.getItem("treeListState"));
            this.treeList.state(state);
        }
    },
    computed: {
        treeList: function() {
            return this.$refs[treeListRefKey].instance;
        }
    }
}
</script>

React

App.js

import React, { useRef } from 'react';
import 'devextreme/dist/css/dx.light.css';

import TreeList, {
    // ...
} from 'devextreme-react/tree-list';
import Button from 'devextreme-react/button';

export default function App() {
    const treeList = useRef(null);
    const saveState = () => {
        const state = treeList.current.instance.state();
        // Saves the state in the local storage
        localStorage.setItem("treeListState", JSON.stringify(state));
    };
    const loadState = () => {
        const state = JSON.parse(localStorage.getItem("treeListState"));
        treeList.current.instance.state(state);
    };
    return (
        <React.Fragment>
            <TreeList ...
                ref={treeList}>
            </TreeList>
            <Button
                text="Save State"
                onClick={saveState}
            />
            <Button
                text="Load State"
                onClick={loadState}
            />
        </React.Fragment>
    );
}

state(state)

Sets the UI component state.

Parameters:

state:

The UI component's state to be set. Pass null to reset the state to default.

After the state is set, the TreeList reloads data to apply sorting, filtering, and other data processing settings.

Refer to the state() method description for an example of how to work with the UI component state.

undeleteRow(rowIndex)

Recovers a row deleted in batch editing mode.

Parameters:

rowIndex: