Angular Common - Utils - ui - themes

An object that serves as a namespace for the methods that work with DevExtreme CSS Themes.

import ui.themes from "devextreme-angular/ui/themes"

current()

Gets the current theme's name.

Return Value:

String

The current theme's name.

current(themeName)

Sets a theme with a specific name.

Parameters:
themeName:

String

The theme's name.

The theme name passed as a parameter should be the value of the data-theme attribute used within the rel="dx-theme" links to the theme. For instance, if you have links to two of your themes...

HTML
  • <link rel="dx-theme" data-theme="generic.dark" href="css/mytheme-dark.css" data-active="true">
  • <link rel="dx-theme" data-theme="generic.light" href="css/mytheme-light.css" data-active="false">

... you can switch between them as shown in the code below. Note that you should specify a callback function that repaints all UI components after the theme has been loaded using the ready(callback) method.

TypeScript
  • import themes from "devextreme/ui/themes";
  • import { Component, ViewChild } from "@angular/core";
  • import { DxDataGridComponent, DxButtonComponent } from "devextreme-angular";
  •  
  • @Component({
  • selector: 'my-app',
  • template: `
  • <dx-data-grid [dataSource]="dataSource"></dx-data-grid>
  • <dx-button text="Change Theme" (onClick)="changeTheme()"></dx-button>
  • `
  • })
  •  
  • export class AppComponent {
  • @ViewChild(DxDataGridComponent, { static: false }) dataGrid: DxDataGridComponent;
  • @ViewChild(DxButtonComponent, { static: false }) button: DxButtonComponent;
  • // Prior to Angular 8
  • // @ViewChild(DxDataGridComponent) dataGrid: DxDataGridComponent;
  • // @ViewChild(DxButtonComponent) button: DxButtonComponent;
  •  
  • changeTheme() {
  • themes.ready(() => {
  • this.dataGrid.instance.repaint();
  • this.button.instance.repaint();
  • });
  • themes.current('generic.light');
  • // themes.current('generic.dark');
  • }
  • }

Refer to the Predefined Themes article for details on the themes that are supplied with DevExtreme.

initialized(callback)

Specifies a function to be executed after a theme is loaded.

Parameters:
callback:

Function

The function.

In some situations, UI components may apply their configuration or calculate their sizes before a theme is loaded. If you encounter issues with component appearance, use initialized(callback) to ensure that all styles are applied:

main.ts
  • import themes from 'devextreme/ui/themes';
  • // ...
  • themes.initialized(() => {
  • platformBrowserDynamic().bootstrapModule(AppModule)
  • .catch(err => console.error(err));
  • });

ready(callback)

Specifies a function to be executed each time a theme is switched.

Parameters:
callback:

Function

The function.

Refer to the current(themeName) description for a code example.