com.vaadin.flow.server

Annotation Type PWA

@Retention(value=RUNTIME)
 @Target(value=TYPE)
public @interface PWA

Defines application PWA properties. Annotation activates automatic PWA injecting.

Only one annotation for application is supported. Annotation must be placed to master layout. Application annotated the annotation will add following capabilities to Flow application:

• handle manifest.webmanifest
• handle sw.js (service worker), which will enable simple offline fallback and file caching
• handle default (static) offline html page
• handle different versions (sizes) of the given logo
• inject needed tags to the app's page header

Any of the handled resources can be explicitly overridden with static file in public resources. For example, if manifest.webmanifest is available in webapp root folder it will be served instead of generated manifest.webmanifest. Same applies for service worker and generated icons. NOTE: PWA Install Prompt feature will be removed in future versions since this feature was only supported by Chromium-based browsers, in favour of a more uniform implementation and experience for all browsers.

Since:

1.2

See Also:

https://developer.mozilla.org/en-US/Apps/Progressive

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String	name Name of the application.
String	shortName Short name for the application.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	backgroundColor Background color of the application.
String	description Description of the application.
String	display Defines the developers’ preferred display mode for the website.
boolean	enableInstallPrompt If enabled, server will inject default pwa -install prompt html and js in bootstrap page.
String	iconPath Path to the application icon file.
String	manifestPath Path to the manifest file.
String	offlinePath Path to the static offline html file.
String[]	offlineResources Offline resources to be cached using the service worker.
String	startPath (Root relative) start url, used in web-manifest, property start_url
String	themeColor Theme color of the application.

Element Detail

name

public abstract String name

Name of the application.

Returns:

name of the application

shortName

public abstract String shortName

Short name for the application. Maximum of 12 characters.

Returns:

short name for the application

offlinePath

public abstract String offlinePath

Path to the static offline html file. Defaults to (relative) offline.html with default configuration that is webapp/offline.html If offline file is not found, falls back to default offline page.

Returns:

path to the static offline html file

Default:

"offline.html"

manifestPath

public abstract String manifestPath

Path to the manifest file. Defaults to (relative) manifest.webmanifest with default configuration that is webapp/manifest.webmanifest

Returns:

path to the manifest file

Default:

"manifest.webmanifest"

iconPath

public abstract String iconPath

Path to the application icon file.

Defaults to (relative) icons/icon.png with default configuration that is webapp/manifest.webmanifest

If the specified icon file is not found, the default one will be used. The file is also used to create different sizes of icon.

Returns:

path to the application icon file

Default:

"icons/icon.png"

startPath

public abstract String startPath

(Root relative) start url, used in web-manifest, property start_url

Used in manifest as start_url of application. Must be relative to root context. ie. If install address of application would be https://foo.bar.org/sub/ and wanted start url would be https://foo.bar.org/sub/pwa-start then value of startPath would be "pwa-start" (without leading "/").

Defaults to root of application.

Returns:

application start url

Default:

""

description

public abstract String description

Description of the application.

Returns:

description of the application

Default:

""

themeColor

public abstract String themeColor

Theme color of the application. The theme color sets the color of the application's tool bar and application's color in the task switcher.

Returns:

theme color of the application

Default:

"#ffffff"

backgroundColor

public abstract String backgroundColor

Background color of the application. The background color property is used on the splash screen when the application is first launched.

Returns:

Background color of the application

Default:

"#f2f2f2"

display

public abstract String display

Defines the developers’ preferred display mode for the website. Possible values: fullscreen, standalone, minimal-ui, browser

Returns:

display mode of application

Default:

"standalone"

offlineResources

public abstract String[] offlineResources

Offline resources to be cached using the service worker.

Returns:

offline resources to be cached

Default:

{}

enableInstallPrompt

public abstract boolean enableInstallPrompt

If enabled, server will inject default pwa -install prompt html and js in bootstrap page.

Will capture beforeinstallprompt -event and show install prompt as required from Chrome 68 upwards.

Returns:

are pwa -install prompt resources injected.

Default:

true