Package com.vaadin.base.devserver.hotswap.impl

Class StyleSheetHotswapper

java.lang.Object

com.vaadin.base.devserver.hotswap.impl.StyleSheetHotswapper

All Implemented Interfaces:

VaadinHotswapper

public class StyleSheetHotswapper
extends Object
implements VaadinHotswapper

Handles the automatic hotswapping of CSS resources and classes annotated with @StyleSheet, taking the appropriate actions to update stylesheets in the browser.

When a resource with .css extension is changed, this class determines if the related file exists in a known public folder (`META-INF/resource`, `resource`, `static`, `public`) in the output resources folder (e.g. `target/classes` for Maven) and triggers a resource update by the Vaadin Dev Server.

When a class with StyleSheet annotation is changed, this hotswapper:

• Adds new link tags when annotation is added
• Updates link tags when annotation value is changed
• Removes link tags when annotation is removed

For AppShellConfigurator classes, changes are applied globally to all UIs. For Component classes, changes are applied when the component is in use.

For internal use only. May be renamed or removed in a future release.

Since:

25.0

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	LOGGER

Constructor Summary

Constructors

Constructor	Description
StyleSheetHotswapper()

Method Summary

Modifier and Type	Method	Description
void	onClassesChange(HotswapClassEvent event)	Called by Vaadin hotswap entry point when one or more application classes have been updated.
void	onClassesChange(HotswapClassSessionEvent event)	Called by Vaadin hotswap entry point when one or more application classes have been updated.
void	onHotswapComplete(HotswapCompleteEvent event)	Called by Vaadin hotswap entry point after all hotswap related operations have been completed.
void	onInit(com.vaadin.flow.server.VaadinService vaadinService)	Called during the initialization of the Vaadin Hotswapper.
void	onResourcesChange(HotswapResourceEvent event)	Called by Vaadin hotswap entry point when one or more application resources have been updated.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.vaadin.base.devserver.hotswap.VaadinHotswapper

onClassLoadEvent, onClassLoadEvent

Field Details

LOGGER

public static final org.slf4j.Logger LOGGER

Constructor Details

StyleSheetHotswapper

public StyleSheetHotswapper()

Method Details

onInit

public void onInit(com.vaadin.flow.server.VaadinService vaadinService)

Description copied from interface: VaadinHotswapper

Called during the initialization of the Vaadin Hotswapper. This method provides an entry point for executing logic that needs to occur when the associated VaadinService is initialized and before any hotswap events are triggered.

Specified by:

onInit in interface VaadinHotswapper

Parameters:

vaadinService - the active VaadinService instance being initialized

onHotswapComplete

public void onHotswapComplete(HotswapCompleteEvent event)

Description copied from interface: VaadinHotswapper

Called by Vaadin hotswap entry point after all hotswap related operations have been completed.

Specified by:

onHotswapComplete in interface VaadinHotswapper

Parameters:

event - an event containing information about the hotswap operation.

onClassesChange

public void onClassesChange(HotswapClassEvent event)

Description copied from interface: VaadinHotswapper

Called by Vaadin hotswap entry point when one or more application classes have been updated.

This method is meant to perform application-wide updates. Operation targeting Vaadin session should be implemented in VaadinHotswapper.onClassesChange(HotswapClassSessionEvent) method.

Currently, the default implementation delegates to the deprecated VaadinHotswapper.onClassLoadEvent(VaadinService, Set, boolean) method for backward compatibility.

Specified by:

onClassesChange in interface VaadinHotswapper

Parameters:

event - the event instance carrying the information about the changed classes.

See Also:

• VaadinHotswapper.onClassesChange(HotswapClassSessionEvent)

onClassesChange

public void onClassesChange(HotswapClassSessionEvent event)

Description copied from interface: VaadinHotswapper

Called by Vaadin hotswap entry point when one or more application classes have been updated.

This method is meant to perform updates at VaadinSession level. Operation targeting the entire application should be implemented in VaadinHotswapper.onClassesChange(HotswapClassEvent) method.

Currently, the default implementation delegates to the deprecated VaadinHotswapper.onClassLoadEvent(VaadinSession, Set, boolean) method for backward compatibility.

Specified by:

onClassesChange in interface VaadinHotswapper

Parameters:

event - the event instance carrying the information about the changed classes.

See Also:

• VaadinHotswapper.onClassesChange(HotswapClassEvent)

onResourcesChange

public void onResourcesChange(HotswapResourceEvent event)

Description copied from interface: VaadinHotswapper

Called by Vaadin hotswap entry point when one or more application resources have been updated.

This method is meant to perform application-wide updates, involving all active UI instances.

Specified by:

onResourcesChange in interface VaadinHotswapper

Parameters:

event - the event instance carrying the information about the changed resources.