com.vaadin.annotations.StyleSheet Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.annotations;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import com.vaadin.server.ClientConnector;
/**
* If this annotation is present on a {@link ClientConnector} class, the
* framework ensures the referenced style sheets are loaded before the init
* method for the corresponding client-side connector is invoked.
*
* Absolute URLs including protocol and host are used as is on the client-side.
* Relative URLs are mapped to APP/PUBLISHED/[url] which are by default served
* from the classpath relative to the class where the annotation is defined.
*
* The file is only loaded if it has not already been loaded, determined as
* follows:
*
* - For absolute URLs, the URL is considered loaded if the same URL has
* previously been loaded using {@code StyleSheet} or if a
* {@code } tag using the same URL was present in the DOM
* when the Vaadin client-side was initialized.
*
- For relative URLs, the URL is considered loaded if another file with the
* same name has already been loaded using {@code StyleSheet}, even if that file
* was loaded from a different folder.
*
*
* Special Vaadin urls are also supported. The most useful is vaadin:// which
* maps to the location of the automatically published VAADIN folder located on
* your classpath in your resources. Using the VAADIN folder and vaadin:// you
* can publish stylesheets which use images or other files with relative paths.
* Another example is the theme:// url which maps to the location of your
* current theme.
*
* Example:
* @StyleSheet({"https://host.com/file1.css", "file2.css"}) on the
* class com.example.MyConnector would load the file https://host.com/file1.css
* as is and file2.css from /com/example/file2.css on the server's classpath
* using the ClassLoader that was used to load com.example.MyConnector.
*
* For adding multiple style sheets for a single component, you can use this
* annotation multiple times.
*
* @author Vaadin Ltd
* @since 7.0.0
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Repeatable(InternalContainerAnnotationForSS.class)
public @interface StyleSheet {
/**
* Style sheets to load before initializing the client-side connector.
*
* @return an array of style sheet urls
*/
public String[] value();
}