Package com.vaadin.flow.server.frontend

Class CssBundler

java.lang.Object

com.vaadin.flow.server.frontend.CssBundler

public class CssBundler
extends Object

Utility methods to handle application theme CSS content.

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

Constructor Summary

Constructors

Constructor	Description
CssBundler()

Method Summary

Modifier and Type	Method	Description
static String	inlineImportsForPublicResources(File baseFolder, File cssFile, String contextPath)	Inlines imports for CSS files located under public static resources (e.g.
static String	inlineImportsForThemes(File themeFolder, File cssFile, tools.jackson.databind.JsonNode themeJson)	Recurse over CSS import and inlines all ot them into a single CSS block in themes folder under src/main/frontend/themes/<theme-name>.

Methods inherited from class java.lang.Object

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

Constructor Details

CssBundler

public CssBundler()

Method Details

inlineImportsForThemes

public static String inlineImportsForThemes(File themeFolder,
 File cssFile,
 tools.jackson.databind.JsonNode themeJson)
                                     throws IOException

Recurse over CSS import and inlines all ot them into a single CSS block in themes folder under src/main/frontend/themes/<theme-name>.

Unresolvable imports are put on the top of the resulting code, because @import statements must come before any other CSS instruction, otherwise the import is ignored by the browser.

Along with import resolution and code inline, URLs (url('image.png') referencing theme resources or assets are rewritten to be correctly served by Vaadin at runtime.

Parameters:

themeFolder - location of theme folder on the filesystem.

cssFile - the CSS file to process.

themeJson - the theme configuration, usually stored in theme.json file.

Returns:

the processed stylesheet content, with inlined imports and rewritten URLs.

Throws:

IOException - if filesystem resources can not be read.

inlineImportsForPublicResources

public static String inlineImportsForPublicResources(File baseFolder,
 File cssFile,
 String contextPath)
                                              throws IOException

Inlines imports for CSS files located under public static resources (e.g. META-INF/resources).

Parameters:

baseFolder - base folder the imports and url() references are relative to

cssFile - the CSS file to process

contextPath - that url() are rewritten to and rebased onto

Returns:

the processed stylesheet content with inlined imports only

Throws:

IOException - if filesystem resources cannot be read