Grid Helper Dense Mode does not work with productive build

Describe the bug

The dense mode does not work in production mode. Maybe the styles are not bundled when the production bundle is created?

Expected behavior

No response

Minimal reproducible example

No response

Add-on Version

2.0.0

Vaadin Version

25

Additional information

No response

@timomeinen

Hi @timomeinen !
Dense mode seems to be working on our demo application that is actually deployed in production mode.
Can you try creating a new small sample application, integrate the add-on, copy the demos and then run it in production mode? .. if it works, compare it to your application to spot significant differences, if it doesn't attach the sample project here so we can take a look.
Thanks!

Showcase dense mode in production mode not working

@mlopezFC

Hi @mlopezFC,

please find a small example of the problem here: https://github.com/timomeinen/grid-helpers-issue-171

I have just added a checkbox of the DENSE mode to the start.vaadin.com demo application.

I remember I had a similar issue with a different plugin and solved it by manually referencing the JS via Annotation to force it being packed into the prod.bundle. Here also the vaadin:build-frontend does not pickup the dependency and says, no bundle is needed:

[INFO] --- vaadin:25.0.7:build-frontend (default-cli) @ app ---
[INFO] Reflections took 725 ms to scan 118 urls, producing 5125 keys and 20651 values
[INFO] Scanning classes to find frontend configurations and dependencies...
[INFO] Visited 1255 classes. Took 1006 ms.
[INFO] Checking if a production mode bundle build is needed
[INFO] A production mode bundle build is not needed

A production mode bundle build is not needed

The problem is that GridHelper is not recognized as Vaadin Component by the vaadin-maven-plugin and thus it does not recognize the @CssImport(value = "./fcGridHelper/vaadin-menu-bar.css", themeFor = "vaadin-menu-bar"). The result is that the CSS is missing in the bundle:

❯ grep "fcGridHelper/vaadin-menu-bar.css" target/classes/META-INF/VAADIN/config/stats.json

In contrast the dev mode bundle has the required file:

❯ grep "fcGridHelper/vaadin-menu-bar.css" target/dev-bundle/config/stats.json

  "Frontend/generated/jar-resources/fcGridHelper/vaadin-menu-bar.css",
  "fcGridHelper/vaadin-menu-bar.css": "6d32eb58d19bd3dc5a606b217e67b7b358cca3d4eb55ed06b38c57e48fdeb9be",

I tried to use com.vaadin.flow.component.dependency.Uses to give Vaadin a hint to include Grid-Helpers StyleSheets and JavaScript dependencies, but as GridHelper is not a com.vaadin.flow.component.Component it does not work:

@Uses(GridHelper.class) // Compile error as GridHelper is not instanceof Component

Instead, when we force bundling by disabling the byte-code scanner with <optimizeBundle>false</optimizeBundle>, it works:

<plugin>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-maven-plugin</artifactId>
    <version>${vaadin.version}</version>
    <configuration>
        <optimizeBundle>false</optimizeBundle>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>build-frontend</goal>
            </goals>
        </execution>
    </executions>
</plugin>

This will add the files to the prod bundle:

❯ grep "fcGridHelper/vaadin-menu-bar.css" target/classes/META-INF/VAADIN/config/stats.json
  "Frontend/generated/jar-resources/fcGridHelper/vaadin-menu-bar.css",
  "fcGridHelper/vaadin-menu-bar.css": "6d32eb58d19bd3dc5a606b217e67b7b358cca3d4eb55ed06b38c57e48fdeb9be",

But this is not ideal as the prod bundle will now be unneccassary big.

Note: adding the CSS import to my own view, works as well of course:

@CssImport(value = GridHelper.GRID_STYLES, themeFor = "vaadin-grid")

Hello. Did you add com.flowingcode to whitelisted-packages?

https://github.com/FlowingCode/GridHelpers?tab=readme-ov-file#special-configuration-when-using-spring

@javier-godoy

Hi @javier-godoy,

whitelisted-packages is deprecated but adding com.flowingcode is added to either whitelisted-packages or vaadin.allowed-packages:

vaadin.whitelisted-packages=com.vaadin,org.vaadin,com.flowingcode,com.example.app
vaadin.allowed-packages=com.vaadin,org.vaadin,com.flowingcode,com.example.app

No change. the fcGridHelper resources are not added to the bundle:

❯ grep "fcGridHelper/" target/classes/META-INF/VAADIN/config/stats.json

I'll take a look.

The vaadin-maven-plugin production bundle scanner is reachability-based: it seeds from known entry points and follows bytecode references to discover @CssImport / @JsModule dependencies.

When a view calls a GridHelper method, javac emits an instruction naming GridHelper as the owner class. The FrontendClassVisitor adds it to the reachability set, then the scanner visits GridHelper, and its @CssImport annotations are picked up. This is why our demo application works correctly in production (the demo for the dense theme feature is compiled with other demos that cause GridHelper to be reachable).

In your sample project, only the DENSE_THEME constant is used. Javac inlines the constant and emits no field-access instruction at all
(it's the same as if you had written grid.addThemeName("fcGh-dense")). Therefore GridHelper never appears in any executable instruction, the scanner never reaches it, and its annotations are not processed.

fix: register VaadinServiceInitListener to bundle grid styles

fix: ensure dense theme CSS is included in production bundle

The fix from commit 9ade7ea works, but I've created an alternative approach in #175 that I think is cleaner.

Instead of the VaadinServiceInitListener anchor class, it adds setDenseTheme(Grid, boolean) and isDenseTheme(Grid) methods. This solves the production bundle problem the same way (a method call creates a bytecode reference to GridHelper, so the scanner finds its @CssImport annotations), but it's also more consistent with the rest of the GridHelper API where every feature follows the GridHelper.setSomething(grid, value) / GridHelper.isSomething(grid) pattern — the dense theme was the only one that required direct theme name manipulation.

@timomeinen

Thanks @timomeinen for this alternative. It's really interesting, we will discuss about it next week and we will keep you posted.

Is it possible to release a patch version of the existing solution (GridHelperServiceInitListener) as we depend on this feature and I would like to get rid of my local hack?

fix: ensure dense theme CSS is included in production bundle

@timomeinen

@timomeinen I'll revert #173 and release it with your changes, since it's a more clear approach.

fix: ensure dense theme CSS is included in production bundle

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Grid Helper Dense Mode does not work with productive build #171

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Grid Helper Dense Mode does not work with productive build #171

Description

Describe the bug

Expected behavior

Minimal reproducible example

Add-on Version

Vaadin Version

Additional information

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mlopezFC commented on Mar 19, 2026

timomeinen commented on Mar 19, 2026

timomeinen commented on Mar 23, 2026

timomeinen commented on Mar 23, 2026

javier-godoy commented on Mar 24, 2026

timomeinen commented on Mar 24, 2026

javier-godoy commented on Mar 24, 2026

javier-godoy commented on Mar 26, 2026

timomeinen commented on Mar 27, 2026

paodb commented on Mar 27, 2026

timomeinen commented on Apr 8, 2026

javier-godoy commented on Apr 8, 2026

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