[[per-user-themes]]
= Per-user Themes

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From link:http://isis.markmail.org/thread/kb4442niwwbnghey[this thread] on the Apache Isis users mailing list:

* _Is it possible to have each of our resellers (using our Apache Isis application) use their own theme/branding with their own logo and colors?
Would this also be possible for the login page, possibly depending on the used host name?_


Yes, you can do this, by installing a custom implementation of the Wicket Bootstrap's `ActiveThemeProvider`:

[source,java]
.IActiveThemeProvider implementation
----
public class UserSettingsThemeProvider implements ActiveThemeProvider {
    ...
    @Override
    public ITheme getActiveTheme() {
        if(IsisContext.getSpecificationLoader().isInitialized()) {
            final String themeName = IsisContext.doInSession(new Callable<String>() {
                @Override
                public String call() throws Exception {
                    final UserSettingsService userSettingsService =
                        lookupService(UserSettingsService.class);
                    final UserSetting activeTheme = userSettingsService.find(
                            IsisContext.getAuthenticationSession().getUserName(),
                            ACTIVE_THEME);
                    return activeTheme != null ? activeTheme.valueAsString() : null;
                }
            });
            return themeFor(themeName);
        }
        return new SessionThemeProvider().getActiveTheme();
    }
    @Override
    public void setActiveTheme(final String themeName) {
        IsisContext.doInSession(new Runnable() {
            @Override
            public void run() {
                final String currentUsrName =
                    IsisContext.getAuthenticationSession().getUserName();
                final UserSettingsServiceRW userSettingsService =
                        lookupService(UserSettingsServiceRW.class);
                final UserSettingJdo activeTheme =
                        (UserSettingJdo) userSettingsService.find(
                                                currentUsrName, ACTIVE_THEME);
                if(activeTheme != null) {
                    activeTheme.updateAsString(themeName);
                } else {
                    userSettingsService.newString(
                        currentUsrName, ACTIVE_THEME, "Active Bootstrap theme for user", themeName);
                }
            }
        });
    }
    private ITheme themeFor(final String themeName) {
        final ThemeProvider themeProvider = settings.getThemeProvider();
        if(themeName != null) {
            for (final ITheme theme : themeProvider.available()) {
                if (themeName.equals(theme.name()))
                    return theme;
            }
        }
        return themeProvider.defaultTheme();
    }
    ...
}
----

and

[source,java]
.Using the ActiveThemeProvider
----
@Override
protected void init() {
    super.init();

    final IBootstrapSettings settings = Bootstrap.getSettings();
    settings.setThemeProvider(new BootswatchThemeProvider(BootswatchTheme.Flatly));

    settings.setActiveThemeProvider(new UserSettingsThemeProvider(settings));
}
----
