fix(#5251): expose the colors configured in the settings directly rather then calling a method which is not allowed from Thymeleaf 3.1.4

spring-boot-admin-samples/spring-boot-admin-sample-reactive/src/main/resources/application-themed.yml

@@ -0,0 +1,17 @@
+spring:
+  boot:
+    admin:
+      ui:
+        theme:
+          color: "#4A1420"
+          palette:
+            50: "#F8EBE4"
+            100: "#F2D7CC"
+            200: "#E5AC9C"
+            300: "#D87B6C"
+            400: "#CB463B"
+            500: "#9F2A2A"
+            600: "#83232A"
+            700: "#661B26"
+            800: "#4A1420"
+            900: "#2E0C16"

spring-boot-admin-server-ui/src/main/frontend/public/variables.css

@@ -1,17 +1,17 @@
 :root {
-  --main-50: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade50())})]*/ #e8fbef;
-  --main-100: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade100())})]*/ #d0f7df;
-  --main-200: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade200())})]*/ #a1efbd;
-  --main-300: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade300())})]*/ #71e69c;
-  --main-400: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade400())})]*/ #41de7b;
-  --main-500: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade500())})]*/ #22c55e;
-  --main-600: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade600())})]*/ #1a9547;
-  --main-700: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade700())})]*/ #116530;
-  --main-800: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade800())})]*/ #09351a;
-  --main-900: /*[(${@cssColorUtils.hexToRgb(uiSettings.theme.palette.getShade900())})]*/ #010603;
+  --main-50: /*[(${palette.rgbColor50})]*/ #e8fbef;
+  --main-100: /*[(${palette.rgbColor100})]*/ #d0f7df;
+  --main-200: /*[(${palette.rgbColor200})]*/ #a1efbd;
+  --main-300: /*[(${palette.rgbColor300})]*/ #71e69c;
+  --main-400: /*[(${palette.rgbColor400})]*/ #41de7b;
+  --main-500: /*[(${palette.rgbColor500})]*/ #22c55e;
+  --main-600: /*[(${palette.rgbColor600})]*/ #1a9547;
+  --main-700: /*[(${palette.rgbColor700})]*/ #116530;
+  --main-800: /*[(${palette.rgbColor800})]*/ #09351a;
+  --main-900: /*[(${palette.rgbColor900})]*/ #010603;
 
-  --bg-color-start: /*[(${uiSettings.theme.palette.getShade300()})]*/ #71e69c;
-  --bg-color-stop: /*[(${uiSettings.theme.palette.getShade700()})]*/ #09351a;
+  --bg-color-start: /*[(${uiSettings.theme.palette.shade300})]*/ #71e69c;
+  --bg-color-stop: /*[(${uiSettings.theme.palette.shade700})]*/ #09351a;
 }
 
 .bg-color-start {

spring-boot-admin-server-ui/src/main/java/de/codecentric/boot/admin/server/ui/config/AdminServerUiAutoConfiguration.java

@@ -90,11 +90,6 @@ public AdminServerUiAutoConfiguration(AdminServerUiProperties adminUi, AdminServ
 		this.applicationContext = applicationContext;
 	}
 
-	@Bean
-	public CssColorUtils cssColorUtils() {
-		return new CssColorUtils();
-	}
-
 	@Bean
 	@ConditionalOnMissingBean
 	public UiController homeUiController(UiExtensions uiExtensions) throws IOException {

spring-boot-admin-server-ui/src/main/java/de/codecentric/boot/admin/server/ui/config/CssColorUtils.java

@@ -18,11 +18,14 @@
 
 import java.util.regex.Pattern;
 
-public class CssColorUtils {
+public final class CssColorUtils {
+
+	private CssColorUtils() {
+	}
 
 	private static final Pattern HEX_RGB_PATTERN = Pattern.compile("^#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$");
 
-	public String hexToRgb(String color) {
+	public static String hexToRgb(String color) {
 		if (!HEX_RGB_PATTERN.matcher(color).matches()) {
 			throw new IllegalArgumentException(String.format("Invalid hex rgb format %s", color));
 		}

spring-boot-admin-server-ui/src/main/java/de/codecentric/boot/admin/server/ui/config/ServerRuntimeHints.java

@@ -124,8 +124,6 @@ private static void registerReflectionHints(org.springframework.aot.hint.Runtime
 					MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS)
 			.registerType(AdminServerUiProperties.PollTimer.class, MemberCategory.INVOKE_PUBLIC_METHODS,
 					MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS)
-			.registerType(CssColorUtils.class, MemberCategory.INVOKE_PUBLIC_METHODS,
-					MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS)
 			.registerType(InstanceDeregisteredEvent.class, MemberCategory.INVOKE_PUBLIC_METHODS,
 					MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS)
 			.registerType(InstanceEndpointsDetectedEvent.class, MemberCategory.INVOKE_PUBLIC_METHODS,

spring-boot-admin-server-ui/src/main/java/de/codecentric/boot/admin/server/ui/web/UiController.java

@@ -19,6 +19,7 @@
 import java.security.Principal;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
@@ -31,8 +32,10 @@
 import org.springframework.web.util.UriComponents;
 import org.springframework.web.util.UriComponentsBuilder;
 
+import de.codecentric.boot.admin.server.ui.config.AdminServerUiProperties.Palette;
 import de.codecentric.boot.admin.server.ui.config.AdminServerUiProperties.PollTimer;
 import de.codecentric.boot.admin.server.ui.config.AdminServerUiProperties.UiTheme;
+import de.codecentric.boot.admin.server.ui.config.CssColorUtils;
 import de.codecentric.boot.admin.server.ui.extensions.UiExtension;
 import de.codecentric.boot.admin.server.ui.extensions.UiExtensions;
 import de.codecentric.boot.admin.server.web.AdminController;
@@ -97,6 +100,15 @@ public Map<String, Object> getUser(@Nullable Principal principal) {
 		return emptyMap();
 	}
 
+	@ModelAttribute(value = "palette", binding = false)
+	public Map<String, String> getPalette() {
+		return Map.ofEntries(hexToRgbColor(50, Palette::getShade50), hexToRgbColor(100, Palette::getShade100),
+				hexToRgbColor(200, Palette::getShade200), hexToRgbColor(300, Palette::getShade300),
+				hexToRgbColor(400, Palette::getShade400), hexToRgbColor(500, Palette::getShade500),
+				hexToRgbColor(600, Palette::getShade600), hexToRgbColor(700, Palette::getShade700),
+				hexToRgbColor(800, Palette::getShade800), hexToRgbColor(900, Palette::getShade900));
+	}
+
 	@GetMapping(path = "/", produces = MediaType.TEXT_HTML_VALUE)
 	@RegisterReflectionForBinding(String.class)
 	public String index() {
@@ -113,6 +125,11 @@ public String variablesCss() {
 		return "variables.css";
 	}
 
+	private Map.Entry<String, String> hexToRgbColor(int grade, Function<Palette, String> hexColorGetter) {
+		return Map.entry(("rgbColor" + grade).intern(),
+				CssColorUtils.hexToRgb(hexColorGetter.apply(uiSettings.getTheme().getPalette())));
+	}
+
 	@GetMapping(path = "/login", produces = MediaType.TEXT_HTML_VALUE)
 	public String login() {
 		return "login";

spring-boot-admin-server-ui/src/test/java/de/codecentric/boot/admin/server/ui/AbstractAdminUiApplicationTest.java

@@ -150,6 +150,31 @@ public void should_return_defaults_for_pollTimers() {
 		//@formatter:on
 	}
 
+	@Test
+	public void should_render_palette_colors_in_variables_css() {
+		//@formatter:off
+		this.webClient.get()
+					.uri("/variables.css")
+					.accept(MediaType.parseMediaType("text/css"), MediaType.ALL)
+					.exchange()
+					.expectStatus().isOk()
+					.expectHeader().contentTypeCompatibleWith(MediaType.parseMediaType("text/css"))
+					.expectBody(String.class)
+					.value((body) -> assertThat(body).contains("--main-50: rgb(238, 252, 250)"))
+					.value((body) -> assertThat(body).contains("--main-100: rgb(217, 247, 244)"))
+					.value((body) -> assertThat(body).contains("--main-200: rgb(183, 240, 234)"))
+					.value((body) -> assertThat(body).contains("--main-300: rgb(145, 232, 224)"))
+					.value((body) -> assertThat(body).contains("--main-400: rgb(107, 224, 213)"))
+					.value((body) -> assertThat(body).contains("--main-500: rgb(71, 217, 203)"))
+					.value((body) -> assertThat(body).contains("--main-600: rgb(39, 190, 175)"))
+					.value((body) -> assertThat(body).contains("--main-700: rgb(30, 144, 132)"))
+					.value((body) -> assertThat(body).contains("--main-800: rgb(20, 97, 90)"))
+					.value((body) -> assertThat(body).contains("--main-900: rgb(10, 47, 43)"))
+					.value((body) -> assertThat(body).contains("--bg-color-start: #91E8E0"))
+					.value((body) -> assertThat(body).contains("--bg-color-stop: #1E9084"));
+		//@formatter:on
+	}
+
 	protected WebTestClient createWebClient(int port) {
 		return WebTestClient.bindToServer().baseUrl("http://localhost:" + port).build();
 	}

spring-boot-admin-server-ui/src/test/java/de/codecentric/boot/admin/server/ui/config/CssColorUtilsTest.java

@@ -23,17 +23,13 @@ class CssColorUtilsTest implements WithAssertions {
 
 	@Test
 	void hexToRgb() {
-		CssColorUtils cssColorUtils = new CssColorUtils();
-
-		assertThat(cssColorUtils.hexToRgb(new AdminServerUiProperties.Palette().getShade50()))
+		assertThat(CssColorUtils.hexToRgb(new AdminServerUiProperties.Palette().getShade50()))
 			.isEqualTo("rgb(238, 252, 250)");
 	}
 
 	@Test
 	void hexToRgb_throws_exception_on_invalid_format() {
-		CssColorUtils cssColorUtils = new CssColorUtils();
-
-		assertThatThrownBy(() -> cssColorUtils.hexToRgb("EEFCFA")).isInstanceOf(IllegalArgumentException.class);
+		assertThatThrownBy(() -> CssColorUtils.hexToRgb("EEFCFA")).isInstanceOf(IllegalArgumentException.class);
 	}
 
 }

spring-boot-admin-server-ui/src/test/java/de/codecentric/boot/admin/server/ui/web/UiControllerTest.java

@@ -17,16 +17,20 @@
 package de.codecentric.boot.admin.server.ui.web;
 
 import java.util.List;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 
+import de.codecentric.boot.admin.server.ui.config.AdminServerUiProperties;
+import de.codecentric.boot.admin.server.ui.config.CssColorUtils;
 import de.codecentric.boot.admin.server.ui.extensions.UiExtensions;
 import de.codecentric.boot.admin.server.web.servlet.AdminControllerHandlerMapping;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.model;
@@ -98,8 +102,43 @@ void should_validate_external_views(String label, String url, boolean hasChildre
 		}
 	}
 
+	@Test
+	void should_populate_palette_with_matching_rgb_colors_for_all_grades() {
+		AdminServerUiProperties.Palette palette = new AdminServerUiProperties.Palette();
+		palette.set50("#010203");
+		palette.set100("#111213");
+		palette.set200("#212223");
+		palette.set300("#313233");
+		palette.set400("#414243");
+		palette.set500("#515253");
+		palette.set600("#616263");
+		palette.set700("#717273");
+		palette.set800("#818283");
+		palette.set900("#919293");
+
+		AdminServerUiProperties.UiTheme theme = new AdminServerUiProperties.UiTheme();
+		theme.setPalette(palette);
+
+		UiController.Settings settings = UiController.Settings.builder().theme(theme).build();
+		UiController controller = new UiController("", UiExtensions.EMPTY, settings);
+
+		Map<String, String> actualPalette = controller.getPalette();
+
+		assertThat(actualPalette)
+			.containsExactlyInAnyOrderEntriesOf(Map.of("rgbColor50", CssColorUtils.hexToRgb(palette.getShade50()),
+					"rgbColor100", CssColorUtils.hexToRgb(palette.getShade100()), "rgbColor200",
+					CssColorUtils.hexToRgb(palette.getShade200()), "rgbColor300",
+					CssColorUtils.hexToRgb(palette.getShade300()), "rgbColor400",
+					CssColorUtils.hexToRgb(palette.getShade400()), "rgbColor500",
+					CssColorUtils.hexToRgb(palette.getShade500()), "rgbColor600",
+					CssColorUtils.hexToRgb(palette.getShade600()), "rgbColor700",
+					CssColorUtils.hexToRgb(palette.getShade700()), "rgbColor800",
+					CssColorUtils.hexToRgb(palette.getShade800()), "rgbColor900",
+					CssColorUtils.hexToRgb(palette.getShade900())));
+	}
+
 	private MockMvc setupController(String publicUrl, List<UiController.ExternalView> externalViews) {
-		var uiControllerSettings = UiController.Settings.builder();
+		var uiControllerSettings = UiController.Settings.builder().theme(new AdminServerUiProperties.UiTheme());
 		if (!isEmpty(externalViews)) {
 			uiControllerSettings.externalViews(externalViews);
 		}