GH-989 - Allow registering skin parameters in generated PlantUML diagrams.

Author: Alexander-Miller

spring-modulith-docs/src/main/java/org/springframework/modulith/docs/Documenter.java

@@ -35,6 +35,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import com.structurizr.export.plantuml.AbstractPlantUMLExporter;
 import org.springframework.lang.Nullable;
 import org.springframework.modulith.core.ApplicationModule;
 import org.springframework.modulith.core.ApplicationModuleDependency;
@@ -565,6 +566,7 @@ private String render(ComponentView view, DiagramOptions options) {
 			case C4:
 
 				var c4PlantUmlExporter = new C4PlantUMLExporter();
+				addSkinParamsFromOptions(c4PlantUmlExporter, options);
 				var diagram = c4PlantUmlExporter.export(view);
 
 				return diagram.getDefinition();
@@ -573,12 +575,19 @@ private String render(ComponentView view, DiagramOptions options) {
 			default:
 
 				var plantUmlExporter = new CustomizedPlantUmlExporter();
+				addSkinParamsFromOptions(plantUmlExporter, options);
 				plantUmlExporter.addSkinParam("componentStyle", "uml1");
 
 				return plantUmlExporter.export(view).getDefinition();
 		}
 	}
 
+	private void addSkinParamsFromOptions(AbstractPlantUMLExporter exporter, DiagramOptions options) {
+		for (var skinParamEntry : options.skinParams.entrySet()) {
+			exporter.addSkinParam(skinParamEntry.getKey(), skinParamEntry.getValue());
+		}
+	}
+
 	private String createPlantUml(DiagramOptions options) {
 
 		ComponentView componentView = createComponentView(options);
@@ -692,6 +701,7 @@ public static class DiagramOptions {
 		private final Function<ApplicationModule, String> defaultDisplayName;
 		private final DiagramStyle style;
 		private final ElementsWithoutRelationships elementsWithoutRelationships;
+		private final Map<String, String> skinParams;
 
 		/**
 		 * @param dependencyTypes must not be {@literal null}.
@@ -704,13 +714,15 @@ public static class DiagramOptions {
 		 * @param defaultDisplayName must not be {@literal null}.
 		 * @param style must not be {@literal null}.
 		 * @param elementsWithoutRelationships must not be {@literal null}.
+		 * @param skinParams must not be {@literal null}.
 		 */
 		DiagramOptions(Set<DependencyType> dependencyTypes, DependencyDepth dependencyDepth,
 				Predicate<ApplicationModule> exclusions, Predicate<Component> componentFilter,
 				Predicate<ApplicationModule> targetOnly, @Nullable String targetFileName,
 				Function<ApplicationModule, Optional<String>> colorSelector,
 				Function<ApplicationModule, String> defaultDisplayName, DiagramStyle style,
-				ElementsWithoutRelationships elementsWithoutRelationships) {
+				ElementsWithoutRelationships elementsWithoutRelationships,
+				Map<String, String> skinParams) {
 
 			Assert.notNull(dependencyTypes, "Dependency types must not be null!");
 			Assert.notNull(dependencyDepth, "Dependency depth must not be null!");
@@ -721,6 +733,7 @@ public static class DiagramOptions {
 			Assert.notNull(defaultDisplayName, "Default display name must not be null!");
 			Assert.notNull(style, "DiagramStyle must not be null!");
 			Assert.notNull(elementsWithoutRelationships, "ElementsWithoutRelationships must not be null!");
+			Assert.notNull(skinParams, "SkinParams must not be null!");
 
 			this.dependencyTypes = dependencyTypes;
 			this.dependencyDepth = dependencyDepth;
@@ -732,30 +745,31 @@ public static class DiagramOptions {
 			this.defaultDisplayName = defaultDisplayName;
 			this.style = style;
 			this.elementsWithoutRelationships = elementsWithoutRelationships;
+			this.skinParams = skinParams;
 		}
 
 		/**
 		 * The {@link DependencyDepth} to define which other modules to be included in the diagram to be created.
 		 */
 		public DiagramOptions withDependencyDepth(DependencyDepth dependencyDepth) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
 		 * A {@link Predicate} to define the which modules to exclude from the diagram to be created.
 		 */
 		public DiagramOptions withExclusions(Predicate<ApplicationModule> exclusions) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
 		 * A {@link Predicate} to define which Structurizr {@link Component}s to be included in the diagram to be created.
 		 */
 		public DiagramOptions withComponentFilter(Predicate<Component> componentFilter) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
@@ -765,7 +779,7 @@ public DiagramOptions withComponentFilter(Predicate<Component> componentFilter)
 		 */
 		public DiagramOptions withTargetOnly(Predicate<ApplicationModule> targetOnly) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
@@ -777,15 +791,15 @@ public DiagramOptions withTargetFileName(String targetFileName) {
 			Assert.isTrue(targetFileName.contains("%s"), () -> INVALID_FILE_NAME_PATTERN.formatted(targetFileName));
 
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
 		 * A callback to return a hex-encoded color per {@link ApplicationModule}.
 		 */
 		public DiagramOptions withColorSelector(Function<ApplicationModule, Optional<String>> colorSelector) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
@@ -794,15 +808,15 @@ public DiagramOptions withColorSelector(Function<ApplicationModule, Optional<Str
 		 */
 		public DiagramOptions withDefaultDisplayName(Function<ApplicationModule, String> defaultDisplayName) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
 		 * Which style to render the diagram in. Defaults to {@link DiagramStyle#UML}.
 		 */
 		public DiagramOptions withStyle(DiagramStyle style) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
@@ -815,7 +829,18 @@ public DiagramOptions withStyle(DiagramStyle style) {
 		 */
 		public DiagramOptions withElementsWithoutRelationships(ElementsWithoutRelationships elementsWithoutRelationships) {
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
-					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
+		}
+
+		/**
+		 * Configuration setting to add arbitrary skin parameters to the created diagrams.
+		 *
+		 * Applies to both the UML and C4 {@link DiagramStyle styles}.
+		 */
+		public DiagramOptions withSkinParam(String name, String value) {
+			skinParams.put(name, value);
+			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
+					targetFileName, colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		/**
@@ -828,7 +853,7 @@ public DiagramOptions withElementsWithoutRelationships(ElementsWithoutRelationsh
 		public static DiagramOptions defaults() {
 			return new DiagramOptions(ALL_TYPES, DependencyDepth.IMMEDIATE, it -> false, it -> true, it -> false, null,
 					__ -> Optional.empty(), it -> it.getDisplayName(), DiagramStyle.C4,
-					ElementsWithoutRelationships.HIDDEN);
+					ElementsWithoutRelationships.HIDDEN, new LinkedHashMap<>());
 		}
 
 		/**
@@ -845,7 +870,7 @@ public DiagramOptions withDependencyTypes(DependencyType... types) {
 
 			return new DiagramOptions(dependencyTypes, dependencyDepth, exclusions, componentFilter, targetOnly,
 					targetFileName,
-					colorSelector, defaultDisplayName, style, elementsWithoutRelationships);
+					colorSelector, defaultDisplayName, style, elementsWithoutRelationships, skinParams);
 		}
 
 		private Optional<String> getTargetFileName() {