Merge pull request #75 from jmichaud/jmichaud/add_event_labels_to_export

Proposal to add the option to use event class names as transition labels in PlantUML export
KStateMachine · Dec 5, 2023 · 84446a6 · 84446a6
2 parents e5311b3 + bd423fe
commit 84446a6
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Showing 2 changed files with 10 additions and 7 deletions.
diff --git a/docs/index.md b/docs/index.md
@@ -873,7 +873,7 @@ to [PlantUML state diagram](https://plantuml.com/en/state-diagram).
 
 ```kotlin
 val machine = createStateMachine(scope) { /* ... */ }
-println(machine.exportToPlantUml())
+println(machine.exportToPlantUml(showEventLabels = false))
 ```
 
 Copy/paste resulting output to [Plant UML online editor](http://www.plantuml.com/plantuml/)

diff --git a/kstatemachine/src/commonMain/kotlin/ru/nsk/kstatemachine/visitors/ExportPlantUmlVisitor.kt b/kstatemachine/src/commonMain/kotlin/ru/nsk/kstatemachine/visitors/ExportPlantUmlVisitor.kt
@@ -9,7 +9,7 @@ import ru.nsk.kstatemachine.TransitionDirectionProducerPolicy.CollectTargetState
  *
  * Conditional transitions currently are not supported.
  */
-internal class ExportPlantUmlVisitor : CoVisitor {
+internal class ExportPlantUmlVisitor(val showEventLabels: Boolean = false) : CoVisitor {
     private val builder = StringBuilder()
     private var indent = 0
     private val crossLevelTransitions = mutableListOf<String>()
@@ -69,7 +69,8 @@ internal class ExportPlantUmlVisitor : CoVisitor {
             targetState.graphName()
         }
 
-        val transitionString = "$sourceState --> $graphName${label(transition.name)}"
+        val eventLabel = if(showEventLabels) transition.eventMatcher.eventClass.simpleName else null
+        val transitionString = "$sourceState --> $graphName${label(transition.name, eventLabel)}"
 
         if (transition.sourceState.isNeighbor(targetState))
             line(transitionString)
@@ -114,17 +115,19 @@ internal class ExportPlantUmlVisitor : CoVisitor {
             return if (this !is StateMachine) name else "${name}_StateMachine"
         }
 
-        fun label(name: String?) = if (name != null) " : $name" else ""
+        fun label(name: String?, eventName: String? = null) =
+            if (name == null && eventName == null) "" else
+                " :${name?.let { " $it" } ?: ""}${eventName?.let { " $it" } ?: ""}"
     }
 }
 
-suspend fun StateMachine.exportToPlantUml() = with(ExportPlantUmlVisitor()) {
+suspend fun StateMachine.exportToPlantUml(showEventLabels: Boolean = false) = with(ExportPlantUmlVisitor(showEventLabels)) {
     accept(this)
     export()
 }
 
-fun StateMachine.exportToPlantUmlBlocking() = coroutineAbstraction.runBlocking {
-    with(ExportPlantUmlVisitor()) {
+fun StateMachine.exportToPlantUmlBlocking(showEventLabels: Boolean = false) = coroutineAbstraction.runBlocking {
+    with(ExportPlantUmlVisitor(showEventLabels)) {
         accept(this)
         export()
     }