support default initial state

squirrel-foundation/src/main/java/org/squirrelframework/foundation/fsm/StateMachineBuilder.java

@@ -205,6 +205,11 @@ MutableState<T, S, E, C> defineTimedState(S stateId, long initialDelay,
      * @param terminateEvent
      */
     void defineTerminateEvent(E terminateEvent);
+
+    /**
+     * Define default initial state for state machine started
+     */
+    void defineDefaultInitialState(S stateId);
 
     /**
      * Define on entry actions for state
@@ -222,22 +227,22 @@ MutableState<T, S, E, C> defineTimedState(S stateId, long initialDelay,
 
     /**
      * Create a new state machine instance
-     * @param initialStateId initial state id
+     * @param initialStateId initial state id, null means using the default
      * @return new state machine instance
      */
     T newStateMachine(S initialStateId);
 
     /**
      * Create new state machine instance according to state machine definition 
-     * @param initialStateId the id of state machine initial state
+     * @param initialStateId the id of state machine initial state, null means using the default
      * @param extraParams other parameters for instantiate state machine
      * @return new state machine
      */
     T newStateMachine(S initialStateId, Object... extraParams);
 
     /**
      * Create new state machine instance according to state machine definition
-     * @param initialStateId the id of state machine initial state
+     * @param initialStateId the id of state machine initial state, null means using the default
      * @param configuration configuration for state machine
      * @param extraParams other parameters for instantiate state machine
      * @return new state machine

squirrel-foundation/src/main/java/org/squirrelframework/foundation/fsm/impl/StateMachineBuilderImpl.java

@@ -62,6 +62,8 @@ public class StateMachineBuilderImpl<T extends StateMachine<T, S, E, C>, S, E, C
     private final MvelScriptManager scriptManager;
 
     private E startEvent, finishEvent, terminateEvent;
+
+    private S defaultInitStateId;
 
     private final ExecutionContext executionContext;
 
@@ -701,6 +703,7 @@ public T newStateMachine(S initialStateId, Object... extraParams) {
     @Override
     public T newStateMachine(S initialStateId, StateMachineConfiguration configuration, Object... extraParams) {
         if(!prepared) prepare();
+        if (initialStateId == null) initialStateId = defaultInitStateId;
         if(!isValidState(initialStateId)) {
             throw new IllegalArgumentException(getClass()+" cannot find Initial state \'"+ 
                     initialStateId+"\' in state machine.");
@@ -923,6 +926,12 @@ public void defineTerminateEvent(E terminateEvent) {
         checkState();
         this.terminateEvent = terminateEvent;
     }
+
+    @Override
+    public void defineDefaultInitialState(S stateId) {
+        checkState();
+        this.defaultInitStateId = stateId;
+    }
 
     void setScanAnnotations(boolean isScanAnnotations) {
         this.isScanAnnotations = isScanAnnotations;

squirrel-foundation/src/main/java/org/squirrelframework/foundation/fsm/impl/StateMachineImporterImpl.java

@@ -61,7 +61,9 @@ public class StateMachineImporterImpl<T extends StateMachine<T, S, E, C>, S, E,
             ArrayListMultimap.create();
 
     protected Boolean isEntryAction;
-
+
+    protected String initStateIdName;
+
     protected final Map<String, Object> reusableInstance = Maps.newHashMap();
 
     public StateMachineImporterImpl() {
@@ -138,6 +140,8 @@ public void startElement(String uri, String localName, String qName,
 
             currentStates.clear();
             currentTranstionBuilder=null;
+
+            stateMachineBuilder.defineDefaultInitialState(stateConverter.convertFromString(initStateIdName));
         } else if(qName.equals("state") || qName.equals("final") || qName.equals("parallel")) {
             MutableState<T, S, E, C> parentState = null;
             if(currentStates.size()>0) {
@@ -252,6 +256,8 @@ public void startElement(String uri, String localName, String qName,
             } else if(condSchema.equals("mvel")) {
                 getCurrentTranstionBuilder().whenMvel(condContent);
             }
+        } else if (qName.equals("scxml")) {
+            this.initStateIdName = attributes.getValue("initial");
         }
     }
 

squirrel-foundation/src/test/java/org/squirrelframework/foundation/fsm/DefaultInitialStateTest.java

@@ -0,0 +1,47 @@
+package org.squirrelframework.foundation.fsm;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.squirrelframework.foundation.fsm.impl.AbstractStateMachine;
+
+public class DefaultInitialStateTest {
+    private StateMachineBuilder<DefaultInitialStateMachine, TestState, TestEvent, Void> builder;
+
+    @Before
+    public void setUp() throws Exception {
+        builder = StateMachineBuilderFactory.create(DefaultInitialStateMachine.class, TestState.class, TestEvent.class, Void.class);
+        builder.defineDefaultInitialState(TestState.A);
+        builder.transition().from(TestState.A).to(TestState.B).on(TestEvent.ToB);
+        builder.transition().from(TestState.B).to(TestState.C).on(TestEvent.ToC);
+    }
+
+    @Test
+    public void defineInitialState() {
+        // define the initial state by builder.newStateMachine
+        DefaultInitialStateMachine initWithA = builder.newStateMachine(TestState.A);
+        Assert.assertEquals(TestState.A, initWithA.getInitialState());
+        initWithA.fire(TestEvent.ToB);
+        Assert.assertEquals(TestState.B, initWithA.getCurrentState());
+
+        // define the initial state by builder.defineInitialStateId
+        DefaultInitialStateMachine initWithDefault = builder.newStateMachine(null);
+        Assert.assertEquals(TestState.A, initWithDefault.getInitialState());
+        initWithDefault.fire(TestEvent.ToB);
+        Assert.assertEquals(TestState.B, initWithDefault.getCurrentState());
+    }
+
+    @Test
+    public void exportAndImport() {
+        DefaultInitialStateMachine stateMachine = builder.newStateMachine(null);
+        String sqrlScxml = stateMachine.exportXMLDefinition(true);
+        System.out.println(sqrlScxml);
+
+        UntypedStateMachineBuilder builder = new UntypedStateMachineImporter().importDefinition(sqrlScxml);
+        DefaultInitialStateMachine recover = builder.newAnyStateMachine(null);
+        Assert.assertEquals(TestState.A, recover.getInitialState());
+    }
+
+    static class DefaultInitialStateMachine extends AbstractStateMachine<DefaultInitialStateMachine, TestState, TestEvent, Void> {
+    }
+}