Add repository config guards

- Add guard to RepositoryTransition
- New GuardRepository.
- Relates to #262

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/GuardRepository.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.NoRepositoryBean;
+import org.springframework.data.repository.Repository;
+
+/**
+ * Generic {@link Repository} interface for guards.
+ *
+ * @author Janne Valkealahti
+ *
+ * @param <T> the guard entity type
+ */
+@NoRepositoryBean
+public interface GuardRepository <T extends RepositoryGuard> extends CrudRepository<T, Long> {
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryGuard.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+/**
+ * Generic interface representing guard entity.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+public interface RepositoryGuard {
+
+	/**
+	 * Gets the name.
+	 *
+	 * @return the name
+	 */
+	String getName();
+
+	/**
+	 * Gets the spel.
+	 *
+	 * @return the spel
+	 */
+	String getSpel();
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryStateMachineModelFactory.java

@@ -33,6 +33,8 @@ import org.springframework.statemachine.config.model.StateMachineModelFactory;
 import org.springframework.statemachine.config.model.StatesData;
 import org.springframework.statemachine.config.model.TransitionData;
 import org.springframework.statemachine.config.model.TransitionsData;
+import org.springframework.statemachine.guard.Guard;
+import org.springframework.statemachine.guard.SpelExpressionGuard;
 import org.springframework.statemachine.transition.TransitionKind;
 import org.springframework.util.StringUtils;
 
@@ -161,7 +163,20 @@ public class RepositoryStateMachineModelFactory extends AbstractStateMachineMode
 			}
 
 			TransitionKind kind = t.getKind();
-			transitionData.add(new TransitionData<>(t.getSource(), t.getTarget(), t.getEvent(), actions, null, kind != null ? kind : TransitionKind.EXTERNAL));
+
+			Guard<String, String> guard = null;
+			RepositoryGuard repositoryGuard = t.getGuard();
+			if (repositoryGuard != null) {
+				if (StringUtils.hasText(repositoryGuard.getName())) {
+					guard = resolveGuard(repositoryGuard.getName());
+				} else if (StringUtils.hasText(repositoryGuard.getSpel())) {
+					SpelExpressionParser parser = new SpelExpressionParser(
+							new SpelParserConfiguration(SpelCompilerMode.MIXED, null));
+					guard = new SpelExpressionGuard<>(parser.parseExpression(repositoryGuard.getSpel()));
+				}
+			}
+
+			transitionData.add(new TransitionData<>(t.getSource(), t.getTarget(), t.getEvent(), actions, guard, kind != null ? kind : TransitionKind.EXTERNAL));
 		}
 		TransitionsData<String, String> transitionsData = new TransitionsData<>(transitionData);
 

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryTransition.java

@@ -62,6 +62,13 @@ public interface RepositoryTransition {
 	 */
 	Set<? extends RepositoryAction> getActions();
 
+	/**
+	 * Gets the guard.
+	 *
+	 * @return the guard
+	 */
+	RepositoryGuard getGuard();
+
 	/**
 	 * Gets the transition kind.
 	 *