#60 First crack at PathHelper for java config

validation/src/main/java/org/springjutsu/validation/dsl/PathHelper.java

@@ -0,0 +1,67 @@
+package org.springjutsu.validation.dsl;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.lang.reflect.ParameterizedType;
+import java.util.Collection;
+
+import org.apache.commons.lang.StringUtils;
+import org.springframework.cglib.proxy.Enhancer;
+import org.springframework.cglib.proxy.InvocationHandler;
+
+/**
+ * Will generate dynamic proxies along a call chain. Does not support
+ * abstract/final types. Does not support classes with no default constructor.
+ * Internally, overrides the toString method on each proxy to return the current path.
+ * @author twicksell
+ *
+ */
+public class PathHelper {
+
+	public static <T> T forEntity(Class<T> clazz)
+	{
+		return forEntity(clazz, "", null);
+	}
+
+	protected static <T> T forEntity(Class<T> clazz, String path, Class parameterizedType)
+	{
+		Enhancer enhancer = new Enhancer();
+		return (T) enhancer.create(clazz, new PathBuildingInvocationHandler(path, parameterizedType));
+	}
+
+
+}
+
+class PathBuildingInvocationHandler extends PathHelper implements InvocationHandler
+{
+
+	String path;
+	Class parameterizedType;
+	public PathBuildingInvocationHandler(String path, Class parameterizedType) {
+		this.path=path;
+		this.parameterizedType=parameterizedType;
+	}
+	@Override
+	public Object invoke(Object proxy, Method method, Object[] arguments) throws Throwable {
+		Class returnType = (parameterizedType != null) ? parameterizedType : method.getReturnType();
+		Class parameterType = null;
+		if(method.getName().equals("toString"))
+			return path;
+		if(Collection.class.isAssignableFrom(method.getReturnType()))
+		{
+			parameterType = Class.forName(((ParameterizedType)method.getGenericReturnType()).getActualTypeArguments()[0].getTypeName());
+		}
+
+
+		if(!path.isEmpty() && parameterizedType == null)
+			path+=".";
+		path+=StringUtils.uncapitalize(method.getName().replace("get", ""));
+		if(method.getReturnType().equals(String.class))
+			return path;
+		if(Modifier.isFinal(method.getReturnType().getModifiers()))
+			throw new RuntimeException("Cannot help with final or abstract return types: "+method.getReturnType());
+
+		return PathHelper.forEntity(returnType, path, parameterType);
+	}
+
+}

validation/src/main/java/org/springjutsu/validation/dsl/Validation.java

@@ -20,13 +20,22 @@ public static ValidationRuleBuilder rule(String path, String type)
 				.forPath(path).usingHandler(type).behaviorOnFail(RuleErrorMode.ERROR);
 	}
 
+	public static ValidationRuleBuilder rule(Object path, String type)
+	{
+		return rule(path.toString(), type);
+	}
+
 	public static <M,A> ValidationRuleBuilder rule(String path, String message, RuleExecutor<M,A> handlerImpl)
 	{
 		return ReflectionBuilder.implementationFor(ValidationRuleBuilder.class)
 				.usingAttributeAccessStrategy(new OverloadedPropertyAwareSetterAttributeAccessStrategy()).create()
 				.forPath(path).withMessage(message).usingHandler(handlerImpl).behaviorOnFail(RuleErrorMode.ERROR);
 	}
 
+	public static <M,A> ValidationRuleBuilder rule(Object path, String message, RuleExecutor<M,A> handlerImpl)
+	{
+		return rule(path.toString(), message, handlerImpl);
+	}
 	public static ValidationContextBuilder context(String type, String... qualifiers)
 	{
 		return ReflectionBuilder.implementationFor(ValidationContextBuilder.class)

validation/src/test/java/org/springjutsu/validation/ValidationJavaConfigurationIntegrationTest.java

@@ -9,6 +9,7 @@
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.validation.Errors;
+import org.springjutsu.validation.dsl.PathHelper;
 import org.springjutsu.validation.dsl.Validation;
 import org.springjutsu.validation.executors.impl.RequiredRuleExecutor;
 import org.springjutsu.validation.rules.ValidationEntity;
@@ -68,7 +69,7 @@ ValidationEntity personValidation()
 							Validation.rule("lastName", "required").withMessage("dizzam"),
 							Validation.rule("address", "required").withMessage("doh")
 							.havingValidationContexts(Validation.group("buster")
-								.havingRules(Validation.rule("address.lineOne", "required").withMessage("p-p-p-pow")))
+								.havingRules(Validation.rule(PathHelper.forEntity(Customer.class).getAddress().getLineOne(), "required").withMessage("p-p-p-pow")))
 							))
 				.build();
 

validation/src/test/java/org/springjutsu/validation/dsl/PathHelperTest.java

@@ -0,0 +1,19 @@
+package org.springjutsu.validation.dsl;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.springjutsu.validation.test.entities.Company;
+import org.springjutsu.validation.test.entities.Customer;
+
+public class PathHelperTest {
+
+	@Test
+	public void test()
+	{
+		Assert.assertEquals("address", PathHelper.forEntity(Customer.class).getAddress().toString());
+		Assert.assertEquals("address.lineOne", PathHelper.forEntity(Customer.class).getAddress().getLineOne());
+		Assert.assertEquals("customers.firstName", PathHelper.forEntity(Company.class).getCustomers().get(0).getFirstName());
+		Assert.assertEquals("customers", PathHelper.forEntity(Company.class).getCustomers().toString());
+	}
+
+}