I am using serenity BDD for my automation testing and Page Object Model for my framework. I have created a BasePage class which will be inherited by all the other Pages. I want to minimize the logging messages from the Pages by adding all the log.info messages to a central Base page. Example, when calling the click() method, I will log before click and after click methods as shown below in the basePage class:
public class BasePage extends PageObject{
private static final Logger log = LogManager.getLogger(BasePage.class.getClass());
private final WebElementFacade element;
public static void clickBtn(WebElementFacade btnName) {
log.info("About to click " + btnName + " button");
btnName.click();
log.info("Successfully clicked on " + btnName + " button.");
}
Later I figured that instead of individually trying to figure out in advance what actions the user will perform on the webElements, and write new methods for each action (like the one shown above), just implement WebDriverFacade interface, so that I get all the unimplemented method list in BasePage from WebDriverFacade and then write the log messages inside each of them, like so:
public class BasePage extends PageObject implements WebElementFacade{
private static final Logger log = LogManager.getLogger(BasePage.class.getClass());
private final WebElementFacade element;
#Override
public void submit() {
// TODO Auto-generated method stub
}
#Override
public void sendKeys(CharSequence... keysToSend) {
// TODO Auto-generated method stub
}
#Override
public String getTagName() {
// TODO Auto-generated method stub
return null;
}
#Override
public boolean isSelected() {
// TODO Auto-generated method stub
return false;
}
.
.
.
.
.
}
This will serve two purposes:
I will not have to create new methods for every action in BasePage class, example the 'clickBtn()' function in the first code
As I mentioned before, I will not have to figure out what method any other person who adds methods to my code might use and having to change the BasePage class to create the new actions. So basically less maintenance in the long run.
The problem I am facing is an error that I receive in the second use case:
The return types are incompatible for the inherited methods WebElementFacade.withTimeoutOf(int, TimeUnit), PageObject.withTimeoutOf(int, TimeUnit)
Now my question is:
How can solve this problem?
Is this the right way to do things or should I be going with the first method and have maintenance overhead.
Just figured that another scenario where this might be useful. To make sure that subclass methods do not use methods from pageObject and are forced to use the methods from BaseClass only. This can be done by wrapping the WebElementFacade and adding the log messages as an added functionality. Any thought on this would be appreciated.
Thank you!
Honestly it is a neat trick and if you get it working you should be proud.
I think I figured something similar out in a dynamic language.
But you are better off just adding the logging entries and learning the following.
How to name functions so you don't feel like they need renaming.
How to log clearly for debugging use.
This is because loggings power is in its flexibility.
When you learn how to dump something complex like a matrix so you can eye it and go uh-oh you are increasing your overall skills.
I apologize for not giving you code but I felt some "chase the other rabbit" advice was better.
We have implemented several custom ORM objects in our webshop implementation that have references (dependencies) to Intershop Product system object.
When a user tries to delete a certain product in back-office, it causes problems because references to that product may still exist in our custom objects. Naturally, deleting a product that is referenced from one of our custom objects generates an exception like this:
java.sql.SQLTransactionRollbackException: ORA-02091: transaction rolled back ORA-02292: integrity constraint (INTERSHOP.A1POSTPAIDPRICE_CO_002) violated - child record found
We have figured that we could solve that by implementing an ORMObjectListener and overriding objectDeleting method to delete all the references before the product actually gets deleted.
Intershop cookbook for ORM layer states:
"Instances must implement the interface ORMObjectListener for a given ORM object type and register at the factory. The listener is called when instances of the given type are created, changed or removed."
(https://support.intershop.com/kb/index.php/Display/2G3270#Cookbook-ORMLayer-Recipe:NotificationofPersistentObjectChanges)
However, we cannot find a cookbook for registering the listener at the factory. What do we need to do to register the listener?
Also, if there is some better way for handling dependencies to system objects on our custom objects during delete event, I'm open to suggestions.
UPDATE:
This is the listener class I have tried with so far:
public class ProductDeleteListener implements ORMObjectListener<ProductPO> {
#Inject
ProductPOFactory productPOFactory;
/** The Constant LOGGER. */
private static final Logger LOGGER = LoggerFactory.getLogger(ProductDeleteListener.class);
public ProductDeleteListener() {
productPOFactory.addObjectListener(this, new AttributeDescription[0]);
}
#Override
public boolean isOldStateNeeded() {
// TODO Auto-generated method stub
return false;
}
#Override
public void objectChanged(ProductPO object, Map<AttributeDescription, Object> previousValues) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("PRODUCT LISTENER TEST - CHANGE");
}
}
#Override
public void objectChanging(ProductPO object, Map<AttributeDescription, Object> previousValues) {
// TODO Auto-generated method stub
}
#Override
public void objectCreated(ProductPO object) {
// TODO Auto-generated method stub
}
#Override
public void objectCreating(ProductPO object) {
// TODO Auto-generated method stub
}
#Override
public void objectDeleted(ORMObjectKey objectKey) {
// TODO Auto-generated method stub
}
#Override
public void objectDeleting(ProductPO object) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("PRODUCT LISTENER TEST - PRE DELETE");
}
}
}
But it is not working. Nothing gets logged when object changes or gets deleted.
In addition to what Willem Evertse wrote you need to place your registration code in a class that gets instantiated via Intershop Component Framework.
implementation.component:
<components xmlns="http://www.intershop.de/component/2010" scope="global">
<implementation name="ProductDeleteListenerRegistrar"
class="your.fullqualifed.ProductDeleteRegistrar" start="start" stop="stop"></implementation>
instances.component:
<components xmlns="http://www.intershop.de/component/2010"> <instance name="ORMValidator" with="ORMValidator" scope="global"/></components>
You need to write a class, e.g. ProductDeleteRegistrar and provide start method in which you can add registration calls like Willem described. As for stop method you need to safely unregister your object listener. Make sure both methods are declared to be synchronized.
I think registering a listen would be the right approach. Maybe just look out for performance problems.
You are right that there are no examples of this, but here is an example.
Get the factory that you want to receive messages from. In your case, it is ProductPOFactory
ProductPOFactory productFactory = (ProductPOFactory) NamingMgr.getInstance().lookupFactory(ProductPO.class);
productFactory.addObjectListener(new MyProductChangeListener());
MyProductChangeListener needs to extend AbstractORMObjectListener<ProductPO>
and implement the method public void objectDeleting(T object)
Every time a product gets deleted your listener should be called and then you can clean up your custom orm objects. You can have a look at ImageSetDefinitionPOListener as an example
Ok, so I have asked another question on the same topic here and while I did not get a direct answer there I've pulled together some code that I got working to do what I wanted. Question is, does this way break some OOP principle?
What I wanted
Use proper OOP to declare fault types on a service
Have one catch block in the client side that can handle multiple types of exceptions thrown from the service
Have one HandleException method per fault class that has its own implementation
On the client side have just one exception block understand what exception was thrown and call the respective HandleException method from the corresponding fault class
How I got it working
Declared a fault contract on server for each exception type that inherits from a base exception type
[DataContract]
public class BusinessRuleViolationFault : BaseFault
{
public BusinessRuleViolationFault(string message)
: base(message)
{
}
}
[DataContract]
public class SomeOtherViolationFault : BaseFault
{
public SomeOtherViolationFault(string message)
: base(message)
{
}
}
[DataContract]
public abstract class BaseFault
{
public BaseFault(string message)
{
Message = message;
}
}
On the client side I created partial classes of the same fault types as above and implemented the handle exception method in it. I had to do this on the client side since if I created this method on the service side it would not get serialized and be available via the proxy.
public partial class BusinessRuleViolationFault : BaseFault
{
public override void HandleException()
{
MessageBox.Show("BusinessRuleViolationFault handled");
}
}
public partial class SomeOtherViolationFault : BaseFault
{
public override void HandleException()
{
MessageBox.Show("SomeOtherViolationFault handled");
}
}
public abstract partial class BaseFault
{
public abstract void HandleException();
}
Then created an extension method on the faultexception class as per Christians code which I have marked as accepted answer in my previous post. This basically used reflection to get me the name of the fault exception class that was thrown.
Then in my client catch block I used that name to create an instance of the locally created partial class which has the handle exception method.
What I am curious to know is, have I broken some OOP principle here?
Is this OOP at all?
I dont want multiple if else statement in this one catch block or have multiple catch blocks. What is your opinion on the tradeoff of using one catch block to gain performance and lose it with reflection by trying to figure out what class method to call?
Thanks for your time and patience ...
I don't understand exactly why reflection is needed here (as described in the previous posted question). I simply do this in my code and it works fine:
try
{
proxy.CallServiceMethod(message);
}
catch (Exception e)
{
if (e is FaultException<BaseFault>)
{
BaseFault exceptionToHandle =
(e as FaultException<BaseFault>).Detail as BaseFault;
exceptionToHandle.HandleException();
}
}
Aside from the unnecessary reflection, I don't see anything wrong with the way you have implemented this (from an OOP point of view at least).
I implemented a class that implements IErrorHandler interface to log WCF errors. One of the things that I'd like to do is log who the identity of the user than connected to my service when an exception occurred. All my logging occurs in HandleError() method of IErrorHandler interface, but since HandleError() may not have current operation context, I can't get the SecurityContext.PrimaryIdentity. I've come up with the following code to capture things that may not be available in HandleError method, but I'm not sure this will work in all cases.
public class MyErrorHandler : IErrorHandler
{
private IIdentity identity;
public bool HandleError(Exception error)
{
// Do something with identity
return false;
}
public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
this.identity = Operation.Current.SecurityContext.PrimaryIdentity;
}
}
The code above seems to be working, but are there any gotchas?
Thanks!
For some reason, I thought that the class was created every time there was an exception. In any case, I was able to solve my issue by using Dictionary property of Exception object to store custom data that I wanted to log with my exception.
I am researching Prism v2 by going thru the quickstarts. And I have created a WCF service with the following signature:
namespace HelloWorld.Silverlight.Web
{
[ServiceContract(Namespace = "http://helloworld.org/messaging")]
[AspNetCompatibilityRequirements(RequirementsMode =
AspNetCompatibilityRequirementsMode.Allowed)]
public class HelloWorldMessageService
{
private string message = "Hello from WCF";
[OperationContract]
public void UpdateMessage(string message)
{
this.message = message;
}
[OperationContract]
public string GetMessage()
{
return message;
}
}
}
When I add a service reference to this service in my silverlight project it generates an interface and a class:
[System.ServiceModel.ServiceContractAttribute
(Namespace="http://helloworld.org/messaging",
ConfigurationName="Web.Services.HelloWorldMessageService")]
public interface HelloWorldMessageService {
[System.ServiceModel.OperationContractAttribute
(AsyncPattern=true,
Action="http://helloworld.org/messaging/HelloWorldMessageService/UpdateMessage",
ReplyAction="http://helloworld.org/messaging/HelloWorldMessageService/UpdateMessageResponse")]
System.IAsyncResult BeginUpdateMessage(string message, System.AsyncCallback callback, object asyncState);
void EndUpdateMessage(System.IAsyncResult result);
[System.ServiceModel.OperationContractAttribute(AsyncPattern=true, Action="http://helloworld.org/messaging/HelloWorldMessageService/GetMessage", ReplyAction="http://helloworld.org/messaging/HelloWorldMessageService/GetMessageResponse")]
System.IAsyncResult BeginGetMessage(System.AsyncCallback callback, object asyncState);
string EndGetMessage(System.IAsyncResult result);
}
public partial class HelloWorldMessageServiceClient : System.ServiceModel.ClientBase<HelloWorld.Core.Web.Services.HelloWorldMessageService>, HelloWorld.Core.Web.Services.HelloWorldMessageService {
{
// implementation
}
I'm trying to decouple my application by passing around the interface instead of the concrete class. But I'm having difficulty finding examples of how to do this. When I try and call EndGetMessage and then update my UI I get an exception about updating the UI on the wrong thread. How can I update the UI from a background thread?
I tried but I get UnauthorizedAccessException : Invalid cross-thread access.
string messageresult = _service.EndGetMessage(result);
Application.Current.RootVisual.Dispatcher.BeginInvoke(() => this.Message = messageresult );
The exception is thrown by Application.Current.RootVisual.
Here is something I like doing... The service proxy is generated with an interface
HelloWorldClient : IHelloWorld
But the problem is that IHelloWorld does not include the Async versions of the method. So, I create an async interface:
public interface IHelloWorldAsync : IHelloWorld
{
void HelloWorldAsync(...);
event System.EventHandler<HelloWorldEventRgs> HelloWorldCompleted;
}
Then, you can tell the service proxy to implement the interface via partial:
public partial class HelloWorldClient : IHelloWorldAsync {}
Because the HelloWorldClient does, indeed, implement those async methods, this works.
Then, I can just use IHelloWorldAsync everywhere and tell the UnityContainer to use HelloWorldClient for IHelloWorldAsync interfaces.
Ok, I have been messing with this all day and the solution is really much more simple than that. I originally wanted to call the methods on the interface instead of the concreate class. The interface generated by proxy class generator only includes the BeginXXX and EndXXX methods and I was getting an exception when I called EndXXX.
Well, I just finished reading up on System.Threading.Dispatcher and I finally understand how to use it. Dispatcher is a member of any class that inherits from DispatcherObject, which the UI elements do. The Dispatcher operates on the UI thread, which for most WPF applications there is only 1 UI thread. There are exceptions, but I believe you have to do this explicitly so you'll know if you're doing it. Otherwise, you've only got a single UI thread. So it is safe to store a reference to a Dispatcher for use in non-UI classes.
In my case I'm using Prism and my Presenter needs to update the UI (not directly, but it is firing IPropertyChanged.PropertyChanged events). So what I have done is in my Bootstrapper when I set the shell to Application.Current.RootVisual I also store a reference to the Dispatcher like this:
public class Bootstrapper : UnityBootstrapper
{
protected override IModuleCatalog GetModuleCatalog()
{
// setup module catalog
}
protected override DependencyObject CreateShell()
{
// calling Resolve instead of directly initing allows use of dependency injection
Shell shell = Container.Resolve<Shell>();
Application.Current.RootVisual = shell;
Container.RegisterInstance<Dispatcher>(shell.Dispatcher);
return shell;
}
}
Then my presenter has a ctor which accepts IUnityContainer as an argument (using DI) then I can do the following:
_service.BeginGetMessage(new AsyncCallback(GetMessageAsyncComplete), null);
private void GetMessageAsyncComplete(IAsyncResult result)
{
string output = _service.EndGetMessage(result);
Dispatcher dispatcher = _container.Resolve<Dispatcher>();
dispatcher.BeginInvoke(() => this.Message = output);
}
This is sooooo much simpler. I just didn't understand it before.
Ok, so my real problem was how to decouple my dependency upon the proxy class created by my service reference. I was trying to do that by using the interface generated along with the proxy class. Which could have worked fine, but then I would have also had to reference the project which owned the service reference and so it wouldn't be truly decoupled. So here's what I ended up doing. It's a bit of a hack, but it seems to be working, so far.
First here's my interface definition and an adapter class for the custom event handler args generated with my proxy:
using System.ComponentModel;
namespace HelloWorld.Interfaces.Services
{
public class GetMessageCompletedEventArgsAdapter : System.ComponentModel.AsyncCompletedEventArgs
{
private object[] results;
public GetMessageCompletedEventArgsAdapter(object[] results, System.Exception exception, bool cancelled, object userState) :
base(exception, cancelled, userState)
{
this.results = results;
}
public string Result
{
get
{
base.RaiseExceptionIfNecessary();
return ((string)(this.results[0]));
}
}
}
/// <summary>
/// Create a partial class file for the service reference (reference.cs) that assigns
/// this interface to the class - then you can use this reference instead of the
/// one that isn't working
/// </summary>
public interface IMessageServiceClient
{
event System.EventHandler<GetMessageCompletedEventArgsAdapter> GetMessageCompleted;
event System.EventHandler<AsyncCompletedEventArgs> UpdateMessageCompleted;
void GetMessageAsync();
void GetMessageAsync(object userState);
void UpdateMessageAsync(string message);
void UpdateMessageAsync(string message, object userState);
}
}
Then I just needed to create a partial class which extends the proxy class generated by the service reference:
using System;
using HelloWorld.Interfaces.Services;
using System.Collections.Generic;
namespace HelloWorld.Core.Web.Services
{
public partial class HelloWorldMessageServiceClient : IMessageServiceClient
{
#region IMessageServiceClient Members
private event EventHandler<GetMessageCompletedEventArgsAdapter> handler;
private Dictionary<EventHandler<GetMessageCompletedEventArgsAdapter>, EventHandler<GetMessageCompletedEventArgs>> handlerDictionary
= new Dictionary<EventHandler<GetMessageCompletedEventArgsAdapter>, EventHandler<GetMessageCompletedEventArgs>>();
/// <remarks>
/// This is an adapter event which allows us to apply the IMessageServiceClient
/// interface to our MessageServiceClient. This way we can decouple our modules
/// from the implementation
/// </remarks>
event EventHandler<GetMessageCompletedEventArgsAdapter> IMessageServiceClient.GetMessageCompleted
{
add
{
handler += value;
EventHandler<GetMessageCompletedEventArgs> linkedhandler = new EventHandler<GetMessageCompletedEventArgs>(HelloWorldMessageServiceClient_GetMessageCompleted);
this.GetMessageCompleted += linkedhandler;
handlerDictionary.Add(value, linkedhandler);
}
remove
{
handler -= value;
EventHandler<GetMessageCompletedEventArgs> linkedhandler = handlerDictionary[value];
this.GetMessageCompleted -= linkedhandler;
handlerDictionary.Remove(value);
}
}
void HelloWorldMessageServiceClient_GetMessageCompleted(object sender, GetMessageCompletedEventArgs e)
{
if (this.handler == null)
return;
this.handler(sender, new GetMessageCompletedEventArgsAdapter(new object[] { e.Result }, e.Error, e.Cancelled, e.UserState));
}
#endregion
}
}
This is an explicit implementation of the event handler so I can chain together the events. When user registers for my adapter event, I register for the actual event fired. When the event fires I fire my adapter event. So far this "Works On My Machine".
Passing around the interface (once you have instantiated the client) should be as simply as using HelloWorldMessageService instead of the HelloWorldMessageServiceClient class.
In order to update the UI you need to use the Dispatcher object. This lets you provide a delegate that is invoked in the context of the UI thread. See this blog post for some details.
You can make this much simpler still.
The reason the proxy works and your copy of the contract does not is because WCF generates the proxy with code that "Posts" the callback back on the calling thread rather than making the callback on the thread that is executing when the service call returns.
A much simplified, untested, partial implementation to give you the idea of how WCF proxies work looks something like:
{
var state = new
{
CallingThread = SynchronizationContext.Current,
Callback = yourCallback
EndYourMethod = // assign delegate
};
yourService.BeginYourMethod(yourParams, WcfCallback, state);
}
private void WcfCallback(IAsyncResult asyncResult)
{
// Read the result object data to get state
// Call EndYourMethod and block until the finished
state.Context.Post(state.YourCallback, endYourMethodResultValue);
}
The key is the storing of the syncronizationContext and calling the Post method. This will get the callback to occur on the same thread as Begin was called on. It will always work without involving the Dispatcher object provided you call Begin from your UI thread. If you don't then you are back to square one with using the Dispatcher, but the same problem will occur with a WCF proxy.
This link does a good job of explaining how to do this manually:
http://msdn.microsoft.com/en-us/library/dd744834(VS.95).aspx
Just revisiting old posts left unanswered where I finally found an answer. Here's a post I recently wrote that goes into detail about how I finally handled all this:
http://www.developmentalmadness.com/archive/2009/11/04/mvvm-with-prism-101-ndash-part-6-commands.aspx