Is there anyway in EF to have before update values of object?
e.g. When entity object let's say User is saved, i would like to know for logging purpose before update User object values.
Thanks,
If you work with ObjectContext (edmx) you can subscribe to the SavingChanges event.
context.SavingChanges += context_SavingChanges;
This gives access to the original and current values when SaveChanges() is executed:
private void context_SavingChanges (object sender, EventArgs e)
{
ObjectContext context = sender as ObjectContext;
if (context != null)
{
foreach (ObjectStateEntry entry in context.ObjectStateManager
.GetObjectStateEntries(EntityState.Modified))
{
// TODO: do some logging with these values.
entry.OriginalValues;
entry.CurrentValues;
}
}
}
If you work with DbContext you can get to the event by
((IObjectContextAdapter)this).ObjectContext.SavingChanges
Related
I'm trying to do the Mockito for a method called generateToken() by using MockitoJUnitRunner.class. The source which I have tried to do as follows.
#RunWith(MockitoJUnitRunner.class)
public class LoginServiceTest {
#Mock
private UserRepository userRepository;
#Mock
private JwtTokenGenerator jwtTokenGenerator;
#InjectMocks
private LoginServiceImpl loginServiceImpl = new LoginServiceImpl();
private JwtUserDto user;
private String jwtSecret;
private String username;
private String password;
/**
* Initialize test data before test cases execution
*/
#Before
public void init() {
user = new JwtUserDto();
user.setId(1L);
user.setUsername("kray1");
user.setRole("Admin");
}
#Test
public void testLogin() {
try {
Mockito.when(jwtTokenGenerator.generateToken(user, jwtSecret)).thenReturn("myToken");
String actual = loginServiceImpl.login(username, password);
assertNotNull(actual);
} catch (Exception e) {
e.printStackTrace();
}
}
For that generateToken() method, I have to pass user object and a string. I'm declaring the user object in Init() method. When I try to execute this, the value return from the login method is null. But when I try to pass the user object as null then it will work as expected. So the problem should be with the user object.
Is there anything, like Mockito is blocking this kind of object with added properties or related thing? Please help to find a way to pass this user object with Mockito.
The LoginServiceImpl class as follows.
public class LoginServiceImpl implements LoginInterface {
#Autowired
private UserRepository userRepository;
#Autowired
private JwtTokenGenerator jwtTokenGenerator;
/*
* (non-Javadoc)
*/
public String login(String userName, String password) {
if (userName != null && password != null && !userName.isEmpty() && !password.isEmpty()) {
List<UserAuthenticationInfo> authInfo = userRepository.findUserRolesByUsernamePassword(userName, password);
if (authInfo != null && !authInfo.isEmpty()) {
JwtUserDto user = new JwtUserDto();
user.setId((long) authInfo.get(0).getUserId());
user.setUsername(userName);
user.setRole(authInfo.get(0).getUserRole());
return jwtTokenGenerator.generateToken(user, jwtSecret);
}
}
return null;
}
}
Do you have equals/hashcode on User class?
What is the result if you setup mock using
Mockito.when(jwtTokenGenerator.generateToken(any(User.class),any(String.class))
.thenReturn("myToken");
explanation:
When setting expectation as
Mockito.when(jwtTokenGenerator.generateToken(user, jwtSecret)).then...
You instruct your mock to act only for given user object. equals method is used for that. So, if your User is missing equals method, then reference equality is used. Two User objects (each crated with separate new User() call will not be equal.
For non-matching parameters in Mockito.when your mock (thenReturn) is not applied. Default value (null) is returned from mock.
Therefore I prefer to setup mocks not for specific arguments and then use Mockito.verify to check if expected interactions with mock took place. That way your tests are more expressive. Actually most of my object have equals/hashode not because of business reasons (I do not put them in collections) but only for testing and comparing using assertEquals.
Side note:
do not catch (Exception e) { e.printStackTrace(); } in test. It is much easier just to declare test method to throw Exception. End result is same (stacktrace printed) but with less code.
You are probably creating a new JwtUserDto() in your production code or getting the user instance from another mock. If you haven't overwritten the equals() method in your JwtUserDto class your 'test' user won't equal the 'production' user.
Make sure that the production and test user are the same instance or that they .equals each other.
I have method execute() which calls saveCom() which is requires_new method and commits data and same is then retrieved below by calling saveCom somehow I am not able retrieve the data
#Async
#Transactional
public void execute(){
commService.saveCom(comm);//this is a Requires_New method.Data gets ccommmited here
List<Comm> commList = commDao.getComm(comm);
}
//get is used then to retrieve the data
public List<Comm> getCom(Comm comm) throws PimsAppException {
List<Comm> restriction_list = new ArrayList<Comm>();
try {
Object[] updateObjs = new Object[]{comm.getCommId(),comm.getCountryofDestination(),
comm.getPortOfEntry()};
restriction_list = jdbcTemplate.query("" SELECT * FROM pims.pdcommrestriction WHERE ( commodityid = ? AND countryofdestination = ? AND portofentry = ? ),updateObjs,new CommMapper());
}
catch (Throwable e) {
Logger.getLogger().error("Class=CommImpl; Method=getComm "+e);
}
return restriction_list;
}
After saveCom method is executed,i can see that data has been inserted into the DB but when I try to retrieve the data in the next line by calling getComm().It is not able to retrieve the data.....
Is there any issue with jdbctemplate not able to retrieve the data after data has been commited above using Requires_NEW?
UPDATE:
If I remove the #Transactional on execute,getCom is able to retrieve the data
Following the directions from many articles, I've decided to implement the Unit of work pattern to my Linq2SQL DataContexts in my ASP.Net WebForms Application, but I'm not sure if I'm on the right way.
Here's what I'm accomplishing so far:
1 - On every Request, I catch the Application_AcquireRequestState event (which has access to Session data) in Global.asax and instantiate a new DataContext to bind it to the user's Session:
void Application_AcquireRequestState(object sender, EventArgs e)
{
// Check if the request is for a Page, Page Method or Handler
if (new Regex(#"\.(aspx|ashx)(/.*)?$").IsMatch(HttpContext.Current.Request.Url.AbsolutePath))
{
MyCompany.MyDatabaseDataContext myDatabaseDataContext = new MyCompany.MyDatabaseDataContext();
HttpContext.Current.Session["myDatabaseDataContext"] = myDatabaseDataContext;
}
}
2 - Every Data Access Layer Object (DAO) inherits from a base DAO: GenericDAO:
public class GenericDAO
{
private MyDatabaseDataContext _dbMyDatabase;
protected MyDatabaseDataContext dbMyDatabase
{
get
{
if (_dbMyDatabase == null)
_dbMyDatabase = HttpContext.Current.Session["myDatabaseDataContext"] as MyDatabaseDataContext;
return _dbMyDatabase;
}
}
}
3 - So, in every operation, the DAO use the DataContext Property from its parent class:
public class MyTableDAO : GenericDAO
{
public List<MyTable> getAll()
{
return dbMyDatabase.GetTable<MyTable>().ToList();
}
}
Here's my concerns...
First of all, is it ok to store the DataContext in the user's Session? What would be another option? My app has a lot of PageMethods calls, so I'm worried the DTX would be invalidated between their async requests if it is stored in the session.
Do I need to capture the Application_ReleaseRequestState event to Dispose() of the DataContext and remove it from the session?
If I don't need to Dispose of it, in every Application_AcquireRequestState, would it be better to Remove DTX from Session - Create DTX - Store it or just Refresh it?
Also, if I don't need to Dispose of it, what about Connections? Would it handle them automatically or I would need to control them too?
I appreciate your time and help :)
-- EDIT
Here's the code I've reached, following #ivowiblo's suggestion:
Global.asax
void Application_BeginRequest(object sender, EventArgs e)
{
if (new Regex(#"\.(aspx|ashx)(/.*)?$").IsMatch(HttpContext.Current.Request.Url.AbsolutePath))
{
MyCompany.MyDatabaseDataContext myDatabaseDataContext = new MyCompany.MyDatabaseDataContext();
HttpContext.Current.Items["myDatabaseDataContext"] = ceabsDataContext;
}
}
void Application_EndRequest(object sender, EventArgs e)
{
if (new Regex(#"\.(aspx|ashx)(/.*)?$").IsMatch(HttpContext.Current.Request.Url.AbsolutePath))
{
if (HttpContext.Current.Items["myDatabaseDataContext"] != null)
{
System.Data.Linq.DataContext myDbDtx = HttpContext.Current.Items["myDatabaseDataContext"] as System.Data.Linq.DataContext;
if (myDbDtx != null)
myDbDtx.Dispose();
}
}
}
GenericDAO
public class GenericDAO
{
protected MyDatabaseDataContext dbMyDatabase
{
get
{
return HttpContext.Current.Items["myDatabaseDataContext"] as MyDatabaseDataContext;
}
}
}
Simple as that!
The best approach is to put it on HttpContext.Current.Items, creating the DataContext on RequestBegin and dispose it in RequestEnd. In msdn there's an interesting article about the better management of the DataContext, where it's suggested to have short-time DataContext instances.
This pattern is called Open session in view and was created for using NHibernate in web environments.
You say you are implementing unit-of-work, but by storing it in the cache you do not really stick to that unit-of-work.
My advice is to create a new DataContext for every request and not to cache it anyware.
I spend most of my time in C# and am trying to figure out which is the best practice for handling an exception and cleanly return an error message from a called method back to the calling method.
For example, here is some ActiveDirectory authentication code. Please imagine this Method as part of a Class (and not just a standalone function.)
bool IsUserAuthenticated(string domain, string user, string pass, out errStr)
{
bool authentic = false;
try
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
// No exception thrown? We must be good, then.
authentic = true;
}
catch (Exception e) { errStr = e.Message().ToString(); }
return authentic;
}
The advantages of doing it this way are a clear YES or NO that you can embed right in your If-Then-Else statement. The downside is that it also requires the person using the method to supply a string to get the Error back (if any.)
I guess I could overload this method with the same parameters minus the "out errStr", but ignoring the error seems like a bad idea since there can be many reasons for such a failure...
Alternatively, I could write a method that returns an Error String (instead of using "out errStr") in which a returned empty string means that the user authenticated fine.
string AuthenticateUser(string domain, string user, string pass)
{
string errStr = "";
try
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
}
catch (Exception e) { errStr = e.Message().ToString(); }
return errStr;
}
But this seems like a "weak" way of doing things.
Or should I just make my method "void" and just not handle the exception so that it gets passed back to the calling function?
void AuthenticateUser(string domain, string user, string pass)
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
}
This seems the most sane to me (for some reason). Yet at the same time, the only real advantage of wrapping those 2 lines over just typing those 2 lines everywhere I need to authenticate is that I don't need to include the "LDAP://" string. The downside with this way of doing it is that the user has to put this method in a try-catch block.
Thoughts?
Is there another way of doing this that I'm not thinking of?
There is no "one size fits all". If you return a flag, that makes it easy to use a method in if() and loops. Exceptions always need a lot of boiler plate code. If you just want a string which you can display to the user (say, in a web UI), returning the error string (or null for "no error") is good, too.
But most of the time, I throw an exception (and in Java a subclass of RuntimeException) because that allows me to return more than a single information about the error (like: Which file caused the error? Which line/column? What was I doing? Which field in a form should be marked as illegal? etc).
In your case, you can't handle the exception in your method, so you shouldn't catch it. Only catch it when you can do something about it.
In this example, I agree, you should let the exception flow through to the consumer. However, as an alternative to the approaches you highlighted, consider this approach.
You can use a response object to hold information coming out of a method run, for example:
public abstract class BaseResponse
{
public bool IsOk { get; protected set;}
public string Message { get; protected set; }
}
public class AuthenticationResponse: BaseResponse
{
public AuthenticationResponse(bool isOk): this(isOk, "") {}
public AuthenticationResponse(bool isOk, string message)
{
IsOk = isOk;
Message = message;
}
}
AuthenticationResponse IsUserAuthenticated(string domain, string user, string pass)
{
bool authentic = false;
string errStr;
try
{
// Instantiate Directory Entry object
DirectoryEntry entry = new DirectoryEntry("LDAP://" + domain, user, pass);
// Force connection over network to authenticate
object nativeObject = entry.NativeObject;
// No exception thrown? We must be good, then.
authentic = true;
}
catch (Exception e) { errStr = e.Message().ToString(); }
return new AuthenticationResponse(authentic, errStr);
}
Then to use it in your if statements:
AuthenticationResponse response;
if((response = IsUserAuthenticated("domain", "user", "pass")).IsOk)
{
// do successful activity
} else {
Console.WriteLine(response.Message)
}
The trick is the return value of an assignment operation is the value that was assigned. So, we can do the assignment and the valid check in the same line. If you didn't need to hold onto the result of the call, you could simply call the method and check the IsOk property.
if(IsUserAuthenticated("domain", "user", "pass").IsOk)
{
// do successful activity
}
Then you can build up your custom response object to return any combination of values from your method as you need.
Don't handle the exception or return a message of any kind. Let the consumer of your method take care of this.
I just started using LINQ to SQL classes, and really like how this helps me write readable code.
In the documentation, typical examples state that to do custom validation, you create a partial class as so::
partial class Customer
{
partial void OnCustomerIDChanging(string value)
{
if (value=="BADVALUE") throw new NotImplementedException("CustomerID Invalid");
}
}
And similarly for other fields...
And then in the codebehind, i put something like this to display the error message and keep the user on same page so to correct the mistake.
public void CustomerListView_OnItemInserted(object sender, ListViewInsertedEventArgs e)
{
string errorString = "";
if (e.Exception != null)
{
e.KeepInInsertMode = true;
errorString += e.Exception.Message;
e.ExceptionHandled = true;
}
else errorString += "Successfully inserted Customer Data" + "\n";
errorMessage.Text = errorString;
}
Okay, that's easy, but then it stops validating the rest of the fields as soon as the first Exception is thrown!! Mean if the user made mode than one mistake, she/he/it will only be notified of the first error.
Is there another way to check all the input and show the errors in each ?
Any suggestions appreciated, thanks.
This looks like a job for the Enterprise Library Validation Application Block (VAB). VAB has been designed to return all errors. Besides this, it doesn't thrown an exception, so you can simply ask it to validate the type for you.
When you decide to use the VAB, I advise you to -not- use the OnXXXChanging and OnValidate methods of LINQ to SQL. It's best to override the SubmitChange(ConflictMode) method on the DataContext class to call into VAB's validation API. This keeps your validation logic out of your business entities, which keeps your entities clean.
Look at the following example:
public partial class NorthwindDataContext
{
public ValidationResult[] Validate()
{
return invalidResults = (
from entity in this.GetChangedEntities()
let type = entity.GetType()
let validator = ValidationFactory.CreateValidator(type)
let results = validator.Validate(entity)
where !results.IsValid
from result in results
select result).ToArray();
}
public override void SubmitChanges(ConflictMode failureMode)
{
ValidationResult[] this.Validate();
if (invalidResults.Length > 0)
{
// You should define this exception type
throw new ValidationException(invalidResults);
}
base.SubmitChanges(failureMode);
}
private IEnumerable<object> GetChangedEntities()
{
ChangeSet changes = this.GetChangeSet();
return changes.Inserts.Concat(changes.Updates);
}
}
[Serializable]
public class ValidationException : Exception
{
public ValidationException(IEnumerable<ValidationResult> results)
: base("There are validation errors.")
{
this.Results = new ReadOnlyCollection<ValidationResult>(
results.ToArray());
}
public ReadOnlyCollection<ValidationResult> Results
{
get; private set;
}
}
Calling the Validate() method will return a collection of all errors, but rather than calling Validate(), I'd simply call SubmitChanges() when you're ready to persist. SubmitChanges() will now check for errors and throw an exception when one of the entities is invalid. Because the list of errors is sent to the ValidationException, you can iterate over the errors higher up the call stack, and present them to the user, as follows:
try
{
db.SubmitChanges();
}
catch (ValidationException vex)
{
ShowErrors(vex.ValidationErrors);
}
private static void ShowErrors(IEnumerable<ValidationResult> errors)
{
foreach(var error in errors)
{
Console.WriteLine("{0}: {1}", error.Key, error.message);
}
}
When you use this approach you make sure that your entities are always validated before saving them to the database
Here is a good article that explains how to integrate VAB with LINQ to SQL. You should definitely read it if you want to use VAB with LINQ to SQL.
Not with LINQ. Presumably you would validate the input before giving it to LINQ.
What you're seeing is natural behaviour with exceptions.
I figured it out. Instead of throwing an exception at first failed validation, i store an error message in a class with static variable. to do this, i extend the DataContext class like this::
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
/// <summary>
/// Summary description for SalesClassesDataContext
/// </summary>
public partial class SalesClassesDataContext
{
public class ErrorBox
{
private static List<string> Messages = new List<string>();
public void addMessage(string message)
{
Messages.Add(message);
}
public List<string> getMessages()
{
return Messages;
}
}
}
in the classes corresponding to each table, i would inherit the newly defined class like this::
public partial class Customer : SalesClassesDataContext.ErrorBox
only in the function OnValidate i would throw an exception in case the number of errors is not 0. Hence not attempting to insert, and keeping the user on same input page, without loosing the data they entered.