I use PersistentObject to store login and password to enter directly in the application
when I want to delete the values I use PersistentStore.destroyPersistentObject(Info.KEY);
But the values still exist. Should I add something?
To destory the persistent object you should call PersistentStore.destroyPersistentObject(key) . It can throw ControlledAccessException if the caller does not have the permission to do it. Make sure you are calling the same key you are expecting to be deleted.
Related
Swift / iOS
Can anyone tell me if it is possible to specify the PFObject objectId value when creating new objects?
I've obviously attempted but the save fails. (which might just be the answer)
The reason I am asking is I wondered if anyone had found a "trick" that would allow me to specify.
I am using PFObject.saveInBackground { method to persist the new object.
No you can not. Parse sets the objectId on the server during the save operation.
The reason your operation is failing is because Parse is looking for an object on the server with the id that you are specifying and is then trying to update that object but it cannot find the object.
RaceRegistration domain has embedded raceParticipant and raceParticipant has a field bibNumber which is Integer.
I have a method for nulling out all bibNumbers of registrations but without flush:true in save, the nulling out of bibs dont work. The bibs are not set to null.
def nullifyBibNumbers(Long id){
...
def regss = RaceRegistration.createCriteria().list(){
eq('compositeEvent', event)
}
regss.each{ r ->
r.raceParticipant.bibNumber = null
r.save()
}
render "Bibs resetted!"
}
If i add flush:true then the bibs are set to null.
regss.each{ r ->
r.raceParticipant.bibNumber = null
r.save(flush: true)
}
I am wondering why you need flush in order for the value to be set to null? I am guessing the problem is with regard to how i am obtain the registration list using createCriteria(). I appreciate any help in this dilemma i am facing. Thanks!
As you probably figured out, save(flush: true) forces Hibernate to write any pending changes to the database. Without the explicit flush, you're relying on a Hibernate transaction to automatically flush when the transaction commits.
The reason only an explicit flush is working for you is because you're not calling save() within a transaction.
The cleanest fix is to create a Grails service, put nullifyBibNumbers() in it, and make the service transactional. That will cause nullifyBibNumbers() to get wrapped in a transaction so that you can use save() without an explicit flush.
If nullifyBibNumbers() is already in a service, you can add #Transactional to the service class, just keep in mind that it will make all methods (perhaps only the public ones?) transactional. Having said that, you can use #NotTransactional on a method to disable transactions.
The value is null in your domain object. But you are talking about null in the database, I guess?
It shouldn't matter. This is basic ORM. As a developer you don't care about when the flush is done. Typically this would be at the end of a transaction. The ORM will then flush all of the changes for that transaction at once.
It works on what is called the first-level cache during the transaction, and tries to avoid going to the db until it is explicitly requested (flush:true) or required (end of transaction).
Without the using of
save(flush: true)
The object will not be persisted immediately.
You can follow the documentation link and see the following information:
The save method informs the persistence context that an instance
should be saved or updated. The object will not be persisted
immediately unless the flush argument is used.
Related to the null issue you are facing make sure that the following condition are met.
The save method returns null if validation failed and the instance was
not persisted, or the instance itself if successful.
You do not need the flush in order for the value to be set to null.
The flush only care of a quick update of the database.
ok i fixed this problem using HQL instead of domain saves. Still i would appreciate why save() didnt work and save(flush:true) saved the data. Thanks!
RaceRegistration.executeUpdate("update RaceRegistration set raceParticipant.bibNumber = null where compositeEvent.id = :ev", [ev: id])
In Parse.com, the help document for updating an object seems to require a query first to retrieve the object before one can update the meta data.
Given that I know the objectId of the object I am updating, do I still have to make this additional call to retrieve everything else about the object before I can send an update call (via saveInBackground)?
Yes, you do. In order to update an object from parse, you must have a local copy.
In order to make a call to update an object - which can take several forms of save or saveInBackground or saveEventually, etc. - you must first make a query to have a copy of the object.
If you know the objectId, is sounds like you have already run a query on an associated object - why not get the full object then with an includeKey: call? https://www.parse.com/docs/ios_guide#queries-relational/iOS
I am using valueUnbound method of HttpSessionBindingListener to release lock(an entry from the database), before session is about to expire:
#Override
public void valueUnbound(HttpSessionBindingEvent event) {
String user = (String) event.getSession().getAttribute("currentUsr");
removeLock(user);
}
When the lock is set, I am setting up the username as a session variable.
I need this "username" in my remove lock method. But the getAttribute is throwing an exception:
java.lang.IllegalStateException: getAttribute: Session already invalidated
I need help in getting the session variable?? or is there any other way to get the username?
No, since session has been invalidated.
Although, I figured out the solution, I am setting the attribute via servlet context in
valueBound method and getting it through the : event.getSession().getServletContext().getAttribute("cUser");
it works fine. Thank You EJP
I got your point EJP, you are right , I am making it complex, I can get it from event.getValue() . +1 to your answer, Thank You.
Although, I figured out the solution, I am setting the attribute via servlet context in valueBound method and getting it through the : event.getSession().getServletContext().getAttribute("cUser");
So.. You are storing session scoped data in the application scope. Do you realize that this way the data is shared among all visitors of the webapp? Visitor X would then see the attribute set by visitor Y which has visited the website at a later moment. It makes the problem only worse.
Anyway, as to the concrete problem, as the exception message is trying to tell you, the session has already been invalidated at that point. There are two ways to solve this:
Make currentUsr a property of the class which is implementing HttpSessionBindingListener, so that you don't need to grab it as a distinct session attribute.
Use a HttpSessionListener instead. The sessionDestroyed() method is called right before invalidation, so you should still have access to all attributes.
i am working on CallLogs Sync Application in Blackberry and partially i have done it, one point that i didn't understand is how to add information to CallLogs. I have retrieved information from CallLogs and Store on Server but now i retrieved information from Server but how to add info to CallLogs didn't come in my mind as i retrieved all the information in Strings from Server and PhoneCallLog Constructor look like this:
PhoneCallLog call = new PhoneCallLog(Date,int Type,int Duration,int Status,participantID participant,String Notes);
Please tell me as soon as Possible, i will be very thankful to you.
class net.rim.blackberry.api.phone.phonelogs.PhoneLogs has method addCall(CallLog call) that adds a log item.
create PhoneCallLog instance with the constructor you posted and add it to PhoneLogs. You need to have the app signed to use these methods. (see http://www.blackberry.com/go/codesigning )
API documentation:
http://docs.blackberry.com/en/developers/deliverables/6022/net/rim/blackberry/api/phone/phonelogs/PhoneLogs.html
http://docs.blackberry.com/en/developers/deliverables/6022/net/rim/blackberry/api/phone/phonelogs/PhoneCallLog.html