Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Why is there no copying at QNetworCookieJar?

Why is there no copying at QNetworCookieJar?

Scheduled Pinned Locked Moved General and Desktop
26 Posts 4 Posters 12.0k Views
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • G Offline
    G Offline
    goetz
    wrote on last edited by
    #8

    You could subclass QNetworkObjectJar, and implement a clone function like this:

    @
    MyNetworkCookieJar* MyNetworkCookieJar::getClone() const {
    MyNetworkCookieJar *newJar = new MyNetworkCookieJar;
    newJar->setAllCookies( allCookies() );
    return newJar
    }
    @

    But watch out: you must delete the returned pointer yourself. There is NO way of treating QObject derived classes as value types!

    http://www.catb.org/~esr/faqs/smart-questions.html

    1 Reply Last reply
    0
    • H Offline
      H Offline
      haithun
      wrote on last edited by
      #9

      That was the idea I also had first but keep in mind that that the CooieJar also can connect some cookies with an URI. This connections will be lost if do like you discribed.

      1 Reply Last reply
      0
      • G Offline
        G Offline
        goetz
        wrote on last edited by
        #10

        Class QNetworkCookie contains the URI the cookie is bound to. According to the API docs the methods allCookies() and setAllCookies() can be used to implement a permanent cookie storage. So I think the returned list of cookies contains all the necessary information. If not, I'd definitely call this a bug :-)

        http://www.catb.org/~esr/faqs/smart-questions.html

        1 Reply Last reply
        0
        • H Offline
          H Offline
          haithun
          wrote on last edited by
          #11

          Your right the data is being set up in QNetworkCookie. So your funtion will work and I am happy now that I do not have to use this cast. :) Thanks

          1 Reply Last reply
          0
          • H Offline
            H Offline
            haithun
            wrote on last edited by
            #12

            Hi,
            I realized that my problem description was insufficient and the problem has not been solved yet.
            I want to do something like this:
            @void Class::SetCookieList(const QList<QNetworkCookie> &Cookies)
            {
            _CookieJar->setAllCookies(Cookies);
            }

            QList<QNetworkCookie> Class::CookieList() const
            {
            return _CookieJar->allCookies();
            }@

            But since the functions "setAllCookies" and "allCookies" are protected I am unable to do so. What is the proper way to do what I want to do?

            1 Reply Last reply
            0
            • ? This user is from outside of this forum
              ? This user is from outside of this forum
              Guest
              wrote on last edited by
              #13

              the docs say:

              bq.
              This function is suitable for derived classes to save cookies to disk, ....

              So should you extend QNetworkCookieJar class and override these methods?

              1 Reply Last reply
              0
              • A Offline
                A Offline
                andre
                wrote on last edited by
                #14

                [quote author="haithun" date="1287528028"]Hi,
                I realized that my problem description was insufficient and the problem has not been solved yet.
                I want to do something like this:
                @void Class::SetCookieList(const QList<QNetworkCookie> &Cookies)
                {
                _CookieJar->setAllCookies(Cookies);
                }

                QList<QNetworkCookie> Class::CookieList() const
                {
                return _CookieJar->allCookies();
                }@

                But since the functions "setAllCookies" and "allCookies" are protected I am unable to do so. What is the proper way to do what I want to do?[/quote]
                If all you want to do is access those methods from an outside class, then just make a trivial subclass of QNetworkCookieJar and make those two method public. You can then access them from your external class. If what you want to do really belongs to the cookie jar itself, perhaps implementing your functionality in that subclass itself would be a better choice. It may help to keep encapsulation.

                1 Reply Last reply
                0
                • H Offline
                  H Offline
                  haithun
                  wrote on last edited by
                  #15

                  That was also my idea but I have the problem that I want to write the data of a normal QNetworkCookieJar to my class which is quite difficult without a copyconstructor.
                  Anybody knowing a good solution?

                  1 Reply Last reply
                  0
                  • A Offline
                    A Offline
                    andre
                    wrote on last edited by
                    #16

                    Why do you need more than one?

                    1 Reply Last reply
                    0
                    • H Offline
                      H Offline
                      haithun
                      wrote on last edited by
                      #17

                      I dont need more than one but I want to give my function "SetCookieJar" a QNetworkCookie. Thats data should be saved in my extended class. I am doing this because I want to avoid to have two member variables and the different treatment in my functions.

                      1 Reply Last reply
                      0
                      • G Offline
                        G Offline
                        goetz
                        wrote on last edited by
                        #18

                        So as Andre wrote - subclass QNetworkCookieJar, make the two protected functions public and use them to transfer the cookie data. No need for a copy constructor as far as I see. Left alone that a copy constructor would do quite the same.

                        @
                        this->setAllCookies(other->allCookies());
                        @

                        Or implement a cloneFromOther Method to simulate an assignment operator/copy constructor:

                        @
                        void MyCookieJar::cloneFromOther(const QNetworkCookieJar *other)
                        {
                        if(other)
                        setAllCookies(other->allCookies())
                        }
                        @

                        As mentioned before, QNetworkCookieJar is a QObject and there simply IS NO copy constructor. It does not help to ask again and again - the trolls will not add it :-)

                        http://www.catb.org/~esr/faqs/smart-questions.html

                        1 Reply Last reply
                        0
                        • H Offline
                          H Offline
                          haithun
                          wrote on last edited by
                          #19

                          I understood that there is no copy cunstructor and also the reason.
                          Well your code is very similar to the one that I wrote cause subclassing QNetworkCookieJar was also my idea. But your version wont work, because you try to call the protected "allCookies()" function of the "other" object as if it's public. Would it be public my problem would not exist.

                          1 Reply Last reply
                          0
                          • G Offline
                            G Offline
                            goetz
                            wrote on last edited by
                            #20

                            If you derive class MyCookieJar from QNetworkCookieJar you have access to the protected methods of the base class QNetworkCookieJar. And of course you have access to the protected methods of the other object pointer in that method.

                            http://www.catb.org/~esr/faqs/smart-questions.html

                            1 Reply Last reply
                            0
                            • H Offline
                              H Offline
                              haithun
                              wrote on last edited by
                              #21

                              Well I tried to do it in a constructor of my class but it wont work.

                              Here the class with constructor:
                              @
                              class MyClass : public QNetworkCookieJar
                              {
                              Q_OBJECT
                              public:

                              CopyFromCookieJar(QNetworkCookieJar *Cookies, QObject *parent = 0) : NetworkCookieJar(parent)
                              {
                                  this->setAllCookies(Cookies->allCookies());
                              }
                              

                              @

                              1 Reply Last reply
                              0
                              • G Offline
                                G Offline
                                goetz
                                wrote on last edited by
                                #22

                                The code fragment wouldn't even compile:

                                Your class is named "MyClass", your Constructor is named "CopyFromCookieJar" - both names must be equal.

                                Also the argument of the constructor should be
                                @const QNetworkCookieJar *Cookies@

                                Additionally, you should check for a null pointer before calling any methods on the pointer.

                                http://www.catb.org/~esr/faqs/smart-questions.html

                                1 Reply Last reply
                                0
                                • H Offline
                                  H Offline
                                  haithun
                                  wrote on last edited by
                                  #23

                                  Yeah sry I just changed the name of the function and forgot that it should be a constructor.

                                  Why do you declare the pointer as const?

                                  The reason of the compiler is "'QList<QNetworkCookie> QNetworkCookieJar::allCookies() const' is protected".

                                  1 Reply Last reply
                                  0
                                  • G Offline
                                    G Offline
                                    goetz
                                    wrote on last edited by
                                    #24

                                    Sorry for the wrong guidance. You cannot access the protected method of the base class in a derived class using a base class pointer.

                                    You must replace all appearences of QNetworkCookieJar with your derived class in your application and pass around only pointers/references of this derived class. Then you have access to the protected methods.

                                    @
                                    class MyCookieJar : public QNetworkCookieJar
                                    {
                                    Q_OBJECT
                                    public:
                                    explicit MyCookieJar(QObject *parent = 0)
                                    : QNetworkCookieJar(parent)
                                    {
                                    // nothing
                                    }

                                    void cloneFromOther(const MyCookieJar *other) {
                                        setAllCookies(other->allCookies());
                                    }
                                    

                                    };
                                    @

                                    For the const pointer:
                                    the other cookie jar will not be changed by the clone method (or the copy constructor), so it's actually a good idea to make the pointer const. There are good explanations on const correctnes on the "C++ FAQ":http://www.parashift.com/c++-faq-lite/const-correctness.html

                                    http://www.catb.org/~esr/faqs/smart-questions.html

                                    1 Reply Last reply
                                    0
                                    • H Offline
                                      H Offline
                                      haithun
                                      wrote on last edited by
                                      #25

                                      Yeah but now we are right there where I started cause I did not want to pass my derived class. I want to pass a QNetworkCookieJar to the function and then I want to put the cookies into my derived class. The reason why I want to have just Qt classes is no real reason it's just that I hate it to include the header in every upcoming projects.

                                      I guess my first version by using a reinterpretate cast is the only solution.

                                      1 Reply Last reply
                                      0
                                      • G Offline
                                        G Offline
                                        goetz
                                        wrote on last edited by
                                        #26

                                        Then there's no solution to your problem - you can't have your cake and eat it too :-)

                                        I would go for the subclass approach. reinterpret_cast is ugly and should be avoided whenever theres a more elegant (and save!) solution - just my 0,02 € - :-)

                                        http://www.catb.org/~esr/faqs/smart-questions.html

                                        1 Reply Last reply
                                        0

                                        • Login

                                        • Login or register to search.
                                        • First post
                                          Last post
                                        0
                                        • Categories
                                        • Recent
                                        • Tags
                                        • Popular
                                        • Users
                                        • Groups
                                        • Search
                                        • Get Qt Extensions
                                        • Unsolved