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Cannot get data from HTTP request

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  • SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #6

    You should move the Qt 5 new syntax. It would have show you that error is not part of QNetworkAccessManager and that the signature of ssErrors is wrong.

    Interested in AI ? www.idiap.ch
    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

    1 Reply Last reply
    1
    • T Offline
      T Offline
      t0msk
      wrote on last edited by
      #7

      @SGaist said in Cannot get data from HTTP request:

      You should move the Qt 5 new syntax. It would have show you that error is not part of QNetworkAccessManager and that the signature of ssErrors is wrong.

      Which syntax? I use Qt5.

      I tried even:

          QNetworkReply *reply = manager->get(request);
      
          connect(reply, SIGNAL(finished(reply)), this, SLOT(replyFinished(reply)));
      
          connect(reply, SIGNAL(error(reply)), this, SLOT(replyFinished(reply)));
      
          connect(reply, SIGNAL(sslErrors(reply)), this, SLOT(replyFinished(reply)));
      

      Student who loves C/C++

      mrjjM 1 Reply Last reply
      0
      • T t0msk

        @SGaist said in Cannot get data from HTTP request:

        You should move the Qt 5 new syntax. It would have show you that error is not part of QNetworkAccessManager and that the signature of ssErrors is wrong.

        Which syntax? I use Qt5.

        I tried even:

            QNetworkReply *reply = manager->get(request);
        
            connect(reply, SIGNAL(finished(reply)), this, SLOT(replyFinished(reply)));
        
            connect(reply, SIGNAL(error(reply)), this, SLOT(replyFinished(reply)));
        
            connect(reply, SIGNAL(sslErrors(reply)), this, SLOT(replyFinished(reply)));
        
        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by mrjj
        #8

        @t0msk
        Hi
        The SIGNAL and SLOT macros is the "old way"
        its explained here
        https://wiki.qt.io/New_Signal_Slot_Syntax

        The main benefit is that it gives errors at compile time if its not correct.
        The SIGNAL and SLOT will eat most things and not complain but simply
        fail to work at runtime.

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        • T Offline
          T Offline
          t0msk
          wrote on last edited by
          #9

          So I tried this:

          connect(
                  reply, &reply::finished,
                  this, &Manager::replyFinished
              );
          

          And I get:

          error: 'reply' is not a class, namespace, or enumeration
          

          I quite don't understand what to put into &reply yet :)

          Student who loves C/C++

          1 Reply Last reply
          0
          • SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #10

            The name of the class containing the signal, same goes for the last parameter, it's the name of the class containing the slot.

            Interested in AI ? www.idiap.ch
            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

            T 1 Reply Last reply
            1
            • SGaistS SGaist

              The name of the class containing the signal, same goes for the last parameter, it's the name of the class containing the slot.

              T Offline
              T Offline
              t0msk
              wrote on last edited by t0msk
              #11

              @SGaist

              Changed it to this:

              connect(
                      reply, &QNetworkReply::finished,
                      this, &Manager::replyFinished
                  );
              

              And I get:

              /usr/include/qt/QtCore/qobject.h:243: error: static assertion failed: The slot requires more arguments than the signal provides.
                243 |         Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= int(SlotType::ArgumentCount),
                    |         ^~~~~~~~~~~~~~~~~
              

              Student who loves C/C++

              mrjjM 1 Reply Last reply
              0
              • T t0msk

                @SGaist

                Changed it to this:

                connect(
                        reply, &QNetworkReply::finished,
                        this, &Manager::replyFinished
                    );
                

                And I get:

                /usr/include/qt/QtCore/qobject.h:243: error: static assertion failed: The slot requires more arguments than the signal provides.
                  243 |         Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= int(SlotType::ArgumentCount),
                      |         ^~~~~~~~~~~~~~~~~
                
                mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by mrjj
                #12

                @t0msk said in Cannot get data from HTTP request:

                QNetworkReply::finished,

                Well you are mixing the classes/signals.
                The reply's signals is
                https://doc.qt.io/qt-5/qnetworkreply.html#finished
                and have no QNetworkReply* parameter.

                so i think you mean

                connect(
                        Manager, &QNetworkAccessManager::finished,
                        this, &Manager::replyFinished
                    );
                
                T 1 Reply Last reply
                1
                • mrjjM mrjj

                  @t0msk said in Cannot get data from HTTP request:

                  QNetworkReply::finished,

                  Well you are mixing the classes/signals.
                  The reply's signals is
                  https://doc.qt.io/qt-5/qnetworkreply.html#finished
                  and have no QNetworkReply* parameter.

                  so i think you mean

                  connect(
                          Manager, &QNetworkAccessManager::finished,
                          this, &Manager::replyFinished
                      );
                  
                  T Offline
                  T Offline
                  t0msk
                  wrote on last edited by
                  #13

                  @mrjj said in Cannot get data from HTTP request:

                  @t0msk said in Cannot get data from HTTP request:

                  QNetworkReply::finished,

                  Well you are mixing the classes.
                  The reply signals is
                  https://doc.qt.io/qt-5/qnetworkreply.html#finished
                  and have no QNetworkReply* parameter.

                  so i think you mean

                  connect(
                          Manager, &QNetworkAccessManager::finished,
                          this, &Manager::replyFinished
                      );
                  

                  Thank you,
                  so now I have:

                      QSslConfiguration config = QSslConfiguration::defaultConfiguration();
                      config.setProtocol(QSsl::TlsV1_2);
                      QNetworkAccessManager *manager = new QNetworkAccessManager();
                      QNetworkRequest request;
                  
                  
                      request.setHeader(QNetworkRequest::ServerHeader, "application/json");
                      request.setSslConfiguration(config);
                      request.setUrl(QUrl("https://www.archlinux.org/packages/search/json/?q=dolphin"));
                  
                      QNetworkReply *reply = manager->get(request);
                  
                      connect(
                          manager, &QNetworkAccessManager::finished,
                          this, &Manager::replyFinished
                      );
                  
                      connect(
                          manager, &QNetworkAccessManager::sslErrors,
                          this, &Manager::replyFinished
                      );
                  
                  void Manager::replyFinished(QNetworkReply *reply)
                  {
                      qDebug() << reply->readAll();
                  
                      QString ha = reply->readAll();
                  
                      QString he;
                  }
                  

                  Still no output and no error :/

                  Student who loves C/C++

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                  0
                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #14

                    Hi
                    Its a bit odd to connect all to the same slot but lets leave it for now.

                    now its time to
                    check your openSSL support !

                    what does
                    qDebug() << "i can use HTTPS:" << QSslSocket::supportsSsl();
                    qDebug() << "version" << QSslSocket::sslLibraryBuildVersionString();

                    say ?

                    T 1 Reply Last reply
                    1
                    • mrjjM mrjj

                      Hi
                      Its a bit odd to connect all to the same slot but lets leave it for now.

                      now its time to
                      check your openSSL support !

                      what does
                      qDebug() << "i can use HTTPS:" << QSslSocket::supportsSsl();
                      qDebug() << "version" << QSslSocket::sslLibraryBuildVersionString();

                      say ?

                      T Offline
                      T Offline
                      t0msk
                      wrote on last edited by
                      #15

                      @mrjj
                      It says:

                      i can use HTTPS: true
                      version "OpenSSL 1.1.1c  28 May 2019"
                      

                      Student who loves C/C++

                      1 Reply Last reply
                      1
                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #16

                        What version of Qt are you using ?

                        One more thing: do these connections prior to calling get.

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        T 1 Reply Last reply
                        0
                        • SGaistS SGaist

                          What version of Qt are you using ?

                          One more thing: do these connections prior to calling get.

                          T Offline
                          T Offline
                          t0msk
                          wrote on last edited by
                          #17

                          @SGaist Qt version is 5.13.1

                          Student who loves C/C++

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                          • T Offline
                            T Offline
                            t0msk
                            wrote on last edited by
                            #18

                            So where can be problem? :/

                            Student who loves C/C++

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                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by SGaist
                              #19

                              Did you move the connection statements as I suggested ?

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              T 1 Reply Last reply
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                              • SGaistS SGaist

                                Did you move the connection statements as I suggested ?

                                T Offline
                                T Offline
                                t0msk
                                wrote on last edited by
                                #20

                                @SGaist I dont know what do you mean

                                Student who loves C/C++

                                JonBJ 1 Reply Last reply
                                0
                                • T t0msk

                                  @SGaist I dont know what do you mean

                                  JonBJ Online
                                  JonBJ Online
                                  JonB
                                  wrote on last edited by JonB
                                  #21

                                  @t0msk

                                  @SGaist wrote

                                  Did you move the connection statements as I suggested ?

                                  In your code you show:

                                      QNetworkReply *reply = manager->get(request);
                                  
                                      connect(
                                          manager, &QNetworkAccessManager::finished,
                                          this, &Manager::replyFinished
                                      );
                                  
                                      connect(
                                          manager, &QNetworkAccessManager::sslErrors,
                                          this, &Manager::replyFinished
                                      );
                                  

                                  You are calling the manager->get(request) before you have connected the signals/slots on manager, which may/will be too late. He is asking you to change over anything like that to

                                      connect(
                                          manager, &QNetworkAccessManager::finished,
                                          this, &Manager::replyFinished
                                      );
                                  
                                      connect(
                                          manager, &QNetworkAccessManager::sslErrors,
                                          this, &Manager::replyFinished
                                      );
                                  
                                      QNetworkReply *reply = manager->get(request);
                                  

                                  so you move the connection statements to before the get(request). So we get to see finished or quite possibly errors from the request. In general, you need to set up signals/slots as soon as you create an object (manager here), before you call anything which could raise a signal.

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                                  • T Offline
                                    T Offline
                                    t0msk
                                    wrote on last edited by
                                    #22

                                    Changed it like:

                                        connect(
                                            manager, &QNetworkAccessManager::finished,
                                            this, &Manager::replyFinished
                                        );
                                    
                                        connect(
                                            manager, &QNetworkAccessManager::sslErrors,
                                            this, &Manager::replyFinished
                                        );
                                    
                                        QNetworkReply *reply = manager->get(request);
                                    

                                    and still doesn't work, no error, no reply.

                                    Student who loves C/C++

                                    1 Reply Last reply
                                    0

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