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. Cannot get data from HTTP request
Forum Updated to NodeBB v4.3 + New Features

Cannot get data from HTTP request

Scheduled Pinned Locked Moved Unsolved General and Desktop
22 Posts 5 Posters 2.7k Views 3 Watching
  • 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.
  • T Offline
    T Offline
    t0msk
    wrote on 15 Oct 2019, 20:33 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++

    M 1 Reply Last reply 15 Oct 2019, 20:37
    0
    • T t0msk
      15 Oct 2019, 20:33

      @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)));
      
      M Offline
      M Offline
      mrjj
      Lifetime Qt Champion
      wrote on 15 Oct 2019, 20:37 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.

      1 Reply Last reply
      1
      • T Offline
        T Offline
        t0msk
        wrote on 15 Oct 2019, 21:01 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
        • S Offline
          S Offline
          SGaist
          Lifetime Qt Champion
          wrote on 15 Oct 2019, 21:10 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 15 Oct 2019, 21:14
          1
          • S SGaist
            15 Oct 2019, 21:10

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

            T Offline
            T Offline
            t0msk
            wrote on 15 Oct 2019, 21:14 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++

            M 1 Reply Last reply 15 Oct 2019, 21:18
            0
            • T t0msk
              15 Oct 2019, 21:14

              @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),
                    |         ^~~~~~~~~~~~~~~~~
              
              M Offline
              M Offline
              mrjj
              Lifetime Qt Champion
              wrote on 15 Oct 2019, 21:18 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 15 Oct 2019, 21:24
              1
              • M mrjj
                15 Oct 2019, 21:18

                @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 15 Oct 2019, 21:24 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++

                1 Reply Last reply
                0
                • M Offline
                  M Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on 15 Oct 2019, 21:27 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 15 Oct 2019, 21:30
                  1
                  • M mrjj
                    15 Oct 2019, 21:27

                    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 15 Oct 2019, 21:30 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
                    • S Offline
                      S Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on 15 Oct 2019, 21:32 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 15 Oct 2019, 21:35
                      0
                      • S SGaist
                        15 Oct 2019, 21:32

                        What version of Qt are you using ?

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

                        T Offline
                        T Offline
                        t0msk
                        wrote on 15 Oct 2019, 21:35 last edited by
                        #17

                        @SGaist Qt version is 5.13.1

                        Student who loves C/C++

                        1 Reply Last reply
                        0
                        • T Offline
                          T Offline
                          t0msk
                          wrote on 16 Oct 2019, 20:20 last edited by
                          #18

                          So where can be problem? :/

                          Student who loves C/C++

                          1 Reply Last reply
                          0
                          • S Offline
                            S Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on 16 Oct 2019, 20:44 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 17 Oct 2019, 17:13
                            0
                            • S SGaist
                              16 Oct 2019, 20:44

                              Did you move the connection statements as I suggested ?

                              T Offline
                              T Offline
                              t0msk
                              wrote on 17 Oct 2019, 17:13 last edited by
                              #20

                              @SGaist I dont know what do you mean

                              Student who loves C/C++

                              J 1 Reply Last reply 17 Oct 2019, 17:42
                              0
                              • T t0msk
                                17 Oct 2019, 17:13

                                @SGaist I dont know what do you mean

                                J Offline
                                J Offline
                                JonB
                                wrote on 17 Oct 2019, 17:42 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.

                                1 Reply Last reply
                                4
                                • T Offline
                                  T Offline
                                  t0msk
                                  wrote on 19 Oct 2019, 13:18 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

                                  16/22

                                  15 Oct 2019, 21:32

                                  • Login

                                  • Login or register to search.
                                  16 out of 22
                                  • First post
                                    16/22
                                    Last post
                                  0
                                  • Categories
                                  • Recent
                                  • Tags
                                  • Popular
                                  • Users
                                  • Groups
                                  • Search
                                  • Get Qt Extensions
                                  • Unsolved