windows app for simle API get : TLS initialization failed

SGaist

Hi and welcome to devnet,

What version of Qt are you using ?
On what platform ?
What version of OpenSSL do you have ?
How did you install it ?

louis cordhomme

hi,
i use Qt 5.13.2
on windows 10
i don't learn ssl, into i don't know (it is certainly my probleme)

SGaist

What compiler are you using ?

You have to install OpenSSL 1.1 and it should be built with the same compiler you are using with Qt.

louis cordhomme

i use MinGW 64Bit
i've download a openssl.zip but i don't understand why install it ?

SGaist

Why ? Because Qt does not provide OpenSSL due to some international restriction. You have to provide OpenSSL yourself if your application need some it.

louis cordhomme

haa ok,
but how do we provide OpenSSL then?
Sorry about my lack of knowledge of the subject
Thank you very much.

louis cordhomme

It's okay, I actually made it.

SGaist

Everything is working ?

louis cordhomme

almost,
I'm getting to have my xml thong
but my "onmanagerfinished" method only runs after my on _button_clicked method.

my constructor :

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    manager = new QNetworkAccessManager();                      
    QObject::connect(manager,&QNetworkAccessManager::finished,  
                     this, [=](QNetworkReply *reply) {          
        if (reply->error()) {
            qDebug() << reply->errorString();
            return;
        }
        answer = reply->readAll();
        qDebug() << answer;
    });

but it's return this (qDebug())

#########################################OKbegin

#########################################GetuuidBegin

#########################################GetuuidEnd 
Answer ---->  ""

#########################################OKend 
UUID -------> ""
"{\"id\":\"069a79f444e94726a5befca90e38aaf5\",\"name\":\"Notch\"}"

my methodes :

QString MainWindow::GetUUID(QString Pseudo)
{
    qDebug()<<"\n#########################################GetuuidBegin";

    QString str = "https://api.mojang.com/users/profiles/minecraft/" + Pseudo + "?at=" + getTimeStamp();   
    request.setUrl(QUrl(str));                                                                             
    manager->get(request);                                                                                 

    qDebug()<<"\n#########################################GetuuidEnd"
            <<"\nAnswer ----> "<< answer;

    return  answer;
}

void MainWindow::on_OK_clicked()
{
    qDebug() <<"\n#########################################OKbegin";
    QString UUID = GetUUID(ui->Speudo->text());

    qDebug() <<"\n#########################################OKend"
             << "\nUUID ------->"<< UUID;

PS : what I call onManagerFinished is:

[=](QNetworkReply *reply) {          
        if (reply->error()) {
            qDebug() << reply->errorString();
            return;
        }
        answer = reply->readAll();
        qDebug() << answer;
    }

because I used to use an onManagerFinished method instead

SGaist

Your slot (well lambda in this case) will be called asynchronously at some point when the answer to the request is completely received. What you are doing now is calling your qDebug statement right after you made your request which is not yet done or might not even have been sent to the server yet.

louis cordhomme

yes I understand I only receive the answer when it is completely received, so I need to use reply.isFinished(), but where ? I'm not sure I understand how to use it (even with the doc)

mrjj

@louis-cordhomme said in windows app for simle API get : TLS initialization failed:

reply.isFinished()

Hi
Consider just using signal and slot to solve this asynchronously.
(minwindow.h, define a new signal )

signal:
void AnswerReady(QString Pseudo);

then in your

QObject::connect(manager,&QNetworkAccessManager::finished,  
                     this, [=](QNetworkReply *reply) {          
        if (reply->error()) {
            qDebug() << reply->errorString();
            return;
        }
        answer = reply->readAll();
        qDebug() << answer;
       emit AnswerReady(answer); // tell the world
    });

then connect this new signal to lambda or slot where you do what ever you want to do with the
data
connect ( this,&Mainwindow::AnswerReady, this, &Mainwindow::ProcessAnswer);

void MainWindow::ProcessAnswer(QString answer)
{
    qDebug()<<"\n#########################################GetuuidEnd"
            <<"\nAnswer ----> "<< answer;  
}

louis cordhomme

Actually I'm going to have several different requests to make and I wanted to make methods like getUUID or getXXX
I'm not sure I understand how to use ProcessAnswer

mrjj

@louis-cordhomme
Hi
Well the QNetworkAccessManager is by nature asynchronous so you have to code to support that.

one way to handle reading different data is to use member variables to keep the state in.

void MainWindow::ProcessAnswer(QString answer) {
if ( ReadingType == UUID)
// use answer for that

if ( ReadingType == SOMEOTHER)
// use answer for that
}

Its also possible to connect to signal finished on the QNetworkReply and in that way know which request has which data.

I know you wish to do

NetworkAccessManager NAManager;
QUrl url ("http://www.google.com");
QNetworkRequest request(url);
QNetworkReply *reply = NAManager.get(request);
QEventLoop eventLoop;
QObject::connect(reply, SIGNAL(finished()), &eventLoop, SLOT(quit()));
eventLoop.exec(); // it stays in here until its finished.
std::cout << "finished" << std::endl; //request finished here

where is synchronous in nature and feels easier to code but its kinda bad design and should be avoided.

SGaist

Is there a set of steps to follow one after the other ?
If so, you may want to consider using a state machine to model that.