QNetworkAccessManager doesn't call finished signal

[Swiftie]

anda_skoa, thanks for reply!

Oh it's my fault, 12 hours with PC is a bad thing

I forgot to create a new instance:

AppApi a;
a.makeRequest();

AppApi a;
a.makeRequest();

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Here the "solution".

AppApi *a = new AppApi;
a->makeRequest();

AppApi *a = new AppApi;
a->makeRequest();

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Some questions.
- How i can make async requests and return response without creating new instances for AppApi? (static functions?)
For example, i have a class UserApi which inherits AppApi and i need able to use makeRequest().

- Should i use deleteLater() after i process request response?

Thanks

[anda_skoa]

Some questions.
- How i can make async requests and return response without creating new instances for AppApi? (static functions?)

You will always need an instance of the network access manager.
And you will need some object instance for the slots.

So a static method could create a network access manager, initiate the request, return both the manager and the reply and the caller could connect to its own slot.
But the only thing you "safe" is the line that creates the manager, the two lines that create the request and the get() call.

Why is creating an object of the Api class something you don't want to do?
Sounds like common delegation to me.

For example, i have a class UserApi which inherits AppApi and i need able to use makeRequest().

Well, in this case the UserApi object is an instance of AppApi.

- Should i use deleteLater() after i process request response?

Yes.

Cheers,
_

[Swiftie]

Thanks for reply,
Here the some changes i made

void AppApi::replyFinished(QNetworkReply* reply)
{
    qDebug() << "replyFinished" << reply;
    reply->deleteLater();
}

void AppApi::replyFinished(QNetworkReply* reply)
{
    qDebug() << "replyFinished" << reply;
    reply->deleteLater();
}

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Here the UserApi class:

#include "../appapi.h"
 
class UserApi : public AppApi
{
public:
    UserApi();
    void sendMessage();
};

#include "../appapi.h"

class UserApi : public AppApi
{
public:
    UserApi();
    void sendMessage();
};

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#include "userapi.h"
 
UserApi::UserApi()
{
}
 
QString UserApi::sendMessage()
{
    // Processing content, etc
    AppApi api;
    api.makeRequest();
}

#include "userapi.h"

UserApi::UserApi()
{
}

QString UserApi::sendMessage()
{
    // Processing content, etc
    AppApi api;
    api.makeRequest();
}

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Somewhere in code

UserApi *c = new UserApi;
c->sendMessage();

UserApi *c = new UserApi;
c->sendMessage();

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Raises Segmentation fault.
I know it's a lame code, but after 2 years of Python i forgot even a basics of C++ and it's my first project in Qt.

Can you explain how properly i make request from UserApi (for example) and return response.

Best regards

[anda_skoa]

UserApi is derived from AppApi, it is an instance of AppApi, just like in Python.

So just call the implementation of the base class

QString UserApi::sendMessage()
{
    makeRequest(); // method of base class AppApi.
 
    // return missing here. this is not a void method
}

QString UserApi::sendMessage()
{
    makeRequest(); // method of base class AppApi.

    // return missing here. this is not a void method
}

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Also make sure you connect the manager's finished() signal only once, e.g. right after you create the manager.

Cheers,
_

[Swiftie]

Thanks, i figured out.

And the last question, it's how to properly return the response?
I know how to "return" response in synchronous mode (using QEventLoop), but i need to implement returning response from async requests.
Here the "example"

UserApi *c = new UserApi;
QJsonDocument j = QJsonDocument::fromJson(c->sendMessage(..parameters here..)); // c->sendMessage needs to return response from GET request

UserApi *c = new UserApi;
QJsonDocument j = QJsonDocument::fromJson(c->sendMessage(..parameters here..)); // c->sendMessage needs to return response from GET request

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Best regards

[anda_skoa]

You get the data in replyFinished() from the QNetworkReply object.

Then you send it in a signal of your class if you want to handle it outside that object or call a virtual method that you implement in UserApi.

Returning is inherently synchronous.

Cheers,
_